An air compression system of a thermal power plant, a control method and device of the air compression system of the thermal power plant, and a storage medium

Abstract

The application provides a thermal power plant air compression system, a control method and device of the thermal power plant air compression system and a storage medium, relates to the technical field of air compression, and can configure different compressors according to the operation cycle of a thermal power plant to meet the requirements of air compression stability and energy saving in the whole cycle of the thermal power plant. The system comprises: a plurality of screw air compressors configured to switch between loading and unloading operation states according to instructions; a plurality of centrifugal air compressors configured to continuously operate; a gas supply main pipe configured to supply the gas output by the centrifugal air compressors and the screw air compressors to a gas using device; and a controller configured to control the screw air compressors to adjust the loading and unloading operation states according to the adjustment instructions of the screw air compressors based on the gas pressure output by the centrifugal air compressors. The plurality of screw air compressors are built after the completion of a first construction cycle, the plurality of centrifugal air compressors are built after the completion of a second construction cycle, and the completion time of the first construction cycle is earlier than that of the second construction cycle.

Description

Technical Field

[0001] This application relates to the field of air compression technology, and in particular to an air compression system for a thermal power plant, a control method for the air compression system for a thermal power plant, an apparatus for the control method of the air compression system for a thermal power plant, and a storage medium. Background Technology

[0002] Compressed air systems are crucial auxiliary systems in thermal power plants, providing power to various air-consuming equipment such as thermal control instruments, pneumatic valves, ash removal and conveying systems, and equipment maintenance systems. With the continuous increase in the scale of thermal power units and the increasingly stringent environmental protection requirements, the demand for both the quantity and quality of compressed air in thermal power plants is also rising, resulting in an increasing proportion of compressed air system energy consumption in total plant electricity consumption.

[0003] Currently, in the multi-phase construction of thermal power plants, each phase often has its own independently designed compressed air system, resulting in redundant equipment configuration, resource waste, high system complexity, and a large workload for maintenance. Furthermore, existing compressed air systems are typically not designed to fully consider the differentiated needs of the compressed air system during the construction and operation phases, making it difficult to balance air supply reliability and operational economy throughout the entire lifecycle. Summary of the Invention

[0004] This application provides an air compression system for a thermal power plant, a control method for the air compression system, an apparatus for the control method, and a storage medium. Different compressor configurations can be made according to the operating cycle of the thermal power plant to balance the air supply stability and energy-saving requirements of the air compression system throughout the entire life cycle of the thermal power plant.

[0005] A first aspect of this application provides an air compression system for a thermal power plant, comprising: Multiple screw air compressors, wherein the screw air compressors are configured to switch loading and unloading operation states according to instructions; Multiple centrifugal air compressors, which are configured to operate continuously; A main gas pipeline is used to supply the gas output from the centrifugal air compressor and the screw air compressor to the gas-consuming equipment; The controller is used to output adjustment commands for the screw air compressor based on the gas pressure output by the centrifugal air compressor, so as to control the screw air compressor to adjust the loading and unloading operation status according to the adjustment commands; The centrifugal air compressors and screw air compressors were constructed in phases. The screw air compressors were completed after the first construction phase, and the centrifugal air compressors were completed after the second construction phase. The completion time of the first construction phase was earlier than the completion time of the second construction phase.

[0006] In some implementations, during the period when the first construction cycle has been completed and the second construction cycle has not been completed, all the screw air compressors built during the first construction cycle are used to supply air to the air-consuming equipment. After the second construction cycle is completed, the operation of some of the screw air compressors will be suspended.

[0007] In some embodiments, the gas transmission header includes a first gas transmission header and a second gas transmission header. The first gas transmission header is used to transmit a portion of the gas output from the centrifugal air compressor and the screw air compressor to the corresponding gas-consuming equipment. The second gas transmission header is used to transmit another portion of the gas output from the centrifugal air compressor and the screw air compressor to the corresponding gas-consuming equipment. The first gas supply main pipe is used to transmit compressed air for instruments, and the second gas supply main pipe is used to transmit gas for delivery and maintenance.

[0008] In some embodiments, the air compression system for the thermal power plant further includes: A combined dryer is installed between the first gas transmission header and the corresponding gas-using equipment; A compression heat regeneration adsorption dryer is installed between the second gas supply main pipe and the corresponding gas-using equipment.

[0009] In some embodiments, the air compression system for thermal power plants further includes: The gas supply main pipe air intake regulating device is used to adjust the air intake volume of the first gas supply main pipe and the second gas supply main pipe according to the gas pressure in the first gas supply main pipe, so as to regulate the air intake volume of the corresponding gas-using equipment.

