A back pressure turbine steam supply wide load operation control method and system under deep regulation working condition

Abstract

This invention proposes a method and system for controlling the operation of a back-pressure turbine under deep-load conditions with wide-load steam supply. The exhaust outlet of the back-pressure turbine is connected to the user end via the main exhaust pipeline. An exhaust regulating valve and an exhaust branch pipeline are added at the exhaust outlet. The first outlet of the exhaust regulating valve is connected to the user end via the main exhaust pipeline, and the second outlet of the exhaust regulating valve is connected to the deaerator system via the exhaust branch pipeline. The control method includes: acquiring real-time operating data of the back-pressure turbine, boiler load, and deaerator pressure under low-load conditions; calculating the minimum inlet steam flow and minimum active power of the back-pressure turbine based on the factory design parameters; controlling the steam flow on the inlet side of the back-pressure turbine to the minimum inlet steam flow and operating according to the minimum active power based on the operating data; controlling the exhaust regulating valve to only connect the pipeline between the back-pressure turbine and the deaerator system; calculating the differential pressure based on the operating data for back-pressure turbine protection; determining the exhaust pressure setpoint based on the boiler load and deaerator pressure, and controlling the exhaust pressure to the exhaust pressure setpoint.

Description

Technical Field

[0001] This invention belongs to the field of steam turbine control technology, and particularly relates to a method and system for controlling the operation of back pressure turbine steam supply under deep adjustment conditions and wide load. Background Technology

[0002] With the continuous improvement of my country's industrialization level, industrial agglomeration and zone management have become important characteristics of local industrial economic development, which has spurred a strong demand for industrial heating from industrial park enterprises. At the same time, the state and various regions require that the steam required in the industrial production process be solved as much as possible by using centralized industrial steam supply from power plants.

[0003] Currently, industrial steam supply methods mainly include: reheat extraction, high and low pressure bypass steam supply, back pressure turbine utilization, and steam extracted from the secondary loop of nuclear power units as a heat source for multi-stage heat exchange before supplying heat. Among these, equipping with a back pressure turbine is an important industrial heating method. The general principle for selecting a back pressure turbine is: for stable heat users with annual heat demand exceeding 6000 hours and only one parameter, back pressure units are the most ideal choice. Therefore, they are widely used in chemical, papermaking, and other enterprises as units with basic heat load or as units for industrial surplus pressure power generation. The "Notice on Issuing the Management Measures for Cogeneration" (NDRC Energy

[2016] No. 617) clearly stipulates that: in the Beijing-Tianjin-Hebei region, the Yangtze River Delta, and the Pearl River Delta, planned industrial cogeneration projects should prioritize the use of gas-fired units; coal-fired cogeneration projects must use back pressure units, and the policy of equal or reduced coal substitution must be strictly implemented; and "industrial cogeneration projects should prioritize the use of high-pressure and above parameter back pressure cogeneration units."

[0004] The model of large power generation enterprises providing centralized industrial steam supply to enterprises in surrounding industrial parks has developed rapidly. With regional economic development, the demand for industrial steam supply is gradually increasing. However, against the backdrop of carbon peaking and carbon neutrality, the installed capacity of renewable energy sources such as wind and solar power is increasing, and the amount of electricity transmitted across regions and provinces is growing rapidly. To ensure the safe and stable operation of the power grid, thermal power units need to participate in deep peak shaving and operate under medium / low load conditions. In actual operation, there are instances where the back-pressure turbine cannot operate continuously under low load conditions, including: excessively low back-pressure turbine inlet steam pressure, back-pressure turbine exhaust steam failing to meet industrial steam supply parameter requirements, and the risk of boiler reheater overheating. Therefore, when participating in deep peak shaving, frequent start-up and shutdown of the back-pressure turbine are necessary, resulting in significant waste of working fluid and heat loss, jeopardizing the lifespan of the back-pressure turbine, and posing safety risks to the unit's operation. Summary of the Invention

[0005] This invention aims to at least partially solve one of the technical problems in the related art. To this end, this invention provides a method and system for controlling the wide-load operation of back-compressor steam supply under deep-adjustment conditions, with the main objective of improving the wide-load operation capability of back-compressor industrial steam supply under deep-adjustment conditions, thereby reducing the frequency of back-compressor start-up and shutdown.

[0006] According to a first aspect of the present invention, a method for controlling the operation of a back-pressure turbine under deep-adjustment conditions with wide-load steam supply is provided. The exhaust outlet of the back-pressure turbine is connected to the user end via a main exhaust pipeline. An exhaust regulating valve and an exhaust branch pipeline are added at the exhaust outlet. The inlet of the exhaust regulating valve is connected to the exhaust outlet of the back-pressure turbine via the main exhaust pipeline. The first outlet of the exhaust regulating valve is connected to the user end via the main exhaust pipeline. The second outlet of the exhaust regulating valve is connected to the deaerator system via the exhaust branch pipeline. The control method includes:

[0007] When the back pressure unit is under low load, the operating data of the back pressure unit, boiler load and deaerator pressure are acquired in real time.

[0008] Calculate the minimum steam inlet flow and minimum active power of the back pressure unit based on the factory design parameters;

[0009] Based on the factory design parameters and the operating data, the steam flow rate on the steam inlet side of the back pressure unit is controlled to be the minimum steam inlet flow rate, and the back pressure unit is controlled to operate according to the minimum active power value.

[0010] Control the exhaust regulating valve to connect the exhaust outlet of the back pressure unit to the deaerator system, and disconnect the exhaust outlet from the user terminal.

[0011] The differential pressure is calculated based on the operating data, and back pressure protection is performed based on the differential pressure and differential pressure threshold.

[0012] The exhaust pressure setpoint is determined based on the boiler load and the deaerator pressure, and the exhaust pressure of the back pressure compressor is controlled to be the exhaust pressure setpoint.

[0013] In the back-pressure compressor steam supply wide-load operation control method provided in the first aspect of the present invention, the back-pressure compressor includes a high-temperature low-pressure steam inlet branch, a high-pressure low-temperature steam inlet branch, and a main steam inlet branch. The high-temperature low-pressure steam inlet branch and the high-pressure low-temperature steam inlet branch are respectively connected to the steam inlet of the back-pressure compressor via the main steam inlet branch. A first steam inlet regulating valve is provided on the high-temperature low-pressure steam inlet branch, a second steam inlet regulating valve is provided on the high-pressure low-temperature steam inlet branch, and a third steam inlet regulating valve is provided on the main steam inlet branch. The step of controlling the steam flow rate of the back-pressure compressor steam inlet side to the minimum steam inlet flow rate based on the factory design parameters and the operating data includes: acquiring steam parameter data of cold reheat, hot reheat, and first-stage extraction; adjusting the first steam inlet regulating valve and the second steam inlet regulating valve based on the factory design parameters, the operating data, and the steam parameter data to make the steam temperature in the main steam inlet branch a set temperature and the steam pressure a set pressure; and adjusting the third steam inlet regulating valve to make the steam flow rate at the inlet of the back-pressure compressor the minimum steam inlet flow rate.

[0014] In the back-compressor steam supply wide-load operation control method provided in the first aspect of the present invention under deep adjustment conditions, the operating data includes the back-compressor wheel chamber pressure and the back-compressor exhaust pressure, and the differential pressure is calculated based on the back-compressor wheel chamber pressure and the exhaust pressure.

