Backpressure turbine steam supply operation control method and system adaptive to wide-load working condition and electronic equipment

Abstract

The invention relates to the technical field of backpressure turbines, in particular to a backpressure turbine steam supply operation control method and system adaptive to a wide-load working condition and electronic equipment. The control method comprises the following steps: S1, obtaining Q input, Qmin, P input and P row; s2, if the voltage difference between the P input and the P row is lt; s5, setting the backpressure set value as P <->-P <->, and performing S5; otherwise, performing S3; s3, if Q is larger than or equal to Qmin, the back pressure set value is set as rated back pressure, and S5 is carried out; otherwise, performing S4; s4, the backpressure set value is adjusted according to the final-stage minimum cooling flow curve under the variable backpressure working condition, it is guaranteed that Q < in > is larger than the minimum cooling flow allowable value, and S5 is carried out; and S5, the back pressure machine is controlled to operate according to the set back pressure set value. The dynamic adaptive working condition change of the back pressure turbine can be realized, the steam is continuously and stably supplied, and the operation flexibility, safety and economical efficiency of the back pressure turbine are improved.

Description

Technical Field

[0001] This invention relates to the field of back pressure compressor technology, and more specifically to a back pressure compressor steam supply operation control method, system and electronic equipment adapted to a wide range of load conditions. Background Technology

[0002] To meet the peak-shaving demands of the power grid, the current power system places higher requirements on the operational flexibility of thermal power plants. Simultaneously, thermal power plants are gradually integrating steam and heat supply with power generation to improve energy efficiency. The back-compression turbine operation mode, which combines steam extraction and supply, has become a commonly used steam supply solution for thermal power plants due to its ability to achieve cascaded utilization of steam energy. Its core operating mode involves extracting steam from the reheat steam section. After entering the back-compression turbine, the steam first converts some of its thermal energy into mechanical energy, typically used to drive the generator. The exhaust steam then enters the heating system and is distributed to various industrial heat users via pipelines to meet their steam needs during production. This mode, to a certain extent, achieves synergy between power generation and steam supply, becoming an important technical path connecting thermal power generation systems with industrial steam supply needs.

[0003] However, in practical applications, this operating mode is limited by fluctuations in operating conditions and system characteristics, resulting in several technical defects and making it difficult to fully adapt to the dual demands of thermal power peak shaving and industrial steam supply. First, the back-pressure turbine has poor adaptability to load changes and cannot meet the frequent peak shaving requirements of the power grid. When the thermal power unit is operating at low load, the extraction pressure of the reheat steam hot section will drop significantly as the unit load decreases, leading to insufficient back-pressure turbine inlet pressure. This makes it impossible to maintain its designed rated back pressure, resulting in a significant reduction in the back-pressure turbine's working efficiency, and even unstable working conditions. To ensure stable steam supply pressure, it is necessary to adjust the unit load or suspend back-pressure turbine operation, conflicting with the power grid's peak shaving requirements. Second, the steam flow rate at the user end fluctuates frequently, while the back-pressure turbine, in rated back pressure operation mode, has a minimum requirement for inlet steam flow, i.e., a minimum cooling flow rate, which must meet the requirements for cooling the last stage blades and stable operation of the back-pressure turbine. When the user's steam flow decreases, causing the steam inlet flow to the back pressure compressor to fall below the minimum cooling flow, the exhaust temperature rises rapidly. This keeps the last-stage blades of the back pressure compressor in an overheated environment for extended periods. This not only accelerates blade material aging but may also lead to blade deformation, cracks, and other safety hazards, seriously threatening the operational safety of the back pressure compressor. Furthermore, to address the aforementioned load and flow fluctuations, the current operating method requires frequent start-up and shutdown operations on the back pressure compressor. Frequent start-up and shutdown not only reduce overall energy efficiency but also shorten equipment lifespan and increase the risk of start-up failures and component damage, which is detrimental to the long-term stable operation of the back pressure compressor.