[0010] A second aspect of this application provides a control method for an air compression system in a thermal power plant, applied to an air compression system in a thermal power plant as described in any of the first aspects above, the control method for the air compression system in a thermal power plant comprising: After the completion of the first and second construction cycles, multiple screw air compressors will be configured to switch loading and unloading operation states according to instructions, and multiple centrifugal air compressors will be configured to operate continuously. The gas output from the centrifugal air compressor and the screw air compressor is supplied to the gas-consuming equipment through the gas transmission header; The controller outputs adjustment commands to the screw air compressor based on the gas pressure output by the centrifugal air compressor, thereby controlling the screw air compressor to adjust its loading and unloading operation status according to the adjustment commands. The centrifugal air compressors and screw air compressors were constructed in phases, with the screw air compressors completed after the first construction cycle and the centrifugal air compressors completed after the second construction cycle. The completion time of the first construction cycle was earlier than the completion time of the second construction cycle.

[0011] In some embodiments, the control method for the air compression system of the thermal power plant further includes: During the period between the completion of the first construction cycle and the completion of the second construction cycle, all screw air compressors built during the first construction cycle are used to supply air to the air-consuming equipment. After the second construction cycle is completed, the operation of some of the screw air compressors will be suspended.

[0012] In some embodiments, the control method for the air compression system of the thermal power plant further includes: The target air delivery rate of the centrifugal air compressor is determined based on the actual guide vane opening of the centrifugal air compressor. Based on the target air delivery volume and the actual air delivery volume of the centrifugal air compressor, determine the aging degradation score of each centrifugal air compressor; If the aging degradation score is lower than a preset score threshold, the portion of the screw air compressor that was previously in operation will be started and an alarm message will be generated.

[0013] A third aspect of this application provides a control device for a thermal power plant air compression system, used to execute the control method for a thermal power plant air compression system as described in any of the second aspects above, wherein the control device for the thermal power plant air compression system includes: The operation configuration module is used to configure multiple screw air compressors to switch loading and unloading operation states according to instructions, and to configure multiple centrifugal air compressors to continuous operation state after the completion of the first construction cycle and the second construction cycle. A gas transmission module is used to supply gas output from the centrifugal air compressor and the screw air compressor to the gas-consuming equipment via a gas transmission header. The operation control module is used to output adjustment commands to the screw air compressor based on the gas pressure output by the centrifugal air compressor, so as to control the screw air compressor to adjust the loading and unloading operation status according to the adjustment commands; The centrifugal air compressors and screw air compressors were constructed in phases, with the screw air compressors completed after the first construction cycle and the centrifugal air compressors completed after the second construction cycle. The completion time of the first construction cycle was earlier than the completion time of the second construction cycle.

[0014] A fourth aspect of this application provides a storage medium storing a computer program that, when executed by a processor, implements the steps of the control method for the air compression system of a thermal power plant according to any of the second aspects described above.

[0015] This application provides an air compression system for a thermal power plant, a control method for the air compression system, an apparatus, and a storage medium. Since the energy efficiency ratio of centrifugal air compressors is lower than that of screw air compressors, multiple centrifugal air compressors are configured to operate continuously, and multiple screw air compressors are configured to switch loading and unloading operation states according to instructions. A main gas pipeline is provided to supply the gas output from the centrifugal and screw air compressors to the gas-consuming equipment. The controller outputs adjustment instructions to the screw air compressors based on the gas pressure output from the centrifugal air compressors to control the screw air compressors to adjust their loading and unloading operation states according to the adjustment instructions. This allows the centrifugal air compressors to continuously and efficiently supply air under base load, while the screw air compressors only adjust loading and unloading in real time according to the output fluctuations of the centrifugal compressors to compensate for any lag or insufficiency in centrifugal compressor adjustment. This reduces the operating power of the air compression system and further reduces the energy consumption required for air compression. By constructing multiple centrifugal and screw air compressors in phases, with the screw compressors completed in the first phase and the centrifugal compressors in the second phase, and the first phase completed before the second, the power plant can initially utilize the flexible and adaptable screw compressors to meet the needs of unit commissioning and trial operation during the initial construction phase. Once the power plant enters a stable operating period, high-efficiency centrifugal air compressors can be introduced as the primary air supply equipment. This shortens the construction time of the air compression system, allows for a smooth transition and upgrade of the power plant's air compression system from construction to operation, and simultaneously addresses the dual requirements of energy conservation, environmental protection, and high-quality air compression. Attached Figure Description

