Tower type photo-thermal power station one-key start-stop control method and system

Abstract

The invention provides a one-key start and stop control method and system for a tower type photo-thermal power station, and belongs to the technical field of tower type photo-thermal power stations. Molten salt pipeline electric heat tracing preheating sequence control, steam generator water feeding temperature control sequence control, mirror field starting sequence control, cold salt pump starting sequence control, heat absorption tower molten salt bypass salt filling sequence control, heat absorber main path salt filling sequence control, vacuum system sequence control, steam generator cold salt filling sequence control, steam generator hot salt feeding sequence control and shaft seal system input sequence control are started in sequence. A steam bypass system is put into sequence control, and a turbine starts sequence control; and during stopping, sequentially starting steam turbine stop sequence control, mirror field stop sequence control, heat absorber salt dredging sequence control, cold salt pump stop sequence control, vacuum system stop sequence control, steam generator salt dredging sequence control, shaft seal system stop sequence control and auxiliary machine system stop sequence control. The operation process of the power station is simplified, the possibility of manual operation errors is reduced, and the operation accuracy is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of tower-type solar thermal power plants, and particularly relates to a one-key start-stop control method and system for a tower-type solar thermal power plant. Background Art

[0002] As a system that converts solar energy into heat energy and generates electricity through a heat-work conversion process, solar thermal power generation has the advantages of being clean, renewable, efficient, and energy-storable, and is a new energy power generation method with great development potential. In recent years, the solar thermal power generation industry has developed rapidly, with the project scale continuously expanding and the technical level gradually improving. The tower-type solar thermal power plant is one of the important forms of solar thermal power generation technology. It has a high concentration ratio, a high solar-thermal conversion efficiency, and a short heat transfer path, and is very suitable for large-scale and large-capacity commercial applications.

[0003] When the tower-type solar thermal power plant is operating normally, the equipment of the unit must be started or stopped in a certain order. However, there are the following problems in the start-stop operation of the current tower-type solar thermal power plant: the solar island control system of the tower-type solar thermal power plant is complex, with a large number of equipment, and the start-stop sequence requirements are strict. The operating personnel need to be familiar with the start-stop sequence. Once the operation sequence is incorrect, it is very likely to cause equipment damage; moreover, due to the relatively small contact of the operating personnel and the involvement of more new technologies, their proficiency will directly affect the start-stop efficiency of the unit, which not only increases the training difficulty and cost of the operating personnel, but also reduces the overall operating efficiency of the power plant.

[0004] Therefore, the present invention provides a one-key start-stop control system for a tower-type solar thermal power plant. Summary of the Invention

[0005] The present invention provides a one-key start-stop control method and system for a tower-type solar thermal power plant, so as to at least solve the problems of the risk of equipment damage caused by human errors and the training difficulty and cost of operating personnel in the prior art.

[0006] In a first aspect, an embodiment of the present application provides a one-key start-stop control method for a tower-type solar thermal power plant, and the method includes: At startup, sequentially start the molten salt pipeline electric tracing preheating sequence control, the steam generator water filling temperature control sequence control, the mirror field startup sequence control, the cold salt pump startup sequence control, the molten salt bypass filling sequence control for the absorber tower, the absorber main road filling sequence control, the vacuum system sequence control, the cold salt filling sequence control for the steam generator, the hot salt filling sequence control for the steam generator, the shaft seal system input sequence control, the steam bypass system input sequence control, and the steam turbine startup sequence control; At shutdown, sequentially start the steam turbine shutdown sequence control, the mirror field shutdown sequence control, the absorber desalting sequence control, the cold salt pump shutdown sequence control, the vacuum system shutdown sequence control, the steam generator desalting sequence control, the shaft seal system shutdown sequence control, and the auxiliary system shutdown sequence control.

[0007] Further, start the sequence control for preheating the molten salt pipeline electrically, specifically including: Step S11: Start the electric tracing system for the molten salt pipeline to heat the molten salt pipeline. Step S12: Set the target temperature of the electric tracing to 290°C, and set the current electric tracing temperature command to be 20°C higher than the current pipeline temperature. Step S13: The electric tracing is put into temperature protection. When the temperature rises to 290°C, the electric tracing stops working. When the pipeline temperature drops to 270°C, the electric tracing starts again to maintain the current molten salt pipeline temperature at 290°C. Start the sequence control for controlling the water inlet temperature of the steam generator, specifically including: Step S21: Open the inlet valve of the electric heater and the stop valve of the bypass electric valve of the water supply pipeline. Step S22: After the drum liquid level reaches -200 mm, start the preselected external circulation pump and the forced circulation pump to circulate, and set the other two pumps as standby. Step S23: Gradually increase the frequency converter of the external circulation pump to the preset value, and at the same time start the electric heater of the external circulation pump pipeline. Step S24: When the water temperature is 5°C higher than the molten salt condensation temperature, open the main electric valve of the water supply pipeline. Step S25: After the main electric valve of the water supply pipeline is fully opened, close the bypass electric valve of the water supply pipeline. Start the sequence control for starting the mirror field, specifically including: When the DNI value measured by the meteorological system is greater than 200 W / m², the DCS sends a command to the mirror field control system to start the sequence control for starting the mirror field and turn on the mirror field preheating mode.

[0008] Further, when the mirror field has been started and the molten salt pipeline temperature exceeds the molten salt condensation point, start the sequence control for starting the cold salt pump, specifically including: Step S31: Open the cold salt pump recirculation valve to 50%. Step S32: Start the preselected cold salt pump and open the corresponding outlet valve. Step S33: Set the motor frequency rise rate to 10% per minute and slowly increase the motor frequency to 30% of the pump rated speed. When the pipeline temperatures of the molten salt riser and downcomer in the receiver reach above the freezing point, start the sequence control for filling the molten salt bypass in the absorber tower, specifically including: Step S41: Open the bypass valve of the absorber tower. Step S42: Open the start-up filling valve of the riser. Step S43: Open the regulating valve at the outlet of the cold salt pump. Step S44: Adjust the liquid level in the downcomer in the bypass mode. Step S45: Fully open the regulating valve at the outlet of the salt pump.