[0015] In the back-pressure turbine steam supply wide-load operation control method provided in the first aspect of the present invention, the differential pressure threshold includes a first differential pressure threshold and a second differential pressure threshold, wherein the first differential pressure threshold is greater than the second differential pressure threshold, and the back-pressure turbine protection based on the differential pressure and the differential pressure threshold includes: if the differential pressure is greater than or equal to the first differential pressure threshold, then delaying for a first preset time, and then triggering the back-pressure turbine trip protection; if the differential pressure is less than the first differential pressure threshold but greater than or equal to the second differential pressure threshold, then issuing an alarm reminder, and simultaneously closing the first steam inlet regulating valve and the second steam inlet regulating valve at a set rate until the differential pressure drops to a preset proportion of the second differential pressure threshold.

[0016] The back-pressure turbine steam supply wide-load operation control method under deep adjustment conditions provided in the first aspect of the present invention further includes obtaining the deaerator water level and performing back-pressure turbine trip protection based on the deaerator water level and the deaerator water level threshold.

[0017] In the back-compressor steam supply wide-load operation control method under deep adjustment conditions provided in the first aspect of the present invention, the back-compressor protection based on the deaerator water level and the deaerator water level threshold includes: if the deaerator water level is greater than or equal to the deaerator water level threshold, then delay for a second preset time, and then trigger the back-compressor trip protection.

[0018] In the back-pressure turbine steam supply wide-load operation control method provided in the first aspect of the present invention, the step of determining the exhaust pressure setpoint based on the boiler load and the deaerator pressure includes: acquiring historical data, the historical data including various boiler loads, various deaerator pressures, and various exhaust pressure change rates; obtaining exhaust pressure setpoint function relationships corresponding to different exhaust pressure change rates based on different boiler loads and different deaerator pressures; inputting the set exhaust pressure change rate; selecting a target exhaust pressure setpoint function relationship from each exhaust pressure setpoint function relationship; and obtaining the exhaust pressure setpoint based on the target exhaust pressure setpoint function relationship, the real-time acquired boiler load, and the deaerator pressure.

[0019] The back-pressure turbine steam supply wide-load operation control method under deep adjustment conditions provided in the first aspect of the present invention further includes: calculating the maximum steam inlet flow rate and the maximum active power of the back-pressure turbine based on the factory design parameters; and performing a safety check based on the maximum steam inlet flow rate, minimum steam inlet flow rate, maximum active power, and minimum active power.

[0020] According to a second aspect of the present invention, a back-pressure turbine steam supply wide-load operation control system under deep-adjustment conditions is also provided, comprising:

[0021] The acquisition module is used to acquire real-time operating data of the back pressure unit, boiler load, and deaerator pressure when the back pressure unit is under low load conditions.

[0022] The verification calculation module is used to calculate the minimum inlet steam flow and minimum active power of the back pressure unit based on the factory design parameters.

[0023] The steam inlet control module is used to control the steam flow rate on the steam inlet side of the back pressure unit to the minimum steam inlet flow rate based on the factory design parameters and the operating data, and to control the back pressure unit to operate according to the minimum active power value.

[0024] The exhaust module includes an exhaust regulating valve, an exhaust branch pipeline, and a deaerator system. The inlet of the exhaust regulating valve is connected to the exhaust outlet of the back pressure unit via the exhaust main pipeline. The first outlet of the exhaust regulating valve is connected to the user end via the exhaust main pipeline. The second outlet of the exhaust regulating valve is connected to the deaerator system via the exhaust branch pipeline.

[0025] The heating control module is used to control the exhaust regulating valve so that the pipeline between the exhaust outlet of the back pressure unit and the deaerator system is connected, and the pipeline between the exhaust outlet and the user terminal is closed.

[0026] The protection setting module is used to calculate the differential pressure based on the operating data, and to perform back pressure protection based on the differential pressure and differential pressure threshold.

[0027] The exhaust control module is used to determine the exhaust pressure setpoint based on the boiler load and the deaerator pressure, and control the exhaust pressure of the back pressure unit to be the exhaust pressure setpoint.

[0028] In the back-pressure turbine steam supply wide-load operation control system provided in the second aspect of the present invention, the back-pressure turbine includes a high-temperature low-pressure steam inlet branch, a high-pressure low-temperature steam inlet branch, and a main steam inlet. The high-temperature low-pressure steam inlet branch and the high-pressure low-temperature steam inlet branch are respectively connected to the steam inlet of the back-pressure turbine via the main steam inlet. A first steam inlet regulating valve is provided on the high-temperature low-pressure steam inlet branch, a second steam inlet regulating valve is provided on the high-pressure low-temperature steam inlet branch, and a third steam inlet regulating valve is provided on the main steam inlet. The steam inlet control module is specifically used for: acquiring steam parameter data of cold reheat, hot reheat, and first-stage extraction; adjusting the first steam inlet regulating valve and the second steam inlet regulating valve based on the factory design parameters, the operating data, and the steam parameter data, so that the steam temperature in the main steam inlet is a set temperature and the steam pressure is a set pressure; and adjusting the third steam inlet regulating valve so that the steam flow rate at the inlet of the back-pressure turbine is the minimum steam flow rate.

[0029] In the back-compressor steam supply wide-load operation control system under deep adjustment conditions provided in the second aspect of the present invention, the operating data includes the back-compressor wheel chamber pressure and the back-compressor exhaust pressure. The protection setting module is specifically used to calculate the differential pressure based on the back-compressor wheel chamber pressure and the exhaust pressure.

[0030] In the back-pressure turbine steam supply wide-load operation control system provided in the second aspect of the present invention, the differential pressure threshold includes a first differential pressure threshold and a second differential pressure threshold, wherein the first differential pressure threshold is greater than the second differential pressure threshold. The protection setting module is specifically used for: if the differential pressure is greater than or equal to the first differential pressure threshold, then delaying for a first preset time, and then triggering the back-pressure turbine trip protection; if the differential pressure is less than the first differential pressure threshold but greater than or equal to the second differential pressure threshold, then issuing an alarm reminder, and simultaneously closing the first steam inlet regulating valve and the second steam inlet regulating valve at a set rate until the differential pressure drops to a preset proportion of the second differential pressure threshold.

[0031] In the back-pressure turbine steam supply wide-load operation control system provided in the second aspect of the present invention, the acquisition module is further used to acquire the deaerator water level, and the protection setting module is further used to: perform back-pressure turbine trip protection based on the deaerator water level and the deaerator water level threshold.

[0032] In the back-pressure turbine steam supply wide-load operation control system provided in the second aspect of the present invention, the protection setting module is specifically used to: if the deaerator water level is greater than or equal to the deaerator water level threshold, delay for a second preset time, and then trigger the back-pressure turbine trip protection.

[0033] In the back-pressure turbine steam supply wide-load operation control system under deep-adjustment conditions provided in the second aspect of the present invention, the exhaust steam control module is specifically used for: acquiring historical data, the historical data including various boiler loads, various deaerator pressures, and various exhaust steam pressure change rates; obtaining exhaust steam pressure setting function relationships corresponding to different exhaust steam pressure change rates based on different boiler loads and different deaerator pressures; inputting the set exhaust steam pressure change rate; selecting a target exhaust steam pressure setting function relationship from each exhaust steam pressure setting function relationship; and obtaining the exhaust steam pressure setting value based on the target exhaust steam pressure setting function relationship, the real-time acquired boiler load, and deaerator pressure.

[0034] In the back-pressure turbine steam supply wide-load operation control system provided in the second aspect of the present invention, the verification calculation module is further used to calculate the maximum steam inlet flow and maximum active power of the back-pressure turbine based on the factory design parameters; and to perform safety verification based on the maximum steam inlet flow, minimum steam inlet flow, maximum active power and minimum active power.