[0016] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A schematic structural diagram of an air compression system for a thermal power plant provided in this application embodiment; Figure 2 A schematic diagram of an air compression system for a thermal power plant provided for embodiments of this application; Figure 3 A schematic flowchart illustrating a control method for an air compression system in a thermal power plant, provided as an embodiment of this application; Figure 4 A schematic structural diagram of a control device for an air compression system in a thermal power plant, provided as an embodiment of this application; Figure 5 This is a schematic structural diagram of a storage medium provided in an embodiment of this application. Detailed Implementation

[0018] To better understand the technical solutions provided in the embodiments of this specification, the technical solutions of the embodiments of this specification will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of this specification and the specific features in the embodiments are detailed descriptions of the technical solutions of the embodiments of this specification, rather than limitations on the technical solutions of this specification. In the absence of conflict, the embodiments of this specification and the technical features in the embodiments can be combined with each other.

[0019] In this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, without necessarily requiring or implying any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. The term "two or more" includes two or more cases.

[0020] Figure 1 This is a schematic structural diagram of an air compression system for a thermal power plant, provided as an embodiment of this application. Figure 2 This is a schematic diagram of an air compression system for a thermal power plant, provided as an embodiment of this application. Figure 1 and Figure 2As shown, in a first aspect of this application, an air compression system for a thermal power plant is provided, comprising: multiple screw air compressors 101, multiple centrifugal air compressors 200, an air transmission header 300, and a controller. The screw air compressor 101 is configured to switch between loading and unloading operation states according to instructions; the centrifugal air compressor 200 is configured to operate continuously; the gas supply header 300 is used to supply the gas output from the centrifugal air compressor 101 and the screw air compressor 200 to the gas-consuming equipment; the controller is used to output adjustment instructions for the screw air compressor 101 according to the gas pressure output by the centrifugal air compressor 200, so as to control the screw air compressor 101 to adjust the loading and unloading operation state according to the adjustment instructions; the multiple centrifugal air compressors 200 and the multiple screw air compressors 101 are obtained through phased construction, and the multiple screw air compressors 101 are completed after the completion of the first construction cycle, and the multiple centrifugal air compressors 200 are completed after the completion of the second construction cycle. The completion time of the first construction cycle is earlier than the completion time of the second construction cycle.

[0021] For example, the volumetric flow rate of a centrifugal air compressor can be configured to 140 Nm³ / min, the discharge pressure can be configured to 0.75 MPa, and the power can be configured to 710 kW. The volumetric flow rate of a screw air compressor can be configured to 69.2 Nm³ / min, the discharge pressure can be configured to 0.75 MPa, and the power can be configured to 400 kW.

[0022] The air compression system for thermal power plants provided in this application embodiment, since the energy consumption ratio of centrifugal air compressors is lower than that of screw air compressors, can achieve this by configuring multiple centrifugal air compressors to operate continuously and multiple screw air compressors to switch loading and unloading operation states according to instructions. Simultaneously, a main gas supply pipe is provided to supply the gas output from both centrifugal and screw air compressors to the gas-consuming equipment. The controller outputs adjustment commands to the screw air compressors based on the gas pressure output from the centrifugal air compressors, controlling the screw air compressors to adjust their loading and unloading operation states accordingly. This allows the centrifugal air compressors to continuously and efficiently supply air under base load, while the screw air compressors only adjust their loading and unloading in real time based on fluctuations in centrifugal output to compensate for centrifugal adjustment lag or insufficiency. This reduces the operating power of the air compression system and further reduces the energy consumption required for air compression. By constructing multiple centrifugal and screw air compressors in phases, with the screw compressors completed in the first phase and the centrifugal compressors in the second phase, and the first phase completed before the second, the power plant can initially utilize the flexible and adaptable screw compressors to meet the needs of unit commissioning and trial operation during the initial construction phase. Once the power plant enters a stable operating period, high-efficiency centrifugal air compressors can be introduced as the primary air supply equipment. This shortens the construction time of the air compression system, allows for a smooth transition and upgrade of the power plant's air compression system from construction to operation, and simultaneously addresses the dual requirements of energy conservation, environmental protection, and high-quality air compression.

[0023] like Figure 1 As shown, in some feasible implementations, during the period between the completion of the first construction cycle and the completion of the second construction cycle, all screw air compressors built during the first construction cycle are used to supply air to air-consuming equipment; after the completion of the second construction cycle, some screw air compressors are suspended from operation. Here, all screw air compressors built during the first construction cycle are represented by 100, screw air compressors still in operation after the completion of the second construction cycle are represented by 101, and screw air compressors suspended from operation after the completion of the second construction cycle are represented by 102.