[0004] CN 117027975 A provides a method and system for controlling the operation of a back-pressure turbine under deep-load conditions with wide-load steam supply. The technical approach involves adding an exhaust regulating valve and an exhaust branch pipeline to the exhaust outlet of the back-pressure turbine. 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 main steam supply pipeline at the user end, and the second outlet is connected to the deaerator system via the exhaust branch pipeline. When the back-pressure turbine is under low-load conditions, real-time operating data of the back-pressure turbine, boiler load, and deaerator pressure are acquired. Based on the factory design parameters of the back-pressure turbine, the minimum inlet steam flow rate and minimum active power are calculated. The inlet steam flow rate is controlled at the minimum inlet steam flow rate by adjusting the inlet-side regulating valve, while simultaneously controlling the back-pressure turbine to operate at the minimum active power. The exhaust path is then switched via the exhaust regulating valve, allowing the exhaust steam to switch from the user end to the bypass deaerator system, avoiding shutdowns when exhaust parameters do not meet user requirements and reducing frequent start-up and shutdown operations of the back-pressure turbine. This technical solution can alleviate the problem of back-pressure turbine shutdown under low load to some extent, but its essence is to transfer exhaust steam from the steam supply circuit to the deaerator circuit, failing to achieve continuous steam supply to industrial users under low load conditions. When the power grid is in a low-load peak-shaving period and industrial users still have steam supply needs, this solution cannot take into account both peak shaving and steam supply, resulting in industrial steam supply interruption, which is incompatible with the dual functional requirements of power plants for peak shaving and industrial steam supply. Summary of the Invention

[0005] To address the technical problem that existing back-compression turbine operation methods cannot meet the needs of load peak shaving, this invention provides a back-compression turbine steam supply operation control method, system, and electronic equipment adaptable to a wide range of load conditions. This invention enables the back-compression turbine to dynamically adapt to changes in operating conditions and maintain a continuous and stable steam supply, thereby improving the flexibility, safety, and economy of back-compression turbine operation.

[0006] The technical solution of this invention is as follows: In a first aspect, the present invention provides a back-compression compressor steam supply operation control method adapted to wide load conditions, comprising the following steps: S1. Obtain the inlet steam flow rate Q of the back pressure unit. 入 Rated back pressure allows minimum flow rate Q min Inlet pressure P 入 and exhaust pressure P 排 ; S2, according to P 入 With P 排 Calculate the pressure difference; if the pressure difference is less than the safe pressure difference P... 安 Set the back pressure setting to P. 入 -P 安 Then proceed to step S5; Otherwise, proceed to step S3; S3, Comparison Q 入 and Q min The size relationship, if Q入 ≥Q min Set the back pressure setting value to the rated back pressure of the back pressure machine, and then proceed to step S5; Otherwise, proceed to step S4; S4. Adjust the back pressure setpoint according to the minimum cooling flow rate curve of the final stage under variable back pressure conditions to ensure Q 入 If the minimum allowable cooling flow rate is above the limit, then proceed to step S5; S5. Control the back pressure machine to operate according to the set back pressure setting value.

[0007] It should be further noted that in step S1, the minimum allowable flow rate Q under rated back pressure min The method of obtaining it is: The minimum inlet steam flow rate required for the back pressure compressor to operate under rated back pressure is determined based on the manufacturer's design parameters; this minimum allowable flow rate Q under rated back pressure is defined as follows. min .

[0008] It should be further noted that in step S1, the inlet steam flow rate Q 入 Inlet pressure P 入 and exhaust pressure P 排 The method of obtaining it is: An inlet steam flow detection device is installed on the inlet steam pipe of the back pressure machine, and the detection result is the inlet steam flow rate Q. 入 ; An inlet pressure detection device is installed on the inlet steam pipe of the back pressure machine; the detection result is the inlet pressure P. 入 ; An exhaust pressure detection device is installed on the exhaust pipe of the back pressure machine; the detection result is the exhaust pressure P. 排 .

[0009] It should be further noted that there are three inlet steam flow detection devices, three inlet pressure detection devices, and three exhaust steam pressure detection devices. The median value of the three detection results for each device is taken as the final result.

[0010] It should be further noted that in step S2, P 安 It is 0.5 MPa.

[0011] It should be further noted that in step S4, the minimum cooling flow rate curve of the final stage under variable back pressure is the curve showing the relationship between back pressure and minimum inlet steam flow rate. The method for obtaining the minimum cooling flow rate curve of the final stage under variable back pressure is as follows: S401. Fix the inlet pressure of the back pressure machine, divide the back pressure of the back pressure machine into multiple test nodes, adjust the inlet steam flow of the back pressure machine at each test node, and construct multiple test conditions. S402. Under each set of test conditions, monitor the temperature of the last stage blade in real time. When the inlet steam flow rate is reduced to make the temperature of the last stage blade close to the maximum allowable temperature of the last stage blade, record the back pressure value and the inlet steam flow rate value under the current conditions. The inlet steam flow rate value is the minimum inlet steam flow rate under the corresponding back pressure. S403. Fit the experimental data obtained in step S402 to obtain the curve of the relationship between the back pressure of the back pressure machine and the minimum inlet steam flow rate, which is the minimum cooling flow rate curve of the final stage under the variable back pressure condition.