[0009] Furthermore, when the temperature of the outer screen of the heat absorber, the temperature of the back plate, and the temperature of the corresponding molten salt pipeline exceed the freezing point of the molten salt, start the sequence control of filling molten salt in the main path of the heat absorber, specifically including: Step S51: Open all valves of the heat absorber; Step S52: The liquid level of the inlet tank > 2000 mm; Step S53: Close the desalting valve of the inlet tank; Step S54: Fill the outlet tank, and the liquid level > -2000 mm; Step S55: Close the desalting valve of the tube screen; Step S56: Close the exhaust valve of the tube screen; Step S57: Close the bypass valve of the heat absorber; Start the mirror field power control mode, specifically including: after closing the bypass valve of the heat absorber, the mirror field enters the power mode, and gradually increase the number of heliostats to increase the heating flow rate of the molten salt; Start the sequence control of the vacuum system, specifically including: Step S61: Close the vacuum break valve; Step S62: Fully open the steam and condensate isolation valve; Step S63: Start all vacuum pumps; Step S64: Confirm that the vacuum value reaches the unit requirement; Step S65: Stop the standby vacuum pump; Step S66: Input the ACC automatic control.

[0010] Furthermore, when the liquid level of the hot salt tank reaches one-fifth of the total range, start the sequence control of filling cold salt in the steam generator, specifically including: Step S71: Open the exhaust valve of the cold salt molten salt pipeline to the air, and close the desalting valve; Step S72: Open the recirculation regulating valve of the cold salt tank temperature regulating pump to the preset position to make the molten salt flow, and set the valve for automatic control to control the outlet pressure of the pump; Step S73: Start the preselected temperature regulating pump, set the frequency converter command at the preset safe frequency, and open the pump outlet valve; Step S74: After the temperature regulating pump starts, delay for 10 seconds and close the exhaust valve to the air; Step S75: Set the outlet regulating valve of the molten salt temperature regulating pipeline to 60%; Step S76: Increase the frequency of the temperature regulating pump to fill the molten salt pipe head of the steam generator with molten salt; Step S77: Open the inlet valve of the molten salt pipeline of the reheater to 100% and set it for automatic control; When the filling of cold salt in the steam generator is completed and the liquid level of the hot salt tank reaches one-fourth of the total range, start the sequence control of feeding hot salt in the steam generator, specifically including: Step S81: Open the vent valve of the hot salt pipeline; Step S82: Open the hot salt pump recirculation valve to a preset position to make the molten salt flow, and set the valve to automatic control for controlling the outlet pressure of the pump; Step S83: Start the preselected hot molten salt pump; Step S84: After the hot salt pump starts, delay for 10 seconds and then close the vent valve; Step S85: Set the hot salt pump outlet regulating valve to automatic control state and set the current steam flow rate as the target value; Step S86: Gradually increase the target value of the hot salt pump outlet regulating valve to the steam turbine required flow rate according to the steam generator startup curve rate.

[0011] Further, after the hot salt feeding sequence control ends, start the shaft seal system and put it into sequence control, specifically including: Step S91: Open the auxiliary steam drain valve; Step S92: When the steam temperature reaches the preset temperature and the steam pressure reaches the preset pressure, open the auxiliary steam stop valve and regulating valve, and set the control target value of the regulating valve to the shaft seal steam supply required pressure; Step S93: Put into operation the shaft seal electric heater, set the temperature to 420 °C, and open the drain valve behind the heater; Step S94: The shaft seal cooling fan is automatically put into operation and start the fan; Step S95: The desuperheating water solenoid valve of the main body drain expansion vessel is put into automatic opening; Step S96: When the pressure and temperature in front of the shaft seal regulating valve reach the requirements, put into operation the low-pressure cylinder rear cylinder spray water solenoid valve automatically; Step S97: When the rear shaft seal pressure reaches the preset value, the shaft seal pressure control is automatically put into operation; Step S98: The low-pressure cylinder rear shaft seal steam supply temperature is automatically put into operation; Step S99: Open the drain valve in front of the shaft seal regulating valve; Step S910: After the shaft seal is put into operation, set the low-pressure cylinder rear shaft seal pressure to the shaft seal preset pressure and set the low-pressure cylinder rear shaft seal temperature to the shaft seal preset temperature.

[0012] Further, start the steam bypass system and put it into sequence control, specifically including: Step S101: Put the high-pressure bypass desuperheating water valve, low-pressure bypass desuperheating water valve and tertiary desuperheating water valve into automatic state, set the control target value of the high-pressure bypass desuperheating water valve to the preset required temperature of the hot re-heater, set the control target value of the low-pressure bypass desuperheating water valve to the preset required temperature of the air-cooled pipeline and the steam turbine, and set the control target value of the tertiary desuperheating water valve to the preset required temperature of the air-cooled system; Step S102: Set the minimum valve position of the high-pressure steam bypass valve and the low-pressure steam bypass valve to 10%; Step S103: Put the high-pressure steam bypass valve and the low-pressure steam bypass valve into the automatic control state, and set the pressure control target values of the high-pressure steam bypass valve and the low-pressure steam bypass valve to the preset required pressure of the steam turbine; Start the turbine startup sequence control, specifically including: After the steam pressure and temperature in the steam generator reach the unit startup conditions, trigger the turbine startup sequence control until the turbine reaches full speed and no load.

[0013] Further, starting from the unit shutdown sequence control, when the unit load has been reduced to the minimum load of the unit according to the requirements of the grid dispatching, start the turbine shutdown sequence control, specifically including: triggering the unit shutdown signal to the steam turbine; Stop the mirror field sequence control, specifically including: The DCS sends instructions to the mirror field control system to gradually reduce the number of focusing heliostats; When the molten salt temperature dropped by the receiver is equal to the condensation point temperature plus 30 degrees, start the salt drainage sequence control of the receiver, specifically including: Step S111: Close the riser regulating valve and the outlet regulating valve of the cold salt pump; Step S112: Close the inlet regulating valve of the tube bank; Step S113: Open the salt drainage valve of the tube bank and control the pressure of the inlet tank; Step S114: Open the salt drainage valve of the tube bank and the salt drainage valve of the inlet tank; Step S115: Control the pressure of the inlet tank at 0.5 bar; Step S116: Open the riser, the inlet regulating valve of the tube bank and the bypass valve of the receiver; Step S117: After the salt drainage is completed, change the set pressure of the inlet tank to -2 bar. After the salt drainage is completed, maintain the preheating mode to gradually cool down the receiver; After the outlet regulating valve of the cold salt pump is closed, start the cold salt pump stop sequence control, specifically including: Step S121: Slowly reduce the output of the cold salt pump to 30%; Step S122: Stop all cold salt pumps and close the outlet valves.