[0024] The air compression system for thermal power plants provided in this application embodiment utilizes all screw air compressors built during the first construction cycle (during which the first construction cycle is completed and the second construction cycle is not yet completed) to supply air to air-consuming equipment. This allows the thermal power plant to flexibly adjust the air supply by loading and unloading all screw air compressors during the initial construction phase, when the air load is unstable and centrifugal air compressors are not yet operational. This ensures a sufficient supply of compressed air during unit commissioning and trial operation, meeting the high-quality air demand of the thermal power plant in the early stages of construction. By suspending the operation of some screw air compressors after the completion of the second construction cycle, newly added high-efficiency centrifugal air compressors can assume the base load air supply, while some screw air compressors that were originally running continuously can be converted to standby. This improves air compression efficiency, reduces air compression energy consumption, and reduces compressor usage, achieving a smooth transition and system upgrade of the thermal power plant's air compression system from the construction phase to the operation phase.

[0025] In some feasible implementations, the gas transmission header includes a first gas transmission header and a second gas transmission header. The first gas transmission header is used to transmit a portion of the gas output from the centrifugal air compressor and the screw air compressor to the corresponding gas-consuming equipment. The second gas transmission header is used to transmit another portion of the gas output from the centrifugal air compressor and the screw air compressor to the corresponding gas-consuming equipment. The first gas transmission header is used to transmit instrument compressed air, and the second gas transmission header is used to transmit delivery gas and maintenance gas.

[0026] It should be noted that instrument compressed air is the type of air used in thermal power plants with the highest quality requirements. It is primarily used as the working air source for precision control equipment such as thermal control instruments, pneumatic valves, pneumatic actuators, and electric positioners. Therefore, the pressure of the instrument air system must be absolutely stable, undisturbed, and capable of continuous and safe operation. If the supply of instrument compressed air is interrupted or its quality deteriorates, it may damage pneumatic valve control positioners and pneumatic components. This could result in equipment malfunctions or failures to operate, or even unplanned unit shutdowns. The quality requirements for instrument compressed air are: pressure dew point -40℃, oil content less than 1 mg / m³, and dust particle size less than or equal to 3 μm.

[0027] It should be noted that maintenance air and conveying air usually share the same air supply system. Conveying air refers to compressed air used for the pneumatic conveying of various materials in process applications. In thermal power plants, this is typically the specialized conveying air for ash removal, used to transport fly ash from electrostatic precipitators and economizer ash hoppers to ash silos via closed pipelines. Maintenance air refers to compressed air used for maintenance and operation in thermal power plants, used to drive pneumatic tools such as pneumatic wrenches for equipment disassembly and assembly, to blow dust and debris off pipelines and equipment surfaces, and to provide power for equipment maintenance. For both conveying and maintenance air, the quality requirements are: pressure dew point 2°C, oil content less than 5 ppm, and dust particle size less than or equal to 3 μm.

[0028] The air compression system for thermal power plants provided in this application embodiment includes a first air transmission header and a second air transmission header. The first air transmission header transmits a portion of the gas output from centrifugal and screw air compressors to the corresponding air-consuming equipment, providing instrument compressed air for these equipment. The second air transmission header transmits another portion of the gas output from the centrifugal and screw air compressors to the corresponding air-consuming equipment, providing conveying and maintenance compressed air for these equipment. This allows instrument equipment in the thermal power plant, such as thermal control instruments and pneumatic valves, which have strict air quality requirements, to obtain high-quality compressed air through the first air transmission header. Simultaneously, auxiliary equipment, such as ash removal and conveying, and maintenance purging, which have relatively lower air quality requirements, can obtain general-quality compressed air through the second air transmission header, achieving tiered and categorized air supply to different air-consuming equipment. Furthermore, by using separate main pipelines to transmit instrument compressed air, delivery air, and maintenance air, it is possible to avoid applying the same high-quality treatment standards to delivery air and maintenance air as to instrument compressed air. This reduces energy consumption and processing costs in the post-processing stage. While ensuring that the air supply quality of various air-using equipment meets their respective operating requirements, it effectively reduces energy consumption in the compressed air post-processing stage and improves the overall economic efficiency of the compressed air system.

[0029] In some feasible implementations, the air compression system of a thermal power plant further includes: a combined dryer, installed between the first air supply header and the corresponding air-consuming equipment; and a compression heat regeneration adsorption dryer, installed between the second air supply header and the corresponding air-consuming equipment.