[0035] According to a third aspect of the present invention, a back-pressure turbine steam supply wide-load operation control device under deep-adjustment conditions is also provided, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to execute the back-pressure turbine steam supply wide-load operation control method under deep-adjustment conditions proposed in the first aspect of the present invention.

[0036] In one or more aspects of the present invention, the exhaust outlet of the back pressure turbine is connected to the user end via a main exhaust pipeline. An exhaust regulating valve and an exhaust branch pipeline are added at the exhaust outlet. The inlet of the exhaust regulating valve is connected to the exhaust outlet of the back pressure turbine via the main exhaust pipeline. The first outlet of the exhaust regulating valve is connected to the user end via the main exhaust pipeline. The second outlet of the exhaust regulating valve is connected to the deaerator system via the exhaust branch pipeline. The control method includes: when the back pressure turbine is under low load conditions, real-time acquisition of the back pressure turbine's factory design parameters and operating data, as well as the boiler load and deaerator pressure; based on the factory design parameters... The system calculates the minimum inlet steam flow and minimum active power of the back pressure turbine; based on the factory design parameters and operating data, it controls the steam flow on the inlet side of the back pressure turbine to the minimum inlet steam flow and controls the back pressure turbine to operate at the minimum active power; it controls the exhaust regulating valve to connect the pipeline between the exhaust outlet of the back pressure turbine and the deaerator system, and to close the pipeline between the exhaust outlet and the user end; it calculates the differential pressure based on the operating data, and performs back pressure turbine protection based on the differential pressure and differential pressure threshold; it determines the exhaust pressure setpoint based on the boiler load and deaerator pressure, and controls the exhaust pressure of the back pressure turbine to the exhaust pressure setpoint. In this situation, since the exhaust parameters of the back compressor do not meet the needs of heat users under the low-load conditions of deep regulation, an exhaust regulating valve and exhaust branch pipeline are added to lead the exhaust steam of the back compressor to the deaerator system under low-load conditions. The steam inlet and exhaust sides of the back compressor are regulated to ensure the unit operates under low load conditions during deep regulation. This improves the wide-load operation capability of the back compressor for industrial steam supply under deep regulation conditions. At this time, the back compressor does not stop operating when the exhaust parameters of the back compressor do not meet the needs of heat users, reducing the frequent start-up and shutdown operations of the back compressor.

[0037] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0038] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0039] Figure 1 This diagram illustrates a flow chart of a back-pressure turbine steam supply wide-load operation control method under deep-adjustment conditions, provided by an embodiment of the present invention.

[0040] Figure 2 This diagram illustrates a block diagram of the back-pressure turbine steam supply wide-load operation control system under deep-adjustment conditions provided in an embodiment of the present invention.

[0041] Figure 3 This is a block diagram of a back-pressure turbine steam supply wide-load operation control device under deep-adjustment conditions, used to implement the back-pressure turbine steam supply wide-load operation control method under deep-adjustment conditions in embodiments of the present invention. Detailed Implementation

[0042] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with those of the present invention. Rather, they are merely examples of apparatuses and methods consistent with some aspects of the embodiments of the present invention as detailed in the appended claims.

[0043] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0044] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified. It should also be understood that the term "and / or" as used in this invention refers to and includes any or all possible combinations of one or more associated listed items.

[0045] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0046] This invention provides a method and system for controlling the wide-load operation of back pressure turbine steam supply under deep-adjustment conditions. The main purpose is to improve the wide-load operation capability of back pressure turbine industrial steam supply under deep-adjustment conditions, so as to reduce the frequent start-up and shutdown of back pressure turbine.

[0047] In this invention, the back pressure compressor includes a high-temperature, low-pressure steam inlet branch, a high-pressure, low-temperature steam inlet branch, and a main steam inlet line. The high-temperature, low-pressure steam inlet branch and the high-pressure, low-temperature steam inlet branch are respectively connected to the steam inlet of the back pressure compressor via the main steam inlet line. The high-temperature, low-pressure steam inlet branch is used to transport high-temperature, low-pressure steam, the high-pressure, low-temperature steam inlet branch is used to transport high-pressure, low-temperature steam, and the main steam inlet line is used to transport a mixture of high-temperature, low-pressure steam and high-pressure, low-temperature steam. A first steam inlet regulating valve is installed on the high-temperature, low-pressure steam inlet branch, a second steam inlet regulating valve is installed on the high-pressure, low-temperature steam inlet branch, and a third steam inlet regulating valve is installed on the main steam inlet line.

[0048] The existing back-pressure turbine's exhaust outlet is connected to the user end via the main exhaust pipeline. This invention considers the general ideal selection principle for back-pressure turbines, which is for stable heat users with annual heating demand of 6000+ hours and only one exhaust parameter. Therefore, it primarily considers operation under load within the vicinity of this exhaust parameter. However, if participating in deep peak shaving (i.e., deep regulation), the back-pressure turbine's regulating valve adjustment margin is within a certain range as the inlet steam parameters change. Outside this adjustment range, such as at the lower limit of the adjustment range (i.e., low load conditions), the back-pressure turbine's exhaust parameters (mainly including temperature and pressure) are difficult to maintain to meet the heat user's needs. Therefore, this invention adds an exhaust regulating valve and an exhaust branch pipeline at the exhaust outlet. The inlet of the exhaust regulating valve is connected to the back-pressure turbine's exhaust outlet via the main exhaust pipeline, the first outlet of the exhaust regulating valve is connected to the user end via the main exhaust pipeline, and the second outlet of the exhaust regulating valve is connected to the deaerator system via the exhaust branch pipeline.

[0049] After adding an exhaust regulating valve and an exhaust branch pipeline, the control method of the present invention is specifically described from multiple aspects, including the back pressure unit body, the back pressure unit inlet side, and the back pressure unit exhaust side.

[0050] In the first embodiment, Figure 1 This diagram illustrates a flow chart of a back-pressure turbine steam supply wide-load operation control method under deep-adjustment conditions, provided by an embodiment of the present invention. Figure 1 As shown, the back-pressure turbine steam supply wide-load operation control method under deep adjustment conditions includes:

[0051] Step S11: When the back pressure unit is under low load, acquire the operating data of the back pressure unit, boiler load and deaerator pressure in real time.

[0052] In step S11, the factory design parameters are also obtained. The factory design parameters refer to the factory parameters of the back pressure machine body provided by the manufacturer. These factory parameters include parameters such as shaft system and thermal parameters.

[0053] In step S11, the acquired operating data includes, but is not limited to, the unit load of the back pressure unit, the steam supply temperature and pressure of the back pressure unit during actual operation.

[0054] In step S11, the acquired operating data also includes the back pressure turbine chamber pressure and the back pressure turbine exhaust pressure.

[0055] In step S11, the boiler load and deaerator pressure are obtained.

[0056] In step S11, the deaerator water level is also obtained.

[0057] Step S12: Calculate the minimum inlet steam flow and minimum active power of the back pressure unit based on the factory design parameters.

[0058] Step S12 also includes calculating the maximum steam inlet flow rate and maximum active power of the back pressure unit based on the factory design parameters; and performing a safety check based on the maximum steam inlet flow rate, minimum steam inlet flow rate, maximum active power, and minimum active power.

[0059] Specifically, in step S12, a system verification calculation (i.e., safety verification) is performed based on the factory design parameters. This system verification calculation includes, but is not limited to, calculating the maximum and minimum steam inlet flow rates of the back-compressor, the maximum and minimum active power of the back-compressor. Therefore, in this step, the maximum and minimum steam inlet flow rates, minimum and maximum active power of the back-compressor are calculated based on the factory design parameters, thus obtaining the boundary parameters for normal operation of the back-compressor. The minimum steam inlet flow rate and the corresponding minimum active power are the safe equivalent flow rate and the active power of the back-compressor generator when the back-compressor is operating at minimum output.