[0012] It should be further noted that the method for obtaining the minimum cooling flow rate curve of the final stage under variable back pressure conditions is as follows: S411. Under different back pressure inlet pressures, the back pressure of the back pressure machine is divided into multiple test nodes. Under each test node, the steam flow rate at the inlet of the back pressure machine is adjusted to construct multiple test conditions under different inlet pressures. S412. First, under an inlet pressure, test each set of test conditions and monitor the temperature of the last stage blade in real time. When the inlet steam flow rate is reduced to make the temperature of the last stage blade close to the maximum allowable temperature of the last stage blade, record the back pressure value and the inlet steam flow rate value under the current condition. The inlet steam flow rate value is the minimum inlet steam flow rate under the corresponding back pressure. After completing the test of all back pressures at one inlet pressure, switch to the next inlet pressure and repeat the above operation to obtain the data of back pressure and minimum inlet steam flow rate at each inlet pressure; S413. Fit the experimental data obtained in step S412 to generate curve branches of back pressure and minimum inlet steam flow corresponding to each inlet pressure. Integrate all curve branches to obtain the corresponding curve of back pressure and minimum inlet steam flow of the back pressure machine, which is the minimum cooling flow curve of the last stage under variable back pressure conditions.

[0013] It should be further explained that step S6 is also included: adding an electric steam compressor at the end of the branch user supply of the back pressure machine exhaust steam, and pressurizing the exhaust steam through the electric steam compressor based on the user's actual steam pressure demand.

[0014] Secondly, the present invention also provides a back-compressor steam supply operation control system adapted to wide load conditions, for implementing the above-mentioned back-compressor steam supply operation control method adapted to wide load conditions, comprising: The parameter acquisition module is used to obtain the inlet steam flow rate Q of the back pressure turbine. 入 Rated back pressure allows minimum flow rate Q min Inlet pressure P 入 and exhaust pressure P 排 ; The differential pressure calculation and back pressure setting module is used to calculate the differential pressure based on P. 入 With P 排Calculate the pressure difference and set the back pressure setpoint; The flow rate comparison and back pressure setting module is used to compare Q. 入 and Q min The magnitude relationship is determined, and the back pressure setting value is set. The control module is used to control the back pressure machine to operate according to the set back pressure value.

[0015] Thirdly, the present invention provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the above-described back-pressure turbine steam supply operation control method adapted to wide load conditions.

[0016] The beneficial effects of this invention are as follows: The control method provided by this invention can dynamically adapt to back pressure under wide load conditions, solving the problem that it is difficult to maintain stable back pressure in the low load section of traditional operation mode. It ensures that the back pressure machine can operate stably under different loads, while avoiding the risk of exhaust temperature rise and last stage blade overheating due to insufficient flow, thus ensuring the safe operation of the back pressure machine.

[0017] The entire control process of this invention does not require frequent start-stop of the back pressure machine. The back pressure machine can be continuously operated by dynamically adjusting the back pressure setpoint, which reduces the number of start-stop cycles. This avoids the energy-saving effect reduction caused by frequent start-stop cycles, reduces equipment wear, and extends the safe service life of the back pressure machine. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a flowchart of a back-pressure turbine steam supply operation control method adapted to wide load conditions according to an embodiment of the present invention.

[0020] Figure 2 This is a curve of the minimum cooling flow rate of the final stage under variable back pressure conditions, obtained in the back pressure turbine steam supply operation control method adapted to wide load conditions according to an embodiment of the present invention.

[0021] Figure 3 This is a schematic block diagram of a back-pressure turbine steam supply operation control system adapted to wide load conditions, according to an embodiment of the present invention.

[0022] Figure 4 This is a schematic diagram of the hardware structure of an electronic device according to an embodiment of the present invention. Detailed Implementation

[0023] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0024] The following describes in detail the back-compressor steam supply operation control method adapted to wide load conditions according to the present invention. Specific details, such as particular system structures and techniques, are presented for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of the invention. However, those skilled in the art will understand that the invention can also be implemented in other embodiments without these specific details.

[0025] In the back-compression turbine steam supply operation control method adapted to wide load conditions disclosed in this invention, the term "comprising" indicates the presence of the described feature, integral, step, operation, element, and / or component, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or collections thereof. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0026] To facilitate a clear description of the technical solution of this invention, the terms "first" and "second" are used to distinguish identical or similar items with essentially the same function and effect. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, and that "first" and "second" are not necessarily different.

[0027] The terms "one embodiment" or "some embodiments" used in this invention mean that one or more embodiments of the invention include the specific features, structures, or characteristics described in that embodiment. Therefore, the terms "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of the invention do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized.