[0030] For example, the volumetric flow rate of the combined dryer can be configured to 80 Nm³ / min and the exhaust pressure can be configured to 0.75 MPa. The combined dryer may include a refrigerated dryer and an adsorption dryer. The volumetric flow rate of the compression heat regeneration adsorption dryer can be configured to 150 Nm³ / min and the exhaust pressure can be configured to 0.75 MPa.

[0031] It should be noted that combined dryers include refrigerated dryers and adsorption dryers. Refrigerated dryers use refrigeration equipment to forcibly cool compressed air, causing water vapor in the air to condense into water droplets and precipitate out. They have the advantages of no air loss and low energy consumption. Adsorption dryers use adsorbents such as molecular sieves to filter saturated water vapor in compressed air, lowering the dew point to a lower temperature, but requiring more air for regeneration. Combined dryers combine refrigerated and adsorption dryers to maximize the advantages of both. Compressed air first enters the refrigerated dryer, where it is cooled by heat exchange and then enters the evaporator for further cooling. This causes most of the gaseous moisture to condense into liquid water, which is then separated and discharged. The compressed air, after being treated in the refrigeration section, then enters the adsorption dryer for deep drying, further removing residual moisture and resulting in finished air with a lower dew point and higher quality.

[0032] It should be noted that the compression heat regeneration adsorption dryer is an adsorption drying device that uses the high-temperature exhaust heat from an air compressor to directly heat the regenerated desiccant. The adsorbent adsorbs moisture at room temperature and high vapor pressure. During the regeneration process, the high-temperature exhaust gas from the air compressor is used as the regeneration gas and enters the drying tower. The adsorbed moisture is released from the adsorbent and carried out of the drying tower by the thermal diffusion effect of the hot air. Because the compression heat regeneration adsorption dryer directly utilizes the heat of compression generated during the air compressor compression process for regeneration, there is no need for an additional electric heater like in a micro-heat regeneration dryer. Furthermore, the heating and regeneration process does not consume additional finished compressed air, resulting in extremely low energy consumption and operating costs.

[0033] The air compression system for thermal power plants provided in this application embodiment uses a combined dryer installed between the first air supply header and the corresponding air-consuming equipment, and a compression heat regeneration adsorption dryer installed between the second air supply header and the corresponding air-consuming equipment. This allows the instrument compressed air transmitted through the first air supply header to reach a high-quality state that meets the operational requirements of precision control equipment such as thermal control instruments and pneumatic valves after being processed by the combined dryer. It also allows the conveying and maintenance air transmitted through the second air supply header to reach a general quality state that meets the operational requirements of auxiliary equipment such as ash removal conveying and maintenance purging after being processed by the compression heat regeneration adsorption dryer. By using the high-temperature exhaust heat of the centrifugal air compressor to directly heat the regenerated desiccant in the compression heat regeneration adsorption dryer, the desiccant regeneration process can be completed without additional electricity or compressed air consumption, significantly reducing the regeneration energy consumption and air consumption in the post-processing stages of conveying and maintenance air. This allows for the matching of different types of drying equipment to different air qualities, based on the implementation of graded air supply. This ensures that the high-quality requirements of instrument compressed air meet the air safety requirements of precision control equipment, while also utilizing the waste heat from the centrifugal air compressor's own exhaust to achieve low-energy regeneration of the conveyed air, further reducing the overall energy consumption of the compressed air system.

[0034] In some feasible implementations, the air compression system of a thermal power plant further includes: a gas transmission header inlet regulating device, used to regulate the inlet volume of the first gas transmission header and the second gas transmission header according to the gas pressure in the first gas transmission header, so as to regulate the inlet volume of the corresponding gas-consuming equipment.

[0035] For example, the gas inlet regulating device for the gas transmission main can be an electrically controlled door.

[0036] The air compression system for thermal power plants provided in this application embodiment regulates the air intake of the first and second gas transmission headers based on the gas pressure in the first header, thereby adjusting the air intake of corresponding air-consuming equipment. This allows the system to promptly reduce the air intake of the second header and correspondingly increase the air intake of the first header when the gas pressure in the first header decreases due to increased demand for instrument compressed air or insufficient supply. This prioritizes the supply of instrument compressed air and prevents precision control equipment such as thermal control instruments and pneumatic valves from malfunctioning or failing to operate due to insufficient air pressure. By linking pressure regulation with air supply distribution, dynamic optimization of air distribution among different gas-consuming headers can be achieved without increasing the number of operating air compressors in emergency situations such as insufficient total air supply or load fluctuations. The air intake of the second header is gradually restored after the gas pressure in the first header returns to normal. It can prioritize the safety of air supply to critical air-consuming equipment without increasing the operating power of the equipment, and improve the operational reliability and adjustment flexibility of the compressed air system under abnormal operating conditions and load fluctuations.