[0014] Further, after the turbine speed reaches zero and the turning gear is put into operation, start the vacuum system stop sequence control, specifically including: Step S131: Stop all vacuum pumps; Step S132: Stop the air-cooled system; Step S133: Open the vacuum break valve; After the turbine speed reaches zero and the turning gear is put into operation, start the salt drainage sequence control of the steam generator, specifically including: Step S141: Stop all temperature control pumps, and close the pump outlet valves and the recirculation regulating valves; Step S142: Stop all hot salt pumps, and close the pump outlet valves and the recirculation regulating valves; Step S143: Open the desalting valve and the exhaust valve; After the sequential control of the vacuum system is completed, start the sequential control of the shaft seal system, specifically including: Step S151: When the vacuum completely reaches zero, close the shaft seal steam supply valve; Step S152: Fully close the shaft seal steam supply regulating valve; Step S153: Close the desuperheating water regulating valve; Step S154: Stop the shaft seal cooler fan; After the shaft seal is withdrawn, start the sequential control of the auxiliary system to stop, specifically including: After the shaft seal is withdrawn, sequentially control and stop the auxiliary system.

[0015] In a second aspect, the embodiments of the present application further provide a one-key start-stop control system applied to the one-key start-stop control method of the tower-type solar thermal power station described in the above aspects. The system includes a unit, a unit start sequential control, and a unit stop sequential control; The unit includes: molten salt pipeline, steam generator, mirror field, cold salt system, hot salt system, absorber tower, vacuum system, shaft seal system, steam bypass system, steam turbine, and auxiliary system; The unit start sequential control includes: molten salt pipeline electric tracing preheating sequential control, steam generator water inlet temperature control sequential control, mirror field start sequential control, cold salt pump start sequential control, absorber tower molten salt bypass salt filling sequential control, absorber main road salt filling sequential control, vacuum system sequential control, steam generator cold salt salt filling sequential control, steam generator hot salt salt feeding sequential control, shaft seal system input sequential control, steam bypass system input sequential control, steam turbine start sequential control; The unit stop sequential control includes: steam turbine shutdown sequential control, mirror field stop sequential control, absorber desalting sequential control, cold salt pump stop sequential control, vacuum system stop sequential control, steam generator desalting sequential control, shaft seal system stop sequential control, auxiliary system stop sequential control; The molten salt pipeline is provided with molten salt pipeline electric tracing preheating sequential control; The steam generator is provided with steam generator water inlet temperature control sequential control, steam generator cold salt salt filling sequential control, steam generator hot salt salt feeding sequential control, and steam generator desalting sequential control; The steam bypass system is provided with steam bypass system input sequential control; The mirror field is provided with mirror field start sequential control and mirror field stop sequential control; The cold salt pump is provided with cold salt pump start sequential control and cold salt pump stop sequential control; The absorber tower is provided with absorber tower molten salt bypass salt filling sequential control, absorber main road salt filling sequential control, and absorber desalting sequential control; The vacuum system is provided with vacuum system sequential control and vacuum system stop sequential control; The shaft seal system is provided with shaft seal system input sequential control and shaft seal system stop sequential control; The steam turbine is equipped with a steam turbine startup sequence control and a steam turbine shutdown sequence control; The auxiliary system is equipped with an auxiliary system shutdown sequence control.

[0016] As can be seen from the above technical solutions, the present invention has the following advantages: In the one-key startup and shutdown control method for the tower-type solar thermal power station provided by this application, through the highly integrated one-key startup and shutdown function, the complex startup and shutdown operation processes are automated, reducing the operation burden of the operating personnel, reducing the risk of equipment damage caused by human errors, significantly improving the startup and shutdown efficiency of the power station, shortening the startup and shutdown time, and improving the overall operation efficiency of the power station.

[0017] The one-key startup and shutdown control system completes the startup and shutdown operations through preset automated programs. The operating personnel do not need to deeply understand the complex equipment startup and shutdown sequences, thereby reducing the training difficulty and cost and improving the operation proficiency of the operating personnel. Brief Description of the Drawings

[0018] In order to more clearly illustrate the technical solutions of the present invention, the drawings required for description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0019] Figure 1 It is a schematic diagram of the one-key startup process for the one-key startup and shutdown control method of the tower-type solar thermal power station; Figure 2 It is a schematic diagram of the one-key shutdown process for the one-key startup and shutdown control method of the tower-type solar thermal power station. Detailed Embodiments

[0020] In the following, the one-key startup and shutdown control method and system for the tower-type solar thermal power station will be described in detail, and various embodiments of the present disclosure will be described more comprehensively. The present disclosure can have various embodiments, and adjustments and changes can be made therein. However, it should be understood that there is no intention to limit the various embodiments of the present disclosure to the specific embodiments disclosed herein, but the present disclosure should be understood to cover all adjustments, equivalents, and / or alternative solutions falling within the spirit and scope of the various embodiments of the present disclosure.

[0021] Hereinafter, the term "comprising" or "may comprise" that may be used in various embodiments of the present disclosure indicates the presence of the disclosed functions, operations, or elements, and does not limit the addition of one or more functions, operations, or elements. In addition, as used in various embodiments of the present disclosure, the terms "comprising", "having", and their cognates are only intended to represent specific features, numbers, steps, operations, elements, components, or combinations of the foregoing items, and should not be construed as first excluding the existence of one or more other features, numbers, steps, operations, elements, components, or combinations of the foregoing items or the possibility of adding one or more features, numbers, steps, operations, elements, components, or combinations of the foregoing items.