[0028] In this invention, "MPa.a" represents absolute pressure, which is the pressure expressed with absolute vacuum as the reference, that is, the actual pressure that the object bears.

[0029] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0030] The back-pressure turbine steam supply operation control method adapted to wide load conditions provided in this embodiment of the invention is executed by computer equipment. Correspondingly, the back-pressure turbine steam supply operation control system adapted to wide load conditions runs in the computer equipment.

[0031] Figure 1 This is a flowchart of a back-pressure turbine steam supply operation control method adapted to wide load conditions, according to an embodiment of the present invention. Figure 1 The executing entity can be a back-pressure turbine steam supply operation control system adapted to a wide range of load conditions. Depending on different requirements, the order of steps in this flowchart can be changed, and some steps can be omitted.

[0032] like Figure 1 As shown, the back-pressure turbine steam supply operation control method adapted to wide load conditions includes: Step S1: Obtain the inlet steam flow rate Q of the back pressure unit. 入 Rated back pressure allows minimum flow rate Q min Inlet pressure P 入 and exhaust pressure P 排 .

[0033] In some specific embodiments, in step S1, the minimum allowable flow rate Q under rated back pressure is... min The method of obtaining it is: The minimum inlet steam flow rate required for the back pressure compressor to operate under rated back pressure is determined based on the manufacturer's design parameters; this minimum allowable flow rate Q under rated back pressure is defined as follows. min .

[0034] In some specific embodiments, in step S1, the inlet steam flow rate Q 入 Inlet pressure P 入 and exhaust pressure P 排 The method of obtaining it is: An inlet steam flow detection device is installed on the inlet steam pipe of the back pressure machine, and the detection result is the inlet steam flow rate Q. 入 ; An inlet pressure detection device is installed on the inlet steam pipe of the back pressure machine; the detection result is the inlet pressure P. 入 ; An exhaust pressure detection device is installed on the exhaust pipe of the back pressure machine; the detection result is the exhaust pressure P. 排 .

[0035] In some specific embodiments, there are three inlet steam flow detection devices, three inlet pressure detection devices, and three exhaust steam pressure detection devices, and the median value of the three detection results of each detection device is taken as the final result.

[0036] Step S2, according to P 入 With P排 Calculate the pressure difference; if the pressure difference is less than the safe pressure difference P... 安 Set the back pressure setting to P. 入 -P 安 Then proceed to step S5; Otherwise, proceed to step S3.

[0037] In some specific embodiments, in step S2, P 安 It is 0.5 MPa.

[0038] Step S3, compare Q 入 and Q min The size relationship, if Q 入 ≥Q min Set the back pressure setting value to the rated back pressure of the back pressure machine, and then proceed to step S5; Otherwise, proceed to step S4.

[0039] Step S4: Adjust the back pressure setpoint according to the minimum cooling flow rate curve of the final stage under variable back pressure conditions to ensure Q 入 If the minimum allowable cooling flow rate is above the limit, then proceed to step S5.

[0040] In some specific embodiments, in step S4, the minimum cooling flow rate curve of the final stage under variable back pressure is a curve showing the relationship between back pressure and minimum inlet steam flow rate. The method for obtaining the minimum cooling flow rate curve of the final stage under variable back pressure can be as follows: S401. Fix the inlet pressure of the back pressure machine, divide the back pressure of the back pressure machine into multiple test nodes, adjust the inlet steam flow of the back pressure machine at each test node, and construct multiple test conditions. S402. Under each set of test conditions, monitor the temperature of the last stage blade in real time. When the inlet steam flow rate is reduced to make the temperature of the last stage blade close to the maximum allowable temperature of the last stage blade, record the back pressure value and the inlet steam flow rate value under the current conditions. The inlet steam flow rate value is the minimum inlet steam flow rate under the corresponding back pressure. S403. Fit the experimental data obtained in step S402 to obtain the curve of the relationship between the back pressure of the back pressure machine and the minimum inlet steam flow rate, which is the minimum cooling flow rate curve of the final stage under the variable back pressure condition.

[0041] In some specific embodiments, the method for obtaining the minimum cooling flow rate curve of the final stage under variable back pressure conditions can also be as follows: S411. Under different back pressure inlet pressures, the back pressure of the back pressure machine is divided into multiple test nodes. Under each test node, the steam flow rate at the inlet of the back pressure machine is adjusted to construct multiple test conditions under different inlet pressures. S412. First, under an inlet pressure, test each set of test conditions and monitor the temperature of the last stage blade in real time. When the inlet steam flow rate is reduced to make the temperature of the last stage blade close to the maximum allowable temperature of the last stage blade, record the back pressure value and the inlet steam flow rate value under the current condition. The inlet steam flow rate value is the minimum inlet steam flow rate under the corresponding back pressure. After completing the test of all back pressures under one inlet pressure, switch to the next inlet pressure and repeat the above operation to obtain the data coordinates (back pressure, minimum inlet steam flow) of back pressure and minimum inlet steam flow under each inlet pressure. S413. Fit the experimental data obtained in step S412 to generate curve branches of back pressure and minimum inlet steam flow corresponding to each inlet pressure. Integrate all curve branches to obtain the corresponding curve of back pressure and minimum inlet steam flow of the back pressure machine, which is the minimum cooling flow curve of the last stage under variable back pressure conditions.