[0037] The core advantage of this invention lies in its significant energy-saving effect. The energy efficiency ratio of the centrifugal air compressor is approximately 5.5, which is about 8.3% lower than that of the screw air compressor (6.0). Taking the recommended scheme of this invention as an example, the newly added 4 centrifugal air compressors (Q=140m³ / min, P=0.75MPa) in this phase are compared with the newly added 8 screw air compressors (Q=69.2Nm³ / min, P=0.75MPa). The operating power of the 4 units is 4740.8kW and 4982.4kW respectively. Calculated based on 5000 hours of operation per year and an electricity cost of 0.4 yuan / kWh, the second phase alone can save approximately 483,200 yuan in electricity costs annually. Compared with an all-screw air compressor, the technical solution provided in this application can significantly save operating costs compared to using screw air compressors exclusively. The total economic cost is shown in Table 1 below: Table 1. Economic Comparison of Two Options (Unit: 10,000 RMB)

[0038] Because centrifugal air compressors are oil-free and have no wearing parts, their operation and maintenance workload is far less than that of screw air compressors. This invention, by using a centrifugal air compressor as the primary air supply device, significantly reduces the operating time and number of screw air compressors in operation, thereby substantially lowering equipment maintenance costs. It is estimated that the annual equipment maintenance cost for the centrifugal + screw combination scheme is 390,000 yuan, while the annual equipment maintenance cost for the all-screw scheme is 640,000 yuan, resulting in a saving of 250,000 yuan per year. Furthermore, the reduction in the number of units also lowers the procurement and storage costs of spare parts.

[0039] Taking the second phase expansion project of a power plant (2×1000MW) as an example, this phase of the project plans to construct two 1000MW ultra-supercritical once-through boilers, with the boiler design coal type being Shenhun 5000. The plant's compressed air demand includes multiple specialties such as ash removal, thermal power, thermal control, desulfurization, and water treatment, with a total compressed air consumption of approximately 343.6 Nm³ / min (intermittent use is calculated at 60%). Considering a 10% margin and dryer losses, the total air volume required by the air compressors is 395.14 Nm³ / min. The first phase of the power plant, with its two 1000MW units already in operation, has a total of eight air compressors in its air supply center, with a compressor output of 69.2 Nm³ / min and a pressure of P=0.75 MPa, configured as six operational and two standby. The first phase project uses screw-type air compressors throughout, resulting in a large workload for equipment maintenance and relatively high energy consumption. The second phase of the project includes a new air supply center, which will unify the design of the instrumentation, maintenance, and ash removal compressed air systems of both the first and current phases. This phase adds four 140 Nm³ / min centrifugal air compressors and four 150 Nm³ / min air post-processing units. Two centrifugal air compressors will supply instrumentation air, and two will supply transport and miscellaneous air, connected to the instrumentation compressed air main pipeline and transport air main pipeline of the first phase, respectively. This phase also adds three 60 m³ instrumentation air storage tanks and two 60 m³ ash removal and maintenance air storage tanks. The air supply center is located at zero meters above the blower frame and includes maintenance areas and lifting equipment for convenient daily system maintenance. See Table 2 below for specific configurations. Table 2. Main Equipment Configuration for Phase II Project

[0040] During normal operation, the eight screw air compressors in Phase I (3 in operation and 5 on standby) and the four centrifugal air compressors in Phase II (4 continuously operating) operate in combination, with priority given to adjusting the air pressure through loading and unloading of the screw air compressors. Among them, two centrifugal air compressors and two screw air compressors are used for air supply and maintenance in Phases I and II, while the other two centrifugal air compressors and one screw air compressor are used for instrumentation in Phases I and II.

[0041] Centrifugal air compressors are not suitable for frequent start-stop operations due to their high speed; once started, it is generally not recommended to stop them. Therefore, one or two screw air compressors are used to regulate the air supply system. When the air consumption fluctuates within the adjustable range (75%–100%) of the centrifugal air compressor, fine adjustments are made only through the centrifugal air compressor's inlet guide vanes. When the air consumption exceeds this range, the screw air compressor is started to regulate the flow, avoiding venting from the centrifugal air compressor and minimizing energy waste.

[0042] As an alternative to this invention, the all-screw air compressor solution involves constructing a separate air supply center in the second phase of the project, using a micro-oil screw compressor system. The specific configuration is as follows: eight micro-oil screw air compressors (each with a power of 400kW and a capacity of 69.2 Nm³ / min and P=0.75MPa), six operating continuously and two on standby; the after-treatment system uses eight combined dryers with a capacity of 70 Nm³ / min.