[0022] Expressions (such as "first", "second", etc.) used in various embodiments of the present disclosure may modify various constituent elements in the various embodiments, but do not limit the corresponding constituent elements. For example, the above expressions do not limit the order and / or importance of the elements. The above expressions are only for the purpose of distinguishing one element from other elements. For example, the first user device and the second user device indicate different user devices, although both are user devices. For example, without departing from the scope of the various embodiments of the present disclosure, the first element may be referred to as the second element, and similarly, the second element may also be referred to as the first element.

[0023] It should be noted that: if it is described that one constituent element is "connected" to another constituent element, the first constituent element may be directly connected to the second constituent element, and a third constituent element may be "connected" between the first constituent element and the second constituent element. On the contrary, when one constituent element is "directly connected" to another constituent element, it can be understood that there is no third constituent element between the first constituent element and the second constituent element.

[0024] The term "user" used in various embodiments of the present disclosure may indicate a person who uses an electronic device, and may be a monitoring person, or a testing person, or an operator.

[0025] Hereinafter, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0026] The embodiments of the present application provide a one-key start-stop control method and system for a tower-type solar thermal power station, and solve the technical problems that there is an urgent need for a method to reduce the risk of equipment damage caused by human error and the training difficulty and cost of operating personnel.

[0027] Hereinafter, the technical solutions proposed in the embodiments of the present application will be described in detail with reference to the accompanying drawings.

[0028] The one-button start-stop control system of a tower-type CSP power plant includes unit start-up sequence control and unit stop sequence control. The tower-type CSP power plant starts and stops the main equipment and auxiliary systems of the entire plant through unit start-up sequence control and unit stop sequence control.

[0029] The unit start sequence control and unit stop sequence control are the core of the entire one-button start and stop control system, responsible for the overall start and stop process management and coordination, and defining the sequence and logic of the overall start and stop process. It controls the start and stop process of the entire power station according to the preset logic and sequence, monitors the start and stop status of the entire power station, and ensures that the system runs in the predetermined sequence. Provide a one-button start and stop user interface, receive operation instructions and trigger the entire start and stop process.

[0030] After the operator issues a one-button start command through the user interface, the command is first transmitted to the unit start sequence. According to the preset process logic, the unit start sequence sequentially mobilizes the molten salt pipeline electric tracing preheating sequence, steam generator water temperature control sequence, mirror field start sequence, cold salt pump start sequence, heat absorption tower molten salt bypass salt filling sequence, heat absorption main salt filling sequence, vacuum system sequence, steam generator cold salt filling sequence, steam generator hot salt filling sequence, shaft seal system start sequence, steam bypass system start sequence, and turbine start sequence.

[0031] After the operator issues a one-button stop command through the user interface, the command is first transmitted to the unit stop sequence. The unit stop sequence. The unit start sequence, according to the preset process logic, sequentially mobilizes the turbine shutdown sequence, mirror field stop sequence, absorber salt drainage sequence, cold salt pump stop sequence, vacuum system stop sequence, steam generator salt drainage sequence, shaft seal system stop sequence, and auxiliary system stop sequence.

[0032] The embodiment of the present application provides a one-button start-stop control method for a tower-type solar thermal power station, which specifically includes the following steps: Before starting, check in turn whether each auxiliary system has completed startup, whether the steam drum water filling is completed, whether the pipeline flushing is completed, whether the water quality is qualified, whether the turbine lubricating oil system is operating normally, and whether the turning is put into operation.

[0033] If all the above conditions are met, the molten salt pipeline electric tracing preheating sequence, steam generator water temperature control sequence, mirror field start sequence, cold salt pump start sequence, heat absorption tower molten salt bypass salt filling sequence, heat absorption main salt filling sequence, vacuum system sequence, steam generator cold salt filling sequence, steam generator hot salt filling sequence, shaft seal system start sequence, steam bypass system start sequence, and turbine start sequence are started in sequence.

[0034] Combination Figure 1, in this embodiment, starting the sequence control for preheating the molten salt pipeline specifically includes: starting the electric tracing heating system of the molten salt pipeline to heat the molten salt pipeline; setting the target temperature of the electric tracing heating to 290 °C, and setting the current electric tracing heating temperature command to be 20 °C higher than the current pipeline temperature; enabling temperature protection for the electric tracing heating. When the temperature rises to 290 °C, the electric tracing heating stops working. When the pipeline temperature drops to 270 °C, the electric tracing heating starts again to maintain the current molten salt pipeline temperature at 290 °C.

[0035] Starting the sequence control for controlling the water inlet temperature of the steam generator specifically includes: opening the inlet valve of the electric heater and the stop valve of the bypass electric valve of the water supply pipeline; after the drum liquid level reaches -200 mm, starting the preselected external circulation pump and the forced circulation pump to circulate, and putting the other two pumps in standby; gradually raising the frequency converter of the external circulation pump to the preset value, and at the same time starting the electric heater of the external circulation pump pipeline; when the water temperature is 5 °C higher than the molten salt condensation temperature, opening the main road electric valve of the water supply pipeline; after the main road electric valve of the water supply pipeline is fully opened, closing the bypass electric valve of the water supply pipeline.

[0036] Starting the sequence control for starting the mirror field specifically includes: when the DNI value measured by the meteorological system is greater than 200 W / m², the DCS sends a command to the mirror field control system to start the sequence control for starting the mirror field and turn on the mirror field preheating mode.

[0037] When the DNI reaches the standard, triggering the sequence control for starting the cold salt pump; when the mirror field has been started and the molten salt pipeline temperature exceeds the molten salt condensation point, starting the sequence control for starting the cold salt pump, which specifically includes: opening the cold salt pump recirculation valve to 50%; starting the preselected cold salt pump and opening the corresponding outlet valve; setting the motor frequency rise rate to 10% per minute and slowly increasing the motor frequency to 30% of the pump rated speed.

[0038] When the pipeline temperatures of the molten salt riser and downcomer in the receiver reach above the freezing point temperature, starting the sequence control for filling the molten salt bypass in the receiver tower. Starting the sequence control for filling the molten salt bypass in the receiver tower specifically includes: opening the bypass valve of the receiver tower; opening the start-up filling valve of the riser; opening the regulating valve at the outlet of the cold salt pump; adjusting the liquid level of the downcomer in the bypass mode; fully opening the regulating valve at the outlet of the salt pump.