[0042] Figure 2 The minimum cooling flow rate curve of the final stage of the B25-4.93 / 2.0 back-pressure turbine under variable back-pressure conditions is shown. It includes six curve branches, corresponding to inlet pressures of 4.87 MPa.a, 4.21 MPa.a, 3.69 MPa.a, 3.12 MPa.a, 2.86 MPa.a, and 2.34 MPa.a. In obtaining this minimum cooling flow rate curve under variable back-pressure conditions, the back pressure was divided into eight test nodes: 2 MPa.a, 1.8 MPa.a, 1.5 MPa.a, 1.2 MPa.a, 0.9 MPa.a, 0.5 MPa.a, 0.3 MPa.a, and 0.09803 MPa.a. Tests were performed at each test node under various inlet pressures to obtain the minimum inlet steam flow rate corresponding to that node, which was then fitted to the curve.

[0043] Step S5: Control the back pressure machine to operate according to the set back pressure setting value.

[0044] Step S6: Add an electric steam compressor to the end of the branch user supply of the back pressure turbine exhaust steam, and pressurize the exhaust steam through the electric steam compressor based on the user's actual steam pressure requirements.

[0045] In one specific embodiment, the back-compression turbine steam supply operation control method adapted to wide load conditions includes the following steps: S1. Obtain the inlet steam flow rate Q of the back pressure unit. 入 Rated back pressure allows minimum flow rate Q min Inlet pressure P 入 and exhaust pressure P 排 ; S2, according to P 入 With P 排Calculate the pressure difference; if the pressure difference is less than the safe pressure difference P... 安 Set the back pressure setting to P. 入 -P 安 Then proceed to step S5; Otherwise, proceed to step S3; S3, Comparison Q 入 and Q min The size relationship, if Q 入 ≥Q min Set the back pressure setting value to the rated back pressure of the back pressure machine, and then proceed to step S5; Otherwise, proceed to step S4; S4. Adjust the back pressure setpoint according to the minimum cooling flow rate curve of the final stage under variable back pressure conditions to ensure Q 入 If the minimum allowable cooling flow rate is above the limit, then proceed to step S5; S5. Control the back pressure machine to operate according to the set back pressure setting value.

[0046] The following are embodiments of the back-compressor steam supply operation control system adapted to wide load conditions provided by the present invention. This back-compressor steam supply operation control system adapted to wide load conditions and the back-compressor steam supply operation control method adapted to wide load conditions in the above embodiments belong to the same inventive concept. For details not described in detail in the embodiments of the back-compressor steam supply operation control system adapted to wide load conditions, please refer to the embodiments of the back-compressor steam supply operation control method adapted to wide load conditions described above.

[0047] like Figure 3 As shown, the back-pressure turbine steam supply operation control system adapted to wide load conditions includes: The parameter acquisition module is used to obtain the inlet steam flow rate Q of the back pressure turbine. 入 Rated back pressure allows minimum flow rate Q min Inlet pressure P 入 and exhaust pressure P 排 ; The differential pressure calculation and back pressure setting module is used to calculate the differential pressure based on P. 入 With P 排 Calculate the pressure difference and set the back pressure setpoint; The flow rate comparison and back pressure setting module is used to compare Q. 入 and Q min The magnitude relationship is determined, and the back pressure setting value is set. The control module is used to control the back pressure machine to operate according to the set back pressure value.

[0048] The back-pressure turbine steam supply operation control system adapted to wide load conditions in this embodiment is used to realize the back-pressure turbine steam supply operation control method adapted to wide load conditions.

[0049] The present invention also provides an electronic device for implementing the various embodiments of the present invention. Figure 4 A hardware structure diagram of an electronic device to implement various embodiments of the present invention is shown below. Figure 4 As shown, the electronic device includes a memory, a processor, and a computer program stored in the memory and capable of running on the processor.

[0050] Those skilled in the art will understand that the electronic device structure involved in the embodiments of the present invention does not constitute a limitation on the electronic device. The electronic device may include more or fewer components than shown in the figure, or combine certain components, or have different component arrangements.