[0043] The advantages of this scheme are its flexible adjustment, uniform type of all air compressor equipment, good mutual backup conditions, and consistent spare parts specifications, facilitating maintenance and repair. Furthermore, this scheme uses the same configuration for the dry ash conveying system and the air compressors and post-treatment systems for instrument compressed air, making the gas supply connections for the entire plant flexible and convenient, with a lower initial investment (7.53 million yuan). Detailed comparative data is shown in Table 3 below: Table 3. Comprehensive Comparison of the Two Schemes

[0044] Based on the above technical and economic comparisons, the centrifugal + screw combination scheme of the present invention has the following technical advantages: First, the centrifugal air compressor has a lower energy consumption ratio and a lower operating electrical load than the all-screw scheme; second, the compression heat regeneration adsorption dryer fully utilizes the exhaust heat of the centrifugal air compressor, eliminating the need for additional heating energy; third, the number of devices is smaller, resulting in less maintenance workload; fourth, the annual cost is 400,000 yuan lower, leading to significant long-term economic benefits. Although the initial investment is slightly higher at 1.27 million yuan, considering the reduction in energy consumption and maintenance costs, the present invention is the optimal solution.

[0045] Figure 3 This is a schematic flowchart illustrating a control method for an air compression system in a thermal power plant, provided as an embodiment of this application. Figure 3 As shown, in a second aspect of this application, a control method for an air compression system in a thermal power plant is provided, applied to any of the air compression systems in the first aspect described above. The control method for the air compression system in a thermal power plant includes: Step S110: After the completion of both the first and second construction cycles, configure multiple screw air compressors to switch loading and unloading operation states according to instructions, and configure multiple centrifugal air compressors to operate continuously.

[0046] Step S120: The gas output from the centrifugal air compressor and the screw air compressor through the gas transmission header is supplied to the gas-using equipment.

[0047] Step S130: The controller outputs adjustment commands to the screw air compressor based on the gas pressure output by the centrifugal air compressor, so as to control the screw air compressor to adjust the loading and unloading operation status according to the adjustment commands; wherein, the multiple centrifugal air compressors and the multiple screw air compressors are obtained through phased construction, and the multiple screw air compressors are completed after the completion of the first construction cycle, and the multiple centrifugal air compressors are completed after the completion of the second construction cycle. The completion time of the first construction cycle is earlier than the completion time of the second construction cycle.

[0048] The control method for the air compression system of a thermal power plant provided in this application involves configuring multiple screw air compressors to switch loading and unloading operation states according to instructions after the completion of both the first and second construction cycles, configuring multiple centrifugal air compressors to operate continuously, and supplying the gas output from the centrifugal and screw air compressors to the gas-consuming equipment through the gas transmission header. This allows the centrifugal air compressors to continuously and efficiently supply gas to the base load during the stable operation period, while the screw air compressors can switch operation states according to actual working conditions to achieve flexible adjustment of the gas volume. The construction of multiple centrifugal air compressors and multiple screw air compressors is carried out in phases. The screw air compressors are completed in the first phase, and the centrifugal air compressors are completed in the second phase. The completion time of the first phase is earlier than that of the second phase. This allows the power plant to initially utilize the flexible and adaptable screw air compressors, which can withstand fluctuating loads, to ensure compressed air supply for unit commissioning and trial operation. Once the power plant enters a stable operating period, high-efficiency centrifugal air compressors can be introduced as the main air supply equipment, thus achieving a smooth transition and system upgrade from the construction phase to the operation phase. Furthermore, the controller outputs adjustment commands to the screw air compressors based on the gas pressure output from the centrifugal air compressors. This allows the screw air compressors to adjust their loading and unloading status according to the adjustment commands. When the centrifugal air compressors experience insufficient or excessive output due to fluctuations in air load, the screw air compressors can provide real-time compensation and adjustment through loading or unloading. This allows for the balance between ensuring reliable gas supply during the construction phase and optimizing energy efficiency during the operation phase throughout the entire lifecycle of a thermal power plant. Under the premise of ensuring gas supply safety, it can significantly reduce the long-term operating energy consumption and maintenance costs of the compressed air system, while simultaneously meeting the dual requirements of energy conservation, environmental protection, and high-quality air compression.

[0049] In some feasible implementations, the control method for the air compression system of a thermal power plant also includes: during the period when the first construction cycle has been completed but the second construction cycle has not been completed, all screw air compressors built during the first construction cycle are used to supply air to air-consuming equipment; after the second construction cycle is completed, some screw air compressors are suspended from operation.