[0039] When the outer screen temperature of the receiver, the back panel temperature, and the corresponding molten salt pipeline temperature exceed the molten salt condensation point, starting the sequence control for filling the main road of the receiver. Starting the sequence control for filling the main road of the receiver specifically includes: opening all the valves of the receiver; the liquid level of the charging inlet tank >2000 mm; closing the desalting valve of the inlet tank; charging the outlet tank, the liquid level > -2000 mm; closing the desalting valve of the tube bank; closing the exhaust valve of the tube bank; closing the bypass valve of the receiver.

[0040] Starting the mirror field power control mode specifically includes: after closing the bypass valve of the receiver, the mirror field enters the power mode, and gradually increasing the number of heliostats to increase the heating flow rate of the molten salt.

[0041] Start the sequence control of the vacuum system, specifically including: closing the vacuum break valve; fully opening the steam and condensate isolation valves; starting all vacuum pumps; confirming that the vacuum value reaches the unit requirement; stopping the standby vacuum pump; and putting the ACC automatic control into operation.

[0042] When the liquid level of the hot salt tank reaches one-fifth of the total range, start the sequence control of cold salt filling for the steam generator, specifically including: opening the vent valve of the cold salt molten salt pipeline to the atmosphere, closing the salt drainage valve; opening the recirculation regulating valve of the cold salt tank temperature control pump to the preset position to make the molten salt flow, and setting the valve to automatic control to control the outlet pressure of the pump; starting the preselected temperature control pump, setting the frequency converter command at the preset safe frequency, and opening the pump outlet valve; after the temperature control pump starts, delay for 10 seconds and then close the vent valve to the atmosphere; set the outlet regulating valve of the molten salt temperature control pipeline to 60%; increase the frequency of the temperature control pump to fill the molten salt at the head of the molten salt pipe of the steam generator; open the inlet valve of the molten salt pipeline of the reheater to 100% and set it to automatic control.

[0043] After the cold salt filling of the steam generator is completed and the liquid level of the hot salt tank reaches one-fourth of the total range, start the sequence control of hot salt feeding for the steam generator, specifically including: opening the vent valve of the hot salt pipeline to the atmosphere; opening the recirculation valve of the hot salt pump to the preset position to make the molten salt flow, and setting the valve to automatic control to control the outlet pressure of the pump; starting the preselected hot molten salt pump; after the hot salt pump starts, delay for 10 seconds and then close the vent valve to the atmosphere; set the outlet regulating valve of the hot salt pump to the automatic control state and set the current steam flow as the target value; according to the start-up curve rate of the steam generator, gradually increase the target value of the outlet regulating valve of the hot salt pump to the steam turbine demand flow.

[0044] After the sequence control of hot salt feeding is completed, start the sequence control of putting the shaft seal system into operation, specifically including: opening the auxiliary steam drain valve; when the steam temperature reaches the preset temperature and the steam pressure reaches the preset pressure, opening the auxiliary steam stop valve and regulating valve, and setting the control target value of the regulating valve to the shaft seal steam supply required pressure; putting the shaft seal electric heater into operation, setting the temperature to 420°C, and opening the drain valve after the heater; the shaft seal cooling fan is automatically put into operation and the fan is started; the desuperheating water solenoid valve of the main body drain expansion vessel is put into automatic opening; when the pressure and temperature in front of the shaft seal regulating valve reach the requirements, the spray water solenoid valve of the rear cylinder of the low-pressure cylinder is automatically put into operation; when the rear shaft seal pressure reaches the preset value, the shaft seal pressure control is automatically put into operation; the supply steam temperature of the rear shaft seal of the low-pressure cylinder is automatically put into operation; the drain valve in front of the shaft seal regulating valve is opened; after the shaft seal is put into operation, set the rear shaft seal pressure of the low-pressure cylinder to the shaft seal preset pressure and set the rear shaft seal temperature of the low-pressure cylinder to the shaft seal preset temperature.

[0045] Start the steam bypass system and put it into sequence control, specifically including: put the high-pressure bypass desuperheating water valve, low-pressure bypass desuperheating water valve, and tertiary desuperheating water valve into the automatic state, set the control target value of the high-pressure bypass desuperheating water valve to the preset required temperature of the hot reheater, set the control target value of the low-pressure bypass desuperheating water valve to the preset required temperature of the air-cooled pipeline and the steam turbine, and set the control target value of the tertiary desuperheating water valve to the preset required temperature of the air-cooled system; set the minimum valve position of the high-pressure steam bypass valve and the low-pressure steam bypass valve to 10%; put the high-pressure steam bypass valve and the low-pressure steam bypass valve into the automatic control state, and set the pressure control target value of the high-pressure steam bypass valve and the low-pressure steam bypass valve to the preset required pressure of the steam turbine.

[0046] Start the steam turbine startup sequence control, specifically including: after the steam pressure and temperature in the steam generator reach the unit startup conditions, trigger the steam turbine startup sequence control until the steam turbine reaches full speed and no-load.

[0047] Combined with Figure 2 , the unit load has been reduced to the minimum load of the unit according to the grid requirements. Start the steam turbine shutdown sequence control, specifically including: trigger the unit shutdown signal to the steam turbine.

[0048] Stop the mirror field sequence control, specifically including: the DCS sends a command to the mirror field control system to gradually reduce the number of focusing heliostats.

[0049] When the molten salt temperature drop in the absorber is equal to the condensation point temperature plus 30 degrees, the absorber salt drainage sequence control step starts. Start the absorber salt drainage sequence control, specifically including: close the rising pipe regulating valve and the cold salt pump outlet regulating valve; close the pipe screen inlet regulating valve; open the pipe screen salt drainage valve to control the inlet tank pressure; open the pipe screen salt drainage valve and the inlet tank salt drainage valve; control the inlet tank pressure at 0.5 bar; open the rising pipe, screen inlet regulating valve and the absorber bypass valve; after the salt drainage is completed, set the inlet tank pressure to -2 bar. After the salt drainage is completed, maintain the preheating mode to gradually cool down the absorber.

[0050] After the cold salt pump outlet regulating valve is closed, start the cold salt pump stop sequence control, specifically including: slowly reduce the output of the cold salt pump to 30%; stop all cold salt pumps and close the outlet valves.