[0051] In embodiments of the invention, electronic devices include, but are not limited to, laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. Electronic devices may also represent various forms of mobile devices and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the embodiments of the invention described and / or claimed herein.

[0052] In embodiments of the present invention, the processor may be implemented using at least one of an Application-Specific Integrated Circuit (ASIC), a Digital Signal Processor (DSP), a Digital Signal Processing Device (DSPD), a processor, a controller, a microcontroller, a microprocessor, or an electronic unit designed to perform the functions described herein. In some cases, such implementations may be implemented within a controller. For software implementations, implementations such as processes or functions may be implemented with separate software modules that allow the performance of at least one function or operation. The software code may be implemented by a software application (or program) written in any suitable programming language, and the software code may be stored in memory and executed by the controller.

[0053] In addition, the electronic device includes some functional modules not shown, which will not be described in detail here.

[0054] Those skilled in the art will understand that the various aspects of the electronic device provided by this invention can be implemented as a system, method, or program product. Therefore, the various aspects of this invention can be specifically implemented in the following forms: a completely hardware implementation, a completely software implementation (including firmware, microcode, etc.), or a combination of hardware and software aspects, collectively referred to herein as a "circuit," "module," or "system."

[0055] Example 1 The back pressure of the B25-4.93 / 2.0 type back pressure turbine is regulated using the steam supply operation control method adapted to wide load conditions of the present invention. The maximum power of the back pressure turbine is 25MW, the rated inlet steam pressure is 4.93MPa.a, and the rated back pressure is 2.0MPa.a. The specific process is as follows: Three inlet steam flow detection devices and three inlet pressure detection devices are installed on the inlet steam pipe of the back pressure compressor, and three exhaust pressure detection devices are installed on the exhaust steam pipe of the back pressure compressor. The inlet steam flow, inlet pressure, and exhaust pressure are detected by the three sets of devices respectively. The median value of each set of detection results is taken to obtain the inlet steam flow Q. 入 =170t / h, inlet pressure P 入 =2.34MPa.a, exhaust pressure P 排 =1.90MPa.a; Based on the factory design parameters of this back pressure machine, determine its rated back pressure minimum allowable flow rate Q. min =163t / h.

[0056] P was calculated 入 With P 排 The pressure difference is 2.34 MPa.a - 1.90 MPa.a = 0.44 MPa, and the safe pressure difference P 安 =0.5MPa, since 0.44MPa < 0.5MPa, set the back pressure setting to P. 入 -P 安 , that is, 2.34MPa.a-0.5MPa=1.84MPa.a.

[0057] The back pressure unit is controlled to operate at a back pressure setpoint of 1.84 MPa to ensure stable operation and steam supply.

[0058] Example 2 The steam supply operation control method adapted to wide load conditions of the present invention is used to regulate the back pressure of a back compressor whose extraction steam source is from the reheat steam hot section. The specific process is as follows: Three inlet steam flow detection devices and three inlet pressure detection devices are installed on the inlet steam pipe of the back pressure compressor, and three exhaust pressure detection devices are installed on the exhaust steam pipe of the back pressure compressor. The inlet steam flow, inlet pressure, and exhaust pressure are detected by the three sets of devices respectively. The median value of each set of detection results is taken to obtain the inlet steam flow Q. 入 =149.7t / h, inlet pressure P 入 =3.12MPa.a, exhaust pressure P 排 =1.75MPa.a; Based on the factory design parameters of this back pressure unit, determine its rated back pressure minimum allowable flow rate Q. min =163t / h.

[0059] P was calculated 入 With P 排 The pressure difference is 3.12 MPa.a - 1.75 MPa.a = 1.37 MPa, which is different from the safe pressure difference P. 安 =0.5MPa comparison, since 1.37MPa>0.5MPa.

[0060] Compare Q 入 and Q min Given the relationship between the magnitudes, since 149.7t / h < 163t / h, based on the plotted curve showing the correspondence between back pressure and minimum inlet steam flow (the curve of minimum cooling flow in the final stage under variable back pressure conditions), find the point on the curve corresponding to the actual inlet steam flow, read the corresponding abscissa (maximum back pressure value), and adjust the back pressure setpoint to be ≤ this maximum back pressure value. Specific steps include: (1) The back pressure inlet pressure is fixed at 3.12 MPa.a, which is consistent with the current operating inlet pressure. By adjusting the exhaust valve of the back pressure, the back pressure is divided into 8 test nodes: 2.0 MPa.a, 1.8 MPa.a, 1.5 MPa.a, 1.2 MPa.a, 0.9 MPa.a, 0.5 MPa.a, 0.3 MPa.a and 0.098 MPa.a. At each test node, the inlet valve is adjusted to reduce the inlet steam flow, and multiple test conditions are constructed.