[0060] Step S13: Based on the factory design parameters and operating data, control the steam flow rate on the steam inlet side of the back pressure unit to the minimum steam flow rate, and control the back pressure unit to operate at the minimum active power value.

[0061] Specifically, step S13, controlling the steam flow rate on the back pressure turbine's inlet side to the minimum inlet flow rate based on factory design parameters and operating data, includes: acquiring steam parameter data for cold reheat, hot reheat, and first-stage extraction; adjusting the first and second inlet regulating valves based on factory design parameters, operating data, and steam parameter data to ensure the steam temperature and pressure in the main inlet circuit are at the set temperature and set pressure; and adjusting the third inlet regulating valve to ensure the steam flow rate at the back pressure turbine's inlet is the minimum inlet flow rate. The steam parameter data includes, but is not limited to, the steam temperature and pressure in the corresponding pipelines. By adjusting the first and second inlet regulating valves, the ratio of high-temperature low-pressure steam to high-pressure low-temperature steam in the mixed steam in the main inlet circuit can be adjusted. In this case, by optimizing the inlet side parameters at the deep-adjustment low-load lower limit operating point, the inlet steam quality is improved, ensuring the back pressure turbine operates above the minimum output condition while maintaining a certain margin.

[0062] Step S14: Control the exhaust regulating valve to connect the pipeline between the exhaust outlet of the back pressure unit and the deaerator system, and disconnect the pipeline between the exhaust outlet and the user end.

[0063] Considering that under low-load conditions, the exhaust parameters of the back compressor are difficult to maintain to meet the heat demand of industrial header users, the back compressor will stop operating. Furthermore, low-load conditions frequently occur in real-world applications. To reduce the frequent start-up and shutdown of the back compressor, step S14 controls the exhaust regulating valve to connect the pipeline between the back compressor's exhaust outlet and the deaerator system, while shutting off the pipeline between the exhaust outlet and the user end. At this time, the exhaust steam from the back compressor to the deaerator system can be supplied without stopping the back compressor.

[0064] Step S15: Calculate the differential pressure based on the operating data, and perform back pressure protection based on the differential pressure and differential pressure threshold.

[0065] Specifically, in step S15, the differential pressure is calculated based on the back pressure turbine chamber pressure and the exhaust pressure. That is, differential pressure = back pressure turbine chamber pressure - exhaust pressure.

[0066] In step S15, the differential pressure threshold includes a first differential pressure threshold and a second differential pressure threshold. The first differential pressure threshold is greater than the second differential pressure threshold. Back pressure protection is performed based on the differential pressure and the differential pressure threshold, including: if the differential pressure is greater than or equal to the first differential pressure threshold, a first preset time is delayed, and then the back pressure turbine trip protection is triggered; if the differential pressure is less than the first differential pressure threshold but greater than or equal to the second differential pressure threshold, an alarm is triggered, and simultaneously the first and second steam inlet regulating valves are closed at a set rate until the differential pressure drops to a preset proportion of the second differential pressure threshold. The alarm can be triggered via a high-intensity differential pressure indicator.

[0067] If the first differential pressure threshold is represented by HHH, the second differential pressure threshold is represented by HH, and HHH > HH, taking a first preset time of 3 seconds, a set rate of 0.1% / second, and a preset ratio of 80% as an example, in step S15, differential pressure high protection is set, and the back pressure machine differential pressure high level setting is implemented. The specific protection process is as follows:

[0068] a. If the differential pressure is high (HHH), then after a 3-second delay, the back pressure unit trip (ETS) protection will be triggered.

[0069] b. If the differential pressure is high (HH) but not high (HHH), an alarm will be triggered via the high differential pressure indicator, and the following actions will be activated simultaneously:

[0070] 1) The back pressure compressor switches to exhaust pressure control mode, power control mode, and valve position control mode.

[0071] 2) In valve position control mode, the first steam inlet regulating valve and the second steam inlet regulating valve are automatically closed at a rate of 0.1% / second until the differential pressure drops to 80% of the second differential pressure threshold HH, and then the closing stops.

[0072] In step S15, back-pressure turbine trip protection is also performed based on the deaerator water level and the deaerator water level threshold. If the deaerator water level threshold is 2550 mm, when the back-pressure turbine exhausts steam to the deaerator system, the deaerator water level is detected. If the deaerator water level is 2550 mm high, the back-pressure turbine trips after a 3-second delay.

[0073] In step S15, based on the deaerator water level and the deaerator water level threshold, a high water level trip back pressure protection is performed, including: if the deaerator water level is greater than or equal to the deaerator water level threshold, a second preset time is delayed, and then the back pressure trip protection is triggered.

[0074] In step S15, the back pressure protection settings are improved by combining differential pressure-based back pressure protection and high water level trip back pressure protection, thereby enhancing the safety and reliability of the back pressure unit.

[0075] Step S16: Determine the exhaust pressure setpoint based on boiler load and deaerator pressure, and control the exhaust pressure of the back pressure unit to the exhaust pressure setpoint.

[0076] Specifically, in step S16, if the back pressure protection in step S15 triggers the cut-off exhaust pressure control mode, the exhaust pressure control mode is not activated and the exhaust pressure is not controlled. The exhaust pressure setpoint can be made to track the actual exhaust pressure value. If the cut-off exhaust pressure control mode is not triggered and the exhaust pressure control mode is activated, the exhaust pressure setpoint is obtained through the added exhaust pressure setpoint automatic generation loop, and the exhaust pressure of the back pressure is controlled by the exhaust pressure setpoint.

[0077] In step S16, the newly added automatic exhaust pressure setpoint generation loop determines the exhaust pressure setpoint based on the boiler load and deaerator pressure. Specifically, the automatic exhaust pressure setpoint generation loop acquires historical data, including various boiler loads, various deaerator pressures, and various exhaust pressure change rates; based on different boiler loads and different deaerator pressures, it obtains the corresponding exhaust pressure setpoint function relationships under different exhaust pressure change rates; it inputs the set exhaust pressure change rate, selects the target exhaust pressure setpoint function relationship from the various exhaust pressure setpoint function relationships, and obtains the exhaust pressure setpoint based on the target exhaust pressure setpoint function relationship, the real-time acquired boiler load, and the deaerator pressure.

[0078] In step S16, the set exhaust pressure change rate is used to better control the changes in exhaust parameters.

[0079] In step S16, when the exhaust pressure control mode is engaged, adjustment can also be made by adding or subtracting offset (a basic operating method for power plant operators), which is divided into:

[0080] After entering the deep adjustment mode, that is, exhausting steam to the deaerator system, the exhaust pressure setpoint is automatically generated by the circuit based on the boiler load and the deaerator pressure to obtain the exhaust pressure setpoint.

[0081] After exiting the deep adjustment mode, i.e., venting steam to the user, the venting pressure setting value is restored to the default value.

[0082] In step S16, the safety and reliability of the back pressure unit are improved by optimizing the control method of the back pressure unit's exhaust pressure.

[0083] In one embodiment of the present invention, taking a megawatt-class ultra-supercritical steam turbine generator unit as an example, the power plant currently has an industrial steam supply heat load of [40,100] t / h, and exhaust parameters of 1.3 MPa and 320℃. The long-term load is expected to reach 240 t / h.