[0051] When the steam turbine speed reaches zero and the turning gear is put into operation, trigger the vacuum system stop sequence control. Start the vacuum system stop sequence control, specifically including: stop all vacuum pumps; stop the air-cooled system; open the vacuum break valve.

[0052] When the steam turbine speed reaches zero and the turning gear is put into operation, start the steam generator salt drainage sequence control. Start the steam generator salt drainage sequence control, specifically including: stop all temperature control pumps, close the pump outlet valves and the recirculation regulating valves; stop all hot salt pumps, close the pump outlet valves and the recirculation regulating valves; open the salt drainage valve and the exhaust valve.

[0053] After the vacuum system stops, the sequence control for the shaft sealing system stops, and the sequence control for starting the shaft sealing system stop is initiated, specifically including: when the vacuum is completely zero, close the shaft sealing steam supply valve; fully close the shaft sealing steam supply regulating valve; close the desuperheating water regulating valve; stop the shaft sealing cooler fan.

[0054] After the shaft seal is withdrawn, initiate the sequence control for stopping the auxiliary system, specifically including: after the shaft seal is withdrawn, the auxiliary system is stopped by sequence control.

[0055] The one-key start-stop control system for the tower-type solar thermal power station greatly simplifies the operation process of the power station, enabling the staff to complete the start-up or stop process of the entire power station through simple operations. It reduces the possibility of human operation errors, improves the accuracy and reliability of operations. It reduces the dependence on manual operations, thereby reducing labor costs. By reducing the probability of misoperations and failures, the maintenance and repair costs are reduced.

[0056] The present invention also provides a one-key start-stop control system for a tower-type solar thermal power station, and the system includes a unit, a unit start sequence control, and a unit stop sequence control; the tower-type solar thermal power station completes the start and stop of the unit through the unit start sequence control and the unit stop sequence control.

[0057] The unit start sequence control includes: the molten salt pipeline electric tracing preheating sequence control, the steam generator water filling temperature control sequence control, the mirror field start sequence control, the cold salt pump start sequence control, the molten salt bypass filling sequence control for the heat absorption tower, the main path salt filling sequence control for the heat absorber, the vacuum system sequence control, the cold salt filling sequence control for the steam generator, the hot salt feeding sequence control for the steam generator, the shaft sealing system input sequence control, the steam bypass system input sequence control, and the steam turbine start sequence control.

[0058] The unit stop sequence control includes: the steam turbine shutdown sequence control, the mirror field stop sequence control, the heat absorber salt draining sequence control, the cold salt pump stop sequence control, the vacuum system stop sequence control, the steam generator salt draining sequence control, the shaft sealing system stop sequence control, and the auxiliary system stop sequence control.

[0059] The molten salt pipeline is provided with the molten salt pipeline electric tracing preheating sequence control; the steam generator is provided with the steam generator water filling temperature control sequence control, the cold salt filling sequence control for the steam generator, the hot salt feeding sequence control for the steam generator, and the steam generator salt draining sequence control; the steam bypass system is provided with the steam bypass system input sequence control; the mirror field is provided with the mirror field start sequence control and the mirror field stop sequence control; the cold salt pump is provided with the cold salt pump start sequence control and the cold salt pump stop sequence control; the heat absorption tower is provided with the molten salt bypass filling sequence control for the heat absorption tower, the main path salt filling sequence control for the heat absorber, and the heat absorber salt draining sequence control; the vacuum system is provided with the vacuum system sequence control and the vacuum system stop sequence control; the shaft sealing system is provided with the shaft sealing system input sequence control and the shaft sealing system stop sequence control; the steam turbine is provided with the steam turbine start sequence control and the steam turbine shutdown sequence control; the auxiliary system is provided with the auxiliary system stop sequence control.

[0060] The unit startup sequence control calls the molten salt pipeline electric tracing preheating sequence control, the steam generator water inlet temperature control sequence control, the mirror field startup sequence control, the cold salt pump startup sequence control, the molten salt bypass filling sequence control of the heat absorption tower, the main path filling sequence control of the heat absorber, the vacuum system sequence control, the cold salt filling sequence control of the steam generator, the hot salt feeding sequence control of the steam generator, the shaft seal system startup sequence control, the steam bypass system startup sequence control and the steam turbine startup sequence control to complete the unit startup process and finally realize the full speed no-load operation of the steam turbine.

[0061] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0062] For those of ordinary skill in the art, designing different forms of control circuits does not require creative labor according to the teachings of the present invention. These changes, modifications, substitutions, and variations to the embodiments still fall within the protection scope of the present invention without departing from the principles and spirit of the present invention.

Claims

1. A one-key start-stop control method for a tower-type solar thermal power station, characterized in that, The method includes: At startup, sequentially start the electric tracing preheating sequence control of the molten salt pipeline, the water inlet temperature control sequence control of the steam generator, the heliostat field startup sequence control, the cold salt pump startup sequence control, the molten salt bypass filling sequence control of the absorber tower, the main path filling sequence control of the absorber, the vacuum system sequence control, the cold salt filling sequence control of the steam generator, the hot salt feeding sequence control of the steam generator, the shaft sealing system input sequence control, the steam bypass system input sequence control, and the steam turbine startup sequence control; At shutdown, sequentially start the steam turbine shutdown sequence control, the heliostat field shutdown sequence control, the absorber salt draining sequence control, the cold salt pump shutdown sequence control, the vacuum system shutdown sequence control, the steam generator salt draining sequence control, the shaft sealing system shutdown sequence control, and the auxiliary system shutdown sequence control.