[0050] The control method for the air compression system of a thermal power plant provided in this application utilizes all screw air compressors built during the first construction cycle (when the first construction cycle is completed but the second construction cycle is not yet completed) to supply air to air-consuming equipment. This allows the thermal power plant to flexibly adjust the air supply by loading and unloading all screw air compressors during the initial construction phase, when the air load is unstable and centrifugal air compressors are not yet operational. This ensures a sufficient supply of compressed air during unit commissioning and trial operation, meeting the high-quality air demand of the thermal power plant during the initial construction phase. Furthermore, by suspending the operation of some screw air compressors after the completion of the second construction cycle, newly added high-efficiency centrifugal air compressors can assume the base load air supply, while some screw air compressors that were originally running continuously can be put into standby mode. This reduces the number of operating screw air compressors, thereby reducing equipment maintenance workload and spare parts consumption, and improving the operating economy of the compressed air system while ensuring the reliability of the air supply. It can enable the orderly connection and system upgrade of the air compression system of thermal power plants from the construction period to the operation period, and avoid the energy waste and increased maintenance costs caused by the existing screw air compressors still operating at full load after the centrifugal compressors are put into operation.

[0051] In some feasible implementations, the control method for the air compression system of a thermal power plant further includes: determining the target air delivery volume of the centrifugal air compressor based on the actual guide vane opening of the centrifugal air compressor; determining the aging degradation score of each centrifugal air compressor based on the target air delivery volume and the actual air delivery volume of the centrifugal air compressor; and starting up some of the suspended screw air compressors and generating alarm information when the aging degradation score is lower than the preset score threshold.

[0052] It should be noted that centrifugal air compressors, due to their high speed, are not suitable for frequent start-stop operations; generally, once started, they should not be stopped. Screw air compressors, however, can be shut down for performance recovery or maintenance. After the second construction phase, centrifugal air compressors will operate continuously for extended periods. This prolonged continuous operation inevitably leads to machine aging and performance degradation. Once the centrifugal air compressor ages and deteriorates, its actual air supply will gradually decrease under the same inlet guide vane opening. If the controller consistently determines whether the centrifugal air compressor is operating at full load based on its actual guide vane opening and adjusts the screw air compressor based on the difference between the actual and target air supply, the controller will misjudge the situation, resulting in continuous and frequent loading of the screw compressor. This negatively impacts the energy-saving effect of the power plant's air compression system, increases the risk of centrifugal air compressor failure, and further increases the operational risk of the power plant's air compression system.

[0053] The control method for the air compression system of a thermal power plant provided in this application determines the target air delivery volume of the centrifugal air compressor based on the actual guide vane opening of the centrifugal air compressor, thus establishing a benchmark for the air supply volume that the centrifugal air compressor should achieve under the current guide vane opening. Since the centrifugal air compressor will operate continuously for a long period after commissioning, this continuous operation will inevitably lead to machine aging, degradation, and performance deterioration. Under the same inlet guide vane opening, the actual air supply volume of the centrifugal air compressor will gradually decrease. If the controller always determines whether the centrifugal air compressor is under full load adjustment based on the actual guide vane opening and adjusts the screw air compressor based on the difference between the actual air delivery volume and the target air delivery volume, it will lead to misjudgment by the controller. By comparing the target air delivery volume with the actual air delivery volume and quantifying it as an aging degradation score, the controller can proactively identify the degree of performance degradation of the centrifugal air compressor caused by factors such as impeller wear, cooler scaling, and increased pressure loss of the inlet filter, avoiding the energy-saving effect reduction caused by the controller continuously and frequently loading the screw compressor due to failure to recognize centrifugal aging. Furthermore, by activating and triggering alarms on some suspended screw air compressors when the aging degradation score falls below a preset threshold, the system can automatically wake up standby screw air compressors to supplement air supply and maintain stable mains pressure when the performance of a centrifugal air compressor deteriorates to the point where it cannot meet current air demand. Simultaneously, it notifies operation and maintenance personnel to inspect and repair the aging centrifugal air compressors to restore their air supply capacity in a timely manner. This system can automatically identify and compensate for insufficient air supply after long-term continuous operation of centrifugal air compressors leads to performance degradation. While ensuring reliable air supply, it avoids the risk of frequent screw compressor loading and centrifugal compressor failure due to controller misjudgment, thus improving the long-term operational stability and energy-saving effect of the compressed air system.

[0054] Figure 4 This is a schematic structural diagram of a control device for an air compression system in a thermal power plant, provided as an embodiment of this application. Figure 4As shown, in a third aspect of this application, a control device for a thermal power plant air compression system is provided, which