[0084] According to the latest deep peak shaving requirements of the local power grid, the minimum continuous stable operating load should reach a single unit power deep adjustment to 35%Pe. That is, when the main unit operates in the [35%, 50%]Pe load range, the low-temperature reheat steam pressure and temperature are low (according to the heat balance diagram, the pressure is [2.809, 3.691] MPa.a, and the temperature is [358.5, 360.5]℃). After the low-temperature reheat steam does work through the back pressure turbine, the exhaust parameters of the back pressure turbine cannot meet the industrial steam supply pressure and temperature requirements of 1.3 MPa and 320℃. Moreover, according to the latest dispatching and peak shaving requirements, the low-load operating time is relatively long every day. If the back pressure turbine exhaust cannot meet the industrial heating demand, the back pressure turbine will be shut down. The frequent start-up and shutdown of the back pressure turbine every day due to load changes is not conducive to the safe and reliable operation of the back pressure turbine. In addition, each start-up of the back pressure turbine results in a large amount of start-up exhaust, with significant loss of working fluid and heat. The back pressure turbine heating system originally designed for basic load cannot meet the new deep peak shaving requirements.

[0085] The control method for wide-load operation of the back pressure unit under deep-adjustment conditions is as follows:

[0086] 1) Data acquisition steps: When the back pressure unit is under low load, acquire the back pressure unit's operating data, boiler load, and deaerator pressure in real time.

[0087] 2) Back-compression turbine safety verification steps: Based on the design parameters, calculate the maximum and minimum inlet steam flow rates of the back-compression turbine, and the corresponding active power of the back-compression generator (i.e., maximum and minimum active power). Based on the calculations, it can be seen that under the 35% THA boundary condition, with inlet steam parameters of 2.437 MPa / 357.9℃ and exhaust steam parameters of 0.38 MPa, the back-compression turbine can operate safely. Here, THA refers to the heat rate acceptance condition, which is the power output of the turbine under rated inlet steam parameters, rated back pressure, normal operation of the regenerative system, 0% makeup water rate, and continuous operation.

[0088] 3) Back-compression turbine inlet steam side optimization steps: Obtain steam parameter data for cold reheat, hot reheat, and first-stage extraction; based on factory design parameters, operating data, and steam parameter data, adjust the first and second inlet steam regulating valves to ensure the steam temperature and pressure in the main inlet steam path are at the set temperature and set pressure; adjust the third inlet steam regulating valve to ensure the steam flow rate at the back-compression turbine inlet is at the minimum inlet steam flow rate. Thus, by adjusting the inlet steam parameter ratio in conjunction with cold reheat, hot reheat, and first-stage extraction at the unit's deep adjustment low-load lower limit operating point, the quality of the inlet steam parameters is improved.

[0089] 4) Optimization steps for the exhaust side of the back-pressure turbine: The back-pressure turbine generator set (hereinafter referred to as the back-pressure turbine) is set to operate in a heat-driven power generation mode, and the generated electricity is connected to the plant power system via industrial frequency. The normal operating steam source is a mixture of boiler first-stage reheater outlet steam (i.e., low-pressure, high-temperature steam) and reheater cold-section steam (i.e., high-pressure, low-temperature steam). Calculations show that when the unit operates within the [35%, 50%]Pe range, the mixed steam, after being processed by the back-pressure turbine, results in exhaust parameters {pressure [0.49, 0.66] MPa, temperature [185.1, 227.3] ℃} that do not meet the industrial steam requirements (pressure 1.3 MPa, temperature 320 ℃). Under this condition, the back-pressure turbine must be shut down. Therefore, an exhaust regulating valve and an exhaust branch pipeline are added to control the exhaust regulating valve to exhaust steam from the back compressor to the deaerator system. Thus, under low load conditions, if the exhaust parameters of the back compressor do not meet the needs of industrial users, the back compressor can be switched to the bypass deaerator system without stopping the operation of the back compressor.

[0090] 5) Back pressure protection setting optimization steps: including differential pressure-based back pressure protection and high water level trip back pressure protection.

[0091] Specifically, for the back pressure protection based on differential pressure: the original low exhaust pressure protection is cancelled, a high differential pressure protection is set, and a new high differential pressure indicator alarm is added. The high differential pressure level setting for the back pressure unit is as follows: calculate the differential pressure; if the differential pressure is high (HHH), after a 3-second delay, trigger the back pressure unit ETS protection; if the differential pressure is high (HH), the alarm will trigger the following actions simultaneously: first, the back pressure unit will disconnect the exhaust pressure control mode, disconnect the power control mode, and switch to valve position control mode; then, the back pressure unit will automatically close the first and second inlet steam regulating valves at a rate of 0.1% / second until the differential pressure drops to 80% of the differential pressure alarm value (HH).

[0092] For high water level trip back pressure generator protection: Add a high water level trip back pressure generator protection setting for deaerator. That is, when the back pressure generator exhausts steam to the deaerator, if the deaerator water level is higher than the protection water level HHH (2550MM), the back pressure generator will trip after a delay of 3 seconds.

[0093] 6) Optimization steps for back-pressure turbine exhaust pressure control mode: When the exhaust pressure control mode is not activated, the exhaust pressure setpoint tracks the actual exhaust pressure value; when the exhaust pressure control mode is activated, the exhaust pressure setpoint is automatically generated using the exhaust pressure setpoint, the exhaust pressure change rate is input, the exhaust pressure setpoint is obtained, and the exhaust pressure of the back-pressure turbine is controlled to be the exhaust pressure setpoint. Specifically, under the exhaust pressure control mode, adjustment can be made by adding or subtracting offsets, specifically: after entering the deep adjustment mode, the exhaust pressure setpoint is generated by correction based on boiler load and deaerator pressure; after exiting the deep adjustment mode, the back-pressure turbine exhaust pressure setpoint returns to its default value.

[0094] The above steps have enabled the back compressor to operate under wide load conditions with steam supply under deep adjustment conditions. The operating parameters of the back compressor under low load conditions are shown in Table 1.

[0095] Table 1. Operating parameters of the back pressure compressor under low load conditions.

[0096]

[0097] In the back-pressure turbine steam supply wide-load operation control method under deep-adjustment conditions of this invention embodiment, the exhaust outlet of the back-pressure turbine is connected to the user end via an exhaust main pipeline. An exhaust regulating valve and an exhaust branch pipeline are added at the exhaust outlet. The inlet of the exhaust regulating valve is connected to the exhaust outlet of the back-pressure turbine via the exhaust main pipeline. The first outlet of the exhaust regulating valve is connected to the user end via the exhaust main pipeline. The second outlet of the exhaust regulating valve is connected to the deaerator system via the exhaust branch pipeline. The control method includes: when the back-pressure turbine is under low-load conditions, acquiring in real time the factory design parameters and operating data of the back-pressure turbine, as well as the boiler load and deaerator pressure. The system calculates the minimum steam inlet flow rate and minimum active power of the back pressure turbine based on the factory design parameters; controls the steam flow rate on the steam inlet side of the back pressure turbine to the minimum steam inlet flow rate based on the factory design parameters and operating data, and controls the back pressure turbine to operate according to the minimum active power; controls the exhaust regulating valve to connect the pipeline between the exhaust outlet of the back pressure turbine and the deaerator system, and shuts off the pipeline between the exhaust outlet and the user end; calculates the differential pressure based on the operating data, and performs back pressure turbine protection based on the differential pressure and differential pressure threshold; determines the exhaust pressure setpoint based on the boiler load and deaerator pressure, and controls the exhaust pressure of the back pressure turbine to the exhaust pressure setpoint. In this situation, since the exhaust parameters of the back compressor do not meet the needs of heat users under the low-load conditions of deep regulation, an exhaust regulating valve and exhaust branch pipeline are added to lead the exhaust steam of the back compressor to the deaerator system under low-load conditions. The steam inlet and exhaust sides of the back compressor are regulated to ensure the unit operates under low load conditions during deep regulation. This improves the wide-load operation capability of the back compressor for industrial steam supply under deep regulation conditions. At this time, the back compressor does not stop operating when the exhaust parameters of the back compressor do not meet the needs of heat users, reducing the frequent start-up and shutdown operations of the back compressor.