2. The one-key start-stop control method according to claim 1, characterized in that, Starting the electric tracing preheating sequence control of the molten salt pipeline specifically includes: Step S11: Start the electric tracing system of the molten salt pipeline to heat the molten salt pipeline; Step S12: Set the target temperature of the electric tracing to 290 °C, and set the current electric tracing temperature command to be 20 °C higher than the current pipeline temperature; Step S13: The electric tracing is provided with temperature protection. When the temperature rises to 290 °C, the electric tracing stops working. When the pipeline temperature drops to 270 °C, the electric tracing starts again to keep the current molten salt pipeline temperature at 290 °C; Starting the water inlet temperature control sequence control of the steam generator specifically includes: Step S21: Open the inlet door of the electric heater and the stop valve of the bypass electric valve of the water supply pipeline; Step S22: After the drum liquid level reaches -200 mm, start the preselected external circulation pump and the forced circulation pump to circulate, and put the other two pumps in standby; Step S23: Gradually raise the frequency converter of the external circulation pump to the preset value, and at the same time start the electric heater of the external circulation pump pipeline; Step S24: When the water temperature is 5 °C higher than the molten salt condensation temperature, open the main path electric valve of the water supply pipeline; Step S25: After the main path electric valve of the water supply pipeline is fully opened, close the bypass electric valve of the water supply pipeline; Starting the heliostat field startup sequence control specifically includes: When the DNI value measured by the meteorological system is greater than 200 W / m², the DCS sends a command to the heliostat field control system to start the heliostat field startup sequence control and turn on the heliostat field preheating mode.

3. The one-key start-stop control method according to claim 2, characterized in that, When the heliostat field has been started and the molten salt pipeline temperature exceeds the molten salt condensation point, start the cold salt pump startup sequence control, specifically including: Step S31: Open the cold salt pump recirculation valve to 50%; Step S32: Start the preselected cold salt pump and open the corresponding outlet valve; Step S33: Set the motor frequency rise rate to 10% per minute, and slowly increase the motor frequency to 30% of the pump rated speed; When the pipeline temperatures of the molten salt riser and downcomer of the absorber reach above the freezing point, start the molten salt bypass filling sequence control of the absorber tower, specifically including: Step S41: Open the bypass valve of the absorber tower; Step S42: Open the startup filling valve of the riser; Step S43: Open the outlet regulating valve of the cold salt pump; Step S44: Adjust the downcomer liquid level in the bypass mode; Step S45: Fully open the outlet regulating valve of the salt pump.

4. The one-key start-stop control method according to claim 3, wherein When the outer screen temperature, the back panel temperature of the absorber, and the corresponding molten salt pipeline temperature exceed the molten salt condensation point, start the main path filling sequence control of the absorber, specifically including: Step S51: Open all valves of the absorber; Step S52: The liquid level of the charging inlet tank > 2000 mm; Step S53: Close the desalting valve of the inlet tank; Step S54: Fill the outlet tank until the liquid level > -2000 mm; Step S55: Close the desalting valve of the tube screen; Step S56: Close the vent valve of the tube screen; Step S57: Close the bypass valve of the absorber; Start the mirror field power control mode, specifically including: after closing the bypass valve of the absorber, the mirror field enters the power mode, and gradually increase the number of heliostats to increase the heating flow rate of the molten salt; Start the sequence control of the vacuum system, specifically including: Step S61: Close the vacuum break valve; Step S62: Fully open the steam and condensate isolation valve; Step S63: Start all vacuum pumps; Step S64: Confirm that the vacuum value reaches the unit requirement; Step S65: Stop the standby vacuum pump; Step S66: Put the ACC automatic control into operation.

5. The one-key start-stop control method according to claim 4, wherein, When the hot salt tank liquid level reaches one-fifth of the total range, start the cold salt filling sequence control of the steam generator, specifically including: Step S71: Open the vent valve of the cold salt molten salt pipeline to the atmosphere, and close the desalting valve; Step S72: Open the recirculation regulating valve of the cold salt tank temperature control pump to the preset position to make the molten salt flow, and set the valve to automatic control to control the outlet pressure of the pump; Step S73: Start the preselected temperature control pump, set the frequency converter command at the preset safe frequency, and open the pump outlet valve; Step S74: After the temperature control pump starts, delay for 10 seconds and close the vent valve to the atmosphere; Step S75: Set the outlet regulating valve of the molten salt temperature control pipeline to 60%; Step S76: Increase the frequency of the temperature control pump to fill the molten salt pipe head of the steam generator with molten salt; Step S77: Open the inlet valve of the molten salt pipeline of the reheater to 100% and set it to automatic control; When the cold salt filling of the steam generator ends and the hot salt tank liquid level reaches one-fourth of the total range, start the hot salt feeding sequence control of the steam generator, specifically including: Step S81: Open the vent valve of the hot salt pipeline to the atmosphere; Step S82: Open the recirculation valve of the hot salt pump to the preset position to make the molten salt flow, and set the valve to automatic control to control the outlet pressure of the pump; Step S83: Start the preselected hot molten salt pump; Step S84: After the hot salt pump starts, delay for 10 seconds and close the vent valve to the atmosphere; Step S85: Set the outlet regulating valve of the hot salt pump to the automatic control state and set the current steam flow as the target value; Step S86: Gradually increase the target value of the outlet regulating valve of the hot salt pump to the steam turbine demand flow rate according to the start-up curve rate of the steam generator.

6. The one-key start-stop control method according to claim 5, characterized in that, After the hot salt feeding sequence control ends, start the sequence control of putting the shaft seal system into operation, specifically including: Step S91: Open the auxiliary steam drain valve; Step S92: When the steam temperature reaches the preset temperature and the steam pressure reaches the preset pressure, open the auxiliary steam stop valve and regulating valve, and set the control target value of the regulating valve to the shaft seal steam supply required pressure; Step S93: Put the shaft seal electric heater into operation, set the temperature to 420 °C, and open the drain valve after the heater; Step S94: The shaft seal cooling fan is automatically put into operation and start the fan; Step S95: The desuperheating water solenoid valve of the main body drain expansion vessel is automatically put into operation and opened; Step S96: When the pressure and temperature in front of the shaft seal regulating valve reach the requirements, put the low-pressure cylinder rear cylinder spray water solenoid valve into automatic operation; Step S97: When the rear shaft seal pressure reaches the preset value, the shaft seal pressure control is automatically put into operation; Step S98: Automatically input the supply steam temperature of the rear shaft seal of the low-pressure cylinder; Step S99: Open the drain valve in front of the shaft seal regulating valve; Step S910: After the shaft seal is put into operation, set the pressure of the rear shaft seal of the low-pressure cylinder to the preset shaft seal pressure, and set the temperature of the rear shaft seal of the low-pressure cylinder to the preset shaft seal temperature.