[0061] (2) Under each set of test conditions, the temperature of the last stage blade is monitored in real time by a temperature detection device. When the inlet steam flow rate is reduced to the point that the temperature of the last stage blade is close to the maximum allowable temperature of the last stage blade, the back pressure value and the inlet steam flow rate value under the current conditions are recorded. All test conditions are monitored in this way to obtain multiple sets of back pressure-minimum inlet steam flow rate data.

[0062] (3) Perform polynomial fitting on the obtained experimental data to obtain the curve of the relationship between back pressure and minimum inlet steam flow, that is, the curve of minimum cooling flow of the last stage under variable back pressure.

[0063] (4) Find the point with a vertical axis (inlet steam flow rate) of 149.7t / h on the minimum cooling flow rate curve of the last stage under the variable back pressure condition. It is found that the horizontal axis (maximum back pressure value) corresponding to this point is 1.8MPa.a. Adjust the back pressure machine setting value to a value ≤1.8MPa.a, for example, 1.8MPa.a.

[0064] The back pressure unit is controlled to operate at a back pressure setpoint of 1.8 MPa to ensure stable operation and steam supply.

[0065] Example 3 The steam supply operation control method adapted to wide load conditions of the present invention is used to regulate the back pressure of a back compressor whose extraction steam source is from the reheat steam hot section. The specific process is as follows: Three inlet steam flow detection devices and three inlet pressure detection devices are installed on the inlet steam pipe of the back pressure compressor, and three exhaust pressure detection devices are installed on the exhaust steam pipe of the back pressure compressor. The inlet steam flow, inlet pressure, and exhaust pressure are detected by the three sets of devices respectively. The median value of each set of detection results is taken to obtain the inlet steam flow Q. 入 =168.1t / h, inlet pressure P 入 =3.74 MPa.a, exhaust pressure P 排 =1.89MPa.a; Based on the factory design parameters of this back pressure unit, determine its rated back pressure minimum allowable flow rate Q. min =163t / h.

[0066] P was calculated 入 With P 排 The pressure difference is 3.74 MPa.a - 1.89 MPa.a = 1.85 MPa, which is different from the safe pressure difference P. 安 =0.5MPa comparison, since 1.85MPa > 0.5MPa, continue comparing Q. 入 and Q min Given the relationship between the magnitudes, since 168.1t / h > 163t / h, the back pressure setting value is set to the rated back pressure of the back pressure machine, 2.0MPa.a.

[0067] The back pressure compressor is controlled to operate at a back pressure setpoint of 2.0 MPa to ensure stable operation and steam supply.

[0068] Although the present invention has been described in detail with reference to the accompanying drawings and preferred embodiments, the present invention is not limited thereto. Various equivalent modifications or substitutions can be made to the embodiments of the present invention by those skilled in the art without departing from the spirit and essence of the invention, and such modifications or substitutions should all be within the scope of the present invention. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should also be covered within the protection scope of the present invention.

Claims

1. A back-pressure turbine steam supply operation control method adaptable to wide load conditions, characterized in that, Includes the following steps: S1. Obtain the inlet steam flow rate Q of the back pressure unit. 入 Rated back pressure allows minimum flow rate Q min Inlet pressure P 入 and exhaust pressure P 排 ; S2, according to P 入 With P 排 Calculate the pressure difference; if the pressure difference is less than the safe pressure difference P... 安 Set the back pressure setting to P. 入 -P 安 Then proceed to step S5; Otherwise, proceed to step S3; S3, Comparison Q 入 and Q min The size relationship, if Q 入 ≥Q min Set the back pressure setting value to the rated back pressure of the back pressure machine, and then proceed to step S5; Otherwise, proceed to step S4; S4. Adjust the back pressure setpoint according to the minimum cooling flow rate curve of the final stage under variable back pressure conditions to ensure Q 入 If the minimum allowable cooling flow rate is above the limit, then proceed to step S5; S5. Control the back pressure machine to operate according to the set back pressure setting value.