[0098] The control method disclosed herein firstly derives the normal operating boundary parameters of the back-compressor through on-system verification calculations, including the safe equivalent flow rate at minimum output and the corresponding active power of the back-compressor generator. Secondly, by optimizing the re-intake steam source parameters at the deep-load low-limit operating point, the quality of the incoming steam is improved, ensuring that the back-compressor operates above the minimum output condition while maintaining a certain margin. Thirdly, the exhaust steam from the back-compressor is led to the deaerator system, ensuring that when the exhaust steam parameters of the back-compressor do not meet the heat user's needs during deep-load low-load operation, the back-compressor can be switched to the bypass deaerator system without interrupting operation, reducing frequent start-stop operations of the back-compressor. Finally, the back-compressor is controlled and protected through optimized protection settings and control modes, thereby improving the safety and reliability of the back-compressor unit, reducing working fluid waste and heat loss, reducing the harm to the life of the back-compressor, and reducing the safety risks to the unit operation. It is suitable for deep peak-shaving conditions, enhances the wide-load operation capability of industrial steam supply back-compressors, and has been successfully applied in project practice.

[0099] The following are system embodiments of the present invention, which can be used to execute the method embodiments of the present invention. For details not disclosed in the system embodiments of the present invention, please refer to the method embodiments of the present invention.

[0100] Please see Figure 2 , Figure 2 This diagram illustrates a block diagram of a back-pressure turbine steam supply wide-load operation control system under deep-adjustment conditions, provided in an embodiment of the present invention. This back-pressure turbine steam supply wide-load operation control system can be implemented as a whole or part of a system through software, hardware, or a combination of both. In this embodiment, the exhaust outlet of the back-pressure turbine is connected to the user end via a main exhaust pipeline. An exhaust regulating valve and an exhaust branch pipeline are added at the exhaust outlet. The inlet of the exhaust regulating valve is connected to the exhaust outlet of the back-pressure turbine via the main exhaust pipeline. The first outlet of the exhaust regulating valve is connected to the user end via the main exhaust pipeline, and the second outlet of the exhaust regulating valve is connected to the deaerator system via the exhaust branch pipeline. The back-pressure turbine steam supply wide-load operation control system 10 under deep-adjustment conditions includes an acquisition module 11, a verification calculation module 12, a steam inlet control module 13, an exhaust module 14, a heating control module 15, a protection setting module 16, and an exhaust control module 17, wherein:

[0101] The acquisition module 11 is used to acquire the operating data of the back pressure machine, boiler load and deaerator pressure in real time when the back pressure machine is under low load conditions.

[0102] Verification calculation module 12 is used to calculate the minimum inlet steam flow and minimum active power of the back pressure unit based on the factory design parameters;

[0103] The steam inlet control module 13 is used to control the steam flow rate on the steam inlet side of the back pressure unit to the minimum steam inlet flow rate based on the factory design parameters and operating data, and to control the back pressure unit to operate at the minimum active power value.

[0104] The exhaust module 14 includes an exhaust regulating valve, an exhaust branch pipeline, and a deaerator system. The inlet of the exhaust regulating valve is connected to the exhaust outlet of the back pressure unit via the exhaust main pipeline. The first outlet of the exhaust regulating valve is connected to the user end via the exhaust main pipeline. The second outlet of the exhaust regulating valve is connected to the deaerator system via the exhaust branch pipeline.

[0105] The heating control module 15 is used to control the exhaust regulating valve so that the pipeline between the exhaust outlet of the back pressure unit and the deaerator system is connected, and the pipeline between the exhaust outlet and the user end is closed.

[0106] Protection setting module 16 is used to calculate differential pressure based on operating data and to perform back pressure protection based on differential pressure and differential pressure threshold.

[0107] The exhaust control module 17 is used to determine the exhaust pressure setpoint based on the boiler load and deaerator pressure, and control the exhaust pressure of the back pressure machine to the exhaust pressure setpoint.

[0108] Optionally, the verification calculation module 12 is also used to calculate the maximum steam inlet flow and maximum active power of the back pressure unit based on the factory design parameters; and to perform safety verification based on the maximum steam inlet flow, minimum steam inlet flow, maximum active power, and minimum active power.

[0109] Optionally, the back pressure unit includes a high-temperature low-pressure steam inlet branch, a high-pressure low-temperature steam inlet branch, and a main steam inlet branch. The high-temperature low-pressure steam inlet branch and the high-pressure low-temperature steam inlet branch are respectively connected to the steam inlet of the back pressure unit via the main steam inlet branch. A first steam inlet regulating valve is installed on the high-temperature low-pressure steam inlet branch, a second steam inlet regulating valve is installed on the high-pressure low-temperature steam inlet branch, and a third steam inlet regulating valve is installed on the main steam inlet branch. The steam inlet control module 13 is specifically used for: acquiring steam parameter data of cold reheat, hot reheat, and first-stage extraction; adjusting the first and second steam inlet regulating valves based on factory design parameters, operating data, and steam parameter data to make the steam temperature in the main steam inlet branch the set temperature and the steam pressure the set pressure; and adjusting the third steam inlet regulating valve to make the steam flow rate at the inlet of the back pressure unit the minimum steam flow rate.

[0110] Optionally, the operating data includes the back compressor wheel chamber pressure and the back compressor exhaust pressure. The protection setting module 16 is specifically used to calculate the differential pressure based on the back compressor wheel chamber pressure and the exhaust pressure.

[0111] Optionally, the differential pressure threshold includes a first differential pressure threshold and a second differential pressure threshold, wherein the first differential pressure threshold is greater than the second differential pressure threshold. The protection setting module 16 is specifically used for: if the differential pressure is greater than or equal to the first differential pressure threshold, then delaying for a first preset time, and then triggering the back pressure unit trip protection; if the differential pressure is less than the first differential pressure threshold but greater than or equal to the second differential pressure threshold, then issuing an alarm reminder, and simultaneously closing the first steam inlet regulating valve and the second steam inlet regulating valve at a set rate until the differential pressure drops to the second differential pressure threshold at a preset ratio.

[0112] Optionally, the acquisition module 11 is also used to acquire the deaerator water level, and the protection setting module 16 is also used to: perform high water level trip back pressure protection based on the deaerator water level and the deaerator water level threshold.

[0113] Optionally, the protection setting module 16 is specifically used to: if the deaerator water level is greater than or equal to the deaerator water level threshold, delay for a second preset time, and then trigger the back pressure unit trip protection.

[0114] Optionally, the exhaust control module 17 is specifically used for: acquiring historical data, including various boiler loads, various deaerator pressures, and various exhaust pressure change rates; obtaining the corresponding exhaust pressure setpoint function relationship under different exhaust pressure change rates based on different boiler loads and different deaerator pressures; inputting the set exhaust pressure change rate; selecting the target exhaust pressure setpoint function relationship from the various exhaust pressure setpoint function relationships; and obtaining the exhaust pressure setpoint value based on the target exhaust pressure setpoint function relationship, the real-time acquired boiler load, and the deaerator pressure.