7. The one-key start-stop control method according to claim 6, wherein Start the steam bypass system and input the sequence control, specifically including: Step S101: Put the high-pressure bypass desuperheating water valve, low-pressure bypass desuperheating water valve and tertiary desuperheating water valve into the automatic state, set the control target value of the high-pressure bypass desuperheating water valve to the preset required temperature of the hot reheater, set the control target value of the low-pressure bypass desuperheating water valve to the preset required temperature of the air-cooled pipeline and the steam turbine, and set the control target value of the tertiary desuperheating water valve to the preset required temperature of the air-cooled system; Step S102: Set the minimum valve position of the high-pressure steam bypass valve and the low-pressure steam bypass valve to 10%; Step S103: Put the high-pressure steam bypass valve and the low-pressure steam bypass valve into the automatic control state, and set the pressure control target value of the high-pressure steam bypass valve and the low-pressure steam bypass valve to the preset required pressure of the steam turbine; Start the steam turbine startup sequence control, specifically including: After the steam pressure and temperature in the steam generator reach the unit startup conditions, trigger the steam turbine startup sequence control until the steam turbine reaches full speed and no-load.

8. The one-key start-stop control method according to claim 7, characterized in that, When the unit shutdown sequence control starts, when the unit load has been reduced to the minimum unit load according to the requirements of the power grid dispatching, start the steam turbine shutdown sequence control, specifically including: trigger the unit shutdown signal to the steam turbine; The heliostat field stop sequence control, specifically including: The DCS sends instructions to the heliostat field control system to gradually reduce the number of focusing heliostats; When the molten salt temperature drop in the receiver is equal to the condensation point temperature plus 30 degrees, start the receiver salt drainage sequence control, specifically including: Step S111: Close the rising pipe regulating valve and the outlet regulating valve of the cold salt pump; Step S112: Close the inlet regulating valve of the tube bank; Step S113: Open the tube bank salt drainage valve to control the inlet tank pressure; Step S114: Open the tube bank salt drainage valve and the inlet tank salt drainage valve; Step S115: Control the inlet tank pressure at 0.5 bar; Step S116: Open the rising pipe, the inlet regulating valve of the tube bank and the receiver bypass valve; Step S117: After the salt drainage is completed, set the inlet tank pressure to -2 bar. After the salt drainage is completed, maintain the preheating mode to gradually cool down the receiver; After the outlet regulating valve of the cold salt pump is closed, start the cold salt pump stop sequence control, specifically including: Step S121: Slowly reduce the output of the cold salt pump to 30%; Step S122: Stop all cold salt pumps and close the outlet valves.

9. The one-key start-stop control method according to claim 8, wherein When the steam turbine speed reaches zero and the turning gear is put into operation, start the vacuum system stop sequence control, specifically including: Step S131: Stop all vacuum pumps; Step S132: Stop the air-cooled system; Step S133: Open the vacuum break valve; When the steam turbine speed reaches zero and the turning gear is put into operation, start the steam generator salt drainage sequence control, specifically including: Step S141: Stop all temperature regulating pumps, and close the pump outlet valves and the recirculation regulating valves; Step S142: Stop all hot salt pumps, and close the pump outlet valves and the recirculation regulating valves; Step S143: Open the salt drainage valve and the exhaust valve; After the vacuum system stop sequence control is completed, start the shaft seal system stop sequence control, specifically including: Step S151: When the vacuum completely reaches zero, close the shaft sealing steam valve. Step S152: Completely close the shaft sealing steam regulating valve. Step S153: Close the desuperheating water regulating valve. Step S154: Stop the shaft sealing cooler fan. When the shaft sealing is withdrawn, start the sequence control for stopping the auxiliary system, specifically including: when the shaft sealing is withdrawn, the sequence control stops the auxiliary system.

10. One - key start - stop control system applied to the one - key start - stop control method of the tower - type solar thermal power station according to any one of claims 1 - 9, characterized in that, The system includes a unit, a unit start sequence control, and a unit stop sequence control. The unit includes: a molten salt pipeline, a steam generator, a heliostat field, a cold salt system, a hot salt system, a heat absorption tower, a vacuum system, a shaft sealing system, a steam bypass system, a steam turbine, and an auxiliary system. The unit start sequence control includes: a molten salt pipeline electric tracing preheating sequence control, a steam generator feed water temperature control sequence control, a heliostat field start sequence control, a cold salt pump start sequence control, a molten salt bypass filling sequence control for the heat absorption tower, a main path filling sequence control for the heat absorber, a vacuum system sequence control, a cold salt filling sequence control for the steam generator, a hot salt feeding sequence control for the steam generator, a shaft sealing system input sequence control, a steam bypass system input sequence control, and a steam turbine start sequence control. The unit stop sequence control includes: a steam turbine shutdown sequence control, a heliostat field stop sequence control, a heat absorber salt draining sequence control, a cold salt pump stop sequence control, a vacuum system stop sequence control, a steam generator salt draining sequence control, a shaft sealing system stop sequence control, and an auxiliary system stop sequence control. The molten salt pipeline is equipped with a molten salt pipeline electric tracing preheating sequence control. The steam generator is equipped with a steam generator feed water temperature control sequence control, a cold salt filling sequence control for the steam generator, a hot salt feeding sequence control for the steam generator, and a steam generator salt draining sequence control. The steam bypass system is equipped with a steam bypass system input sequence control. The heliostat field is equipped with a heliostat field start sequence control and a heliostat field stop sequence control. The cold salt pump is equipped with a cold salt pump start sequence control and a cold salt pump stop sequence control. The heat absorption tower is equipped with a molten salt bypass filling sequence control for the heat absorption tower, a main path filling sequence control for the heat absorber, and a heat absorber salt draining sequence control. The vacuum system is equipped with a vacuum system sequence control and a vacuum system stop sequence control. The shaft sealing system is equipped with a shaft sealing system input sequence control and a shaft sealing system stop sequence control. The steam turbine is equipped with a steam turbine start sequence control and a steam turbine shutdown sequence control. The auxiliary system is equipped with an auxiliary system stop sequence control.

Images