2. The back-pressure turbine steam supply operation control method adapted to wide load conditions as described in claim 1, characterized in that, In step S1, the minimum allowable flow rate Q under rated back pressure min The method of obtaining it is: The minimum inlet steam flow rate required for the back pressure compressor to operate under rated back pressure is determined based on the manufacturer's design parameters; this minimum allowable flow rate Q under rated back pressure is defined as follows. min。 3. The back-pressure turbine steam supply operation control method adapted to wide load conditions as described in claim 1, characterized in that, In step S1, the inlet steam flow rate Q 入 Inlet pressure P 入 and exhaust pressure P 排 The method of obtaining it is: An inlet steam flow detection device is installed on the inlet steam pipe of the back pressure machine, and the detection result is the inlet steam flow rate Q. 入 ; An inlet pressure detection device is installed on the inlet steam pipe of the back pressure machine; the detection result is the inlet pressure P. 入 ; An exhaust pressure detection device is installed on the exhaust pipe of the back pressure machine; the detection result is the exhaust pressure P. 排 .

4. The back-pressure turbine steam supply operation control method adapted to wide load conditions as described in claim 3, characterized in that, There are three inlet steam flow detection devices, three inlet pressure detection devices, and three exhaust steam pressure detection devices. The median value of the three detection results for each device is taken as the final result.

5. The back-pressure turbine steam supply operation control method adapted to wide load conditions as described in claim 1, characterized in that, In step S4, the minimum cooling flow rate curve of the final stage under variable back pressure is the curve showing the relationship between back pressure and minimum inlet steam flow rate.

6. The back-pressure turbine steam supply operation control method adapted to wide load conditions as described in claim 5, characterized in that, The method for obtaining the minimum cooling flow rate curve of the final stage under variable back pressure conditions is as follows: S401. Fix the inlet pressure of the back pressure machine, divide the back pressure of the back pressure machine into multiple test nodes, adjust the inlet steam flow of the back pressure machine at each test node, and construct multiple test conditions. S402. Under each set of test conditions, monitor the temperature of the last stage blade in real time. When the inlet steam flow rate is reduced to make the temperature of the last stage blade close to the maximum allowable temperature of the last stage blade, record the back pressure value and the inlet steam flow rate value under the current conditions. The inlet steam flow rate value is the minimum inlet steam flow rate under the corresponding back pressure. S403. Fit the experimental data obtained in step S402 to obtain the curve of the relationship between the back pressure of the back pressure machine and the minimum inlet steam flow rate, which is the minimum cooling flow rate curve of the final stage under the variable back pressure condition.

7. The back-pressure turbine steam supply operation control method adapted to wide load conditions as described in claim 5, characterized in that, The method for obtaining the minimum cooling flow rate curve of the final stage under variable back pressure conditions is as follows: S411. Under different back pressure inlet pressures, the back pressure of the back pressure machine is divided into multiple test nodes. Under each test node, the steam flow rate at the inlet of the back pressure machine is adjusted to construct multiple test conditions under different inlet pressures. S412. First, under an inlet pressure, test each set of test conditions and monitor the temperature of the last stage blade in real time. When the inlet steam flow rate is reduced to make the temperature of the last stage blade close to the maximum allowable temperature of the last stage blade, record the back pressure value and the inlet steam flow rate value under the current condition. The inlet steam flow rate value is the minimum inlet steam flow rate under the corresponding back pressure. After completing the test of all back pressures at one inlet pressure, switch to the next inlet pressure and repeat the above operation to obtain the data of back pressure and minimum inlet steam flow rate at each inlet pressure; S413. Fit the experimental data obtained in step S412 to generate curve branches of back pressure and minimum inlet steam flow corresponding to each inlet pressure. Integrate all curve branches to obtain the corresponding curve of back pressure and minimum inlet steam flow of the back pressure machine, which is the minimum cooling flow curve of the last stage under variable back pressure conditions.

8. The back-pressure turbine steam supply operation control method adapted to wide load conditions as described in any one of claims 1 to 7, characterized in that, It also includes step S6, adding an electric steam compressor at the end of the branch user supply of the back pressure machine exhaust steam, and pressurizing the exhaust steam through the electric steam compressor based on the user's actual steam pressure demand.

9. A back-pressure turbine steam supply operation control system adaptable to wide load conditions, characterized in that, The method for controlling the steam supply operation of a back-pressure turbine adapted to wide load conditions as described in claim 1 includes: The parameter acquisition module is used to obtain the inlet steam flow rate Q of the back pressure turbine. 入 Rated back pressure allows minimum flow rate Q min Inlet pressure P 入 and exhaust pressure P 排 ; The differential pressure calculation and back pressure setting module is used to calculate the differential pressure based on P. 入 With P 排 Calculate the pressure difference and set the back pressure setpoint; The flow rate comparison and back pressure setting module is used to compare Q. 入 and Q min The magnitude relationship is determined, and the back pressure setting value is set. The control module is used to control the back pressure machine to operate according to the set back pressure value.

10. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes a computer program, it implements the steps of the back-pressure turbine steam supply operation control method adapted to wide load conditions as described in claim 1.

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