[0115] It should be noted that the back-pressure turbine steam supply wide-load operation control system under deep-adjustment conditions provided in the above embodiments is only illustrated by the division of the above functional modules when executing the back-pressure turbine steam supply wide-load operation control method under deep-adjustment conditions. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the back-pressure turbine steam supply wide-load operation control equipment under deep-adjustment conditions can be divided into different functional modules to complete all or part of the functions described above. In addition, the back-pressure turbine steam supply wide-load operation control system under deep-adjustment conditions provided in the above embodiments and the back-pressure turbine steam supply wide-load operation control method embodiments under deep-adjustment conditions belong to the same concept, and the implementation process is detailed in the method embodiments, which will not be repeated here.

[0116] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0117] In the back-pressure turbine steam supply wide-load operation control system under deep-adjustment conditions of this invention, the acquisition module is used to acquire the back-pressure turbine's operating data, boiler load, and deaerator pressure in real time when the back-pressure turbine is under low-load conditions; the verification calculation module is used to calculate the minimum steam inlet flow rate and minimum active power of the back-pressure turbine based on the factory design parameters; the steam inlet control module is used to control the steam flow rate on the back-pressure turbine's inlet side to the minimum steam inlet flow rate based on the factory design parameters and operating data, and control the back-pressure turbine to operate according to the minimum active power; the exhaust module includes an exhaust regulating valve, exhaust branch pipelines, and a deaerator system, with the inlet of the exhaust regulating valve connected to the exhaust... The main pipeline connects to the exhaust outlet of the back pressure unit. The first outlet of the exhaust regulating valve is connected to the user end via the main exhaust pipeline, and the second outlet of the exhaust regulating valve is connected to the deaerator system via the exhaust branch pipeline. The heating control module controls the exhaust regulating valve to connect the pipeline between the exhaust outlet of the back pressure unit and the deaerator system, and to disconnect the pipeline between the exhaust outlet and the user end. The protection setting module calculates the differential pressure based on the operating data and performs back pressure unit protection based on the differential pressure and differential pressure threshold. The exhaust control module determines the exhaust pressure setpoint based on the boiler load and deaerator pressure, and controls the exhaust pressure of the back pressure unit to be the exhaust pressure setpoint. In this situation, since the exhaust parameters of the back compressor do not meet the needs of heat users under the low-load conditions of deep regulation, an exhaust regulating valve and exhaust branch pipeline are added to lead the exhaust steam of the back compressor to the deaerator system under low-load conditions. The steam inlet and exhaust sides of the back compressor are regulated to ensure the unit operates under low load conditions during deep regulation. This improves the wide-load operation capability of the back compressor for industrial steam supply under deep regulation conditions. At this time, the back compressor does not stop operating when the exhaust parameters of the back compressor do not meet the needs of heat users, reducing the frequent start-up and shutdown operations of the back compressor.

[0118] According to embodiments of the present invention, the present invention also provides a back-pressure turbine steam supply wide-load operation control device under deep-adjustment conditions, a readable storage medium, and a computer program product.

[0119] Figure 3 This is a block diagram of a back-pressure turbine steam supply wide-load operation control device under deep-tuning operating conditions, used to implement the back-pressure turbine steam supply wide-load operation control method under deep-tuning operating conditions according to embodiments of the present invention. The back-pressure turbine steam supply wide-load operation control device under deep-tuning operating conditions is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workbenches, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The back-pressure turbine steam supply wide-load operation control device under deep-tuning operating conditions can also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable electronic devices, and other similar computing devices. The components, connections and relationships of components, and functions shown in this invention are merely examples and are not intended to limit the implementation of the invention described and / or claimed herein.

[0120] like Figure 3 As shown, the back-pressure turbine steam supply wide-load operation control device 20 under deep-adjustment conditions includes a computing unit 21, which can perform various appropriate actions and processes based on a computer program stored in a read-only memory (ROM) 22 or a computer program loaded from a storage unit 28 into a random access memory (RAM) 23. The RAM 23 can also store various programs and data required for the operation of the back-pressure turbine steam supply wide-load operation control device 20 under deep-adjustment conditions. The computing unit 21, ROM 22, and RAM 23 are interconnected via a bus 24. An input / output (I / O) interface 25 is also connected to the bus 24.

[0121] Multiple components in the back-pressure turbine steam supply wide-load operation control device 20 under deep-condition operating conditions are connected to the I / O interface 25, including: an input unit 26, such as a keyboard, mouse, etc.; an output unit 27, such as various types of displays, speakers, etc.; a storage unit 28, such as a disk, optical disk, etc., which is communicatively connected to the computing unit 21; and a communication unit 29, such as a network card, modem, wireless transceiver, etc. The communication unit 29 allows the back-pressure turbine steam supply wide-load operation control device 20 under deep-condition operating conditions to exchange information / data with other back-pressure turbine steam supply wide-load operation control devices under deep-condition operating conditions through computer networks such as the Internet and / or various telecommunications networks.

[0122] The computing unit 21 can be various general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of the computing unit 21 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various computing units running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. The computing unit 21 executes the various methods and processes described above, such as executing the back-pressure turbine steam supply wide-load operation control method under deep-tuning conditions. For example, in some embodiments, the back-pressure turbine steam supply wide-load operation control method under deep-tuning conditions can be implemented as a computer software program, which is tangibly contained in a machine-readable medium, such as storage unit 28. In some embodiments, part or all of the computer program can be loaded and / or installed on the back-pressure turbine steam supply wide-load operation control device 20 under deep-tuning conditions via ROM 22 and / or communication unit 29. When the computer program is loaded into RAM 23 and executed by the computing unit 21, one or more steps of the back-pressure turbine steam supply wide-load operation control method under deep-tuning conditions described above can be performed. Alternatively, in other embodiments, the computing unit 21 may be configured by any other suitable means (e.g., by means of firmware) to perform a back-compressor steam supply wide-load operation control method under deep-tuning conditions.

[0123] Various embodiments of the systems and techniques described above in this invention can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), payload-programmable logic electronic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0124] The program code used to implement the methods of the present invention can be written in any combination of one or more programming languages. This program code can be provided to a processor or controller of a general-purpose computer, special-purpose computer, or other programmable data processing device, such that when executed by the processor or controller, the program code causes the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code can be executed entirely on the machine, partially on the machine, as a standalone software package partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0125] In this invention, a machine-readable medium can be a tangible medium that may contain or store a program for use by an instruction execution system, apparatus, or back-pressure turbine steam supply wide-load operation control device under deep-condition conditions, or for use in conjunction with such an instruction execution system, apparatus, or back-pressure turbine steam supply wide-load operation control device. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. Machine-readable media can be, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatuses, or electronic devices, or any suitable combination of the foregoing. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage electronics, magnetic storage electronics, or any suitable combination of the foregoing.

[0126] To provide interaction with a user, the systems and techniques described herein can be implemented on a computer having: a display device for displaying information to the user (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor); and a keyboard and pointing device (e.g., a mouse or trackball) through which the user provides input to the computer. Other types of devices can also be used to provide interaction with the user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).

[0127] The systems and technologies described herein can be implemented in computing systems that include backend components (e.g., as data servers), or middleware components (e.g., application servers), or frontend components (e.g., user computers with graphical user interfaces or web browsers through which users can interact with implementations of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium (e.g., communication networks). Examples of communication networks include local area networks (LANs), wide area networks (WANs), the Internet, and blockchain networks.

[0128] Computer systems can include clients and servers. Clients and servers are generally geographically separated and typically interact via communication networks. The client-server relationship is created by computer programs running on the respective computers and having a client-server relationship with each other. A server can be a cloud server, also known as a cloud computing server or cloud host, a hosting product within the cloud computing service system that addresses the shortcomings of traditional physical hosts and VPS (Virtual Private Server) services, such as high management difficulty and weak business scalability. Servers can also be servers for distributed systems or servers incorporating blockchain technology.

[0129] It should be understood that the various forms of processes shown above can be used to reorder, add, or delete steps. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this invention can be achieved, and this invention does not impose any limitations on them.

[0130] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method for controlling the operation of a back-pressure turbine under deep-adjustment conditions with wide-load steam supply, characterized in that, The exhaust outlet of the back pressure unit is connected to the user end via a main exhaust pipeline. An exhaust regulating valve and an exhaust branch pipeline are added to the exhaust outlet. The inlet of the exhaust regulating valve is connected to the exhaust outlet of the back pressure unit via the main exhaust pipeline. The first outlet of the exhaust regulating valve is connected to the user end via the main exhaust pipeline. The second outlet of the exhaust regulating valve is connected to the deaerator system via the exhaust branch pipeline. The control method includes: When the back pressure unit is under low load, the operating data of the back pressure unit, boiler load and deaerator pressure are acquired in real time. Calculate the minimum steam inlet flow and minimum active power of the back pressure unit based on the factory design parameters; Based on the factory design parameters and the operating data, the steam flow rate on the steam inlet side of the back pressure unit is controlled to be the minimum steam inlet flow rate, and the back pressure unit is controlled to operate according to the minimum active power value. Control the exhaust regulating valve to connect the exhaust outlet of the back pressure unit to the deaerator system, and disconnect the exhaust outlet from the user terminal. The differential pressure is calculated based on the operating data, and back pressure protection is performed based on the differential pressure and differential pressure threshold. The operating data includes the back pressure turbine wheel chamber pressure and the back pressure turbine exhaust pressure. The differential pressure is calculated based on the back pressure turbine wheel chamber pressure and the exhaust pressure. The exhaust pressure setpoint is determined based on the boiler load and the deaerator pressure, and the exhaust pressure of the back pressure compressor is controlled to be the exhaust pressure setpoint.

2. The back-pressure turbine steam supply wide-load operation control method under deep-adjustment conditions as described in claim 1, characterized in that, The back pressure unit includes a high-temperature and low-pressure steam inlet branch, a high-pressure and low-temperature steam inlet branch, and a main steam inlet. The high-temperature and low-pressure steam inlet branch and the high-pressure and low-temperature steam inlet branch are respectively connected to the steam inlet of the back pressure unit via the main steam inlet. A first steam inlet regulating valve is provided on the high-temperature and low-pressure steam inlet branch, a second steam inlet regulating valve is provided on the high-pressure and low-temperature steam inlet branch, and a third steam inlet regulating valve is provided on the main steam inlet. The control of the steam flow rate on the inlet side of the back pressure unit to the minimum inlet steam flow rate based on the factory design parameters and the operating data includes: Obtain steam parameter data for cold reheat, hot reheat, and first-stage extraction; Based on the factory design parameters, the operating data, and the steam parameter data, adjust the first steam inlet regulating valve and the second steam inlet regulating valve to make the steam temperature in the steam inlet circuit the set temperature and the steam pressure the set pressure; adjust the third steam inlet regulating valve to make the steam flow rate at the inlet of the back pressure unit the minimum steam flow rate.

3. The back-pressure turbine steam supply wide-load operation control method under deep-adjustment conditions as described in claim 1, characterized in that, The differential pressure threshold includes a first differential pressure threshold and a second differential pressure threshold, wherein the first differential pressure threshold is greater than the second differential pressure threshold, and the back pressure protection based on the differential pressure and the differential pressure threshold includes: If the differential pressure is greater than or equal to the first differential pressure threshold, then delay for a first preset time, and then trigger the back pressure unit trip protection. If the differential pressure is less than the first differential pressure threshold but greater than or equal to the second differential pressure threshold, an alarm is triggered, and the first and second steam inlet regulating valves are closed at a set rate until the differential pressure drops to a preset proportion of the second differential pressure threshold.

4. The back-pressure turbine steam supply wide-load operation control method under deep-adjustment conditions as described in claim 3, characterized in that, It also includes obtaining the deaerator water level and performing high-level trip back pressure protection based on the deaerator water level and the deaerator water level threshold.

5. The back-pressure turbine steam supply wide-load operation control method under deep-adjustment conditions as described in claim 4, characterized in that, The high-level trip back pressure protection based on the deaerator water level and the deaerator water level threshold includes: If the deaerator water level is greater than or equal to the deaerator water level threshold, then a second preset time is delayed, and then the back pressure unit trip protection is triggered.

6. The back-pressure turbine steam supply wide-load operation control method under deep-adjustment conditions as described in claim 5, characterized in that, The process of determining the exhaust pressure setpoint based on the boiler load and the deaerator pressure includes: Acquire historical data, including various boiler loads, various deaerator pressures, and various exhaust steam pressure change rates; Based on different boiler loads and different deaerator pressures, the corresponding exhaust pressure setting function relationship under different exhaust pressure change rates is obtained; Input the set exhaust pressure change rate, select the target exhaust pressure setting function relationship from the various exhaust pressure setting function relationships, and obtain the exhaust pressure setting value based on the target exhaust pressure setting function relationship, the real-time boiler load and deaerator pressure.

7. The back-pressure turbine steam supply wide-load operation control method under deep-adjustment conditions as described in claim 1, characterized in that, Also includes: The maximum steam inlet flow and maximum active power of the back pressure unit are calculated based on the aforementioned factory design parameters. Safety verification is performed based on the maximum and minimum steam inlet flow rates, maximum and minimum active power values.

8. A back-pressure turbine steam supply wide-load operation control system under deep-adjustment conditions, characterized in that, include: The acquisition module is used to acquire real-time operating data of the back pressure unit, boiler load, and deaerator pressure when the back pressure unit is under low load conditions. The verification calculation module is used to calculate the minimum inlet steam flow and minimum active power of the back pressure unit based on the factory design parameters. The steam inlet control module is used to control the steam flow rate on the steam inlet side of the back pressure unit to the minimum steam inlet flow rate based on the factory design parameters and the operating data, and to control the back pressure unit to operate according to the minimum active power value. The exhaust module includes an exhaust regulating valve, an exhaust branch pipeline, and a deaerator system. The inlet of the exhaust regulating valve is connected to the exhaust outlet of the back pressure unit via the exhaust main pipeline. The first outlet of the exhaust regulating valve is connected to the user end via the exhaust main pipeline. The second outlet of the exhaust regulating valve is connected to the deaerator system via the exhaust branch pipeline. The heating control module is used to control the exhaust regulating valve so that the pipeline between the exhaust outlet of the back pressure unit and the deaerator system is connected, and the pipeline between the exhaust outlet and the user terminal is closed. A protection setting module is used to calculate differential pressure based on the operating data, and to perform back pressure protection based on the differential pressure and differential pressure threshold. The operating data includes the back pressure wheel chamber pressure and the back pressure exhaust pressure. The differential pressure is calculated based on the back pressure wheel chamber pressure and the exhaust pressure. The exhaust control module is used to determine the exhaust pressure setpoint based on the boiler load and the deaerator pressure, and control the exhaust pressure of the back pressure unit to be the exhaust pressure setpoint.

9. A back-pressure turbine steam supply wide-load operation control device under deep-adjustment conditions, characterized in that, include: At least one processor; The at least one processor is also connected in communication with a memory; wherein the memory stores instructions that can be executed by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform the back pressure turbine steam supply wide load operation control method under deep adjustment conditions as described in any one of claims 1-7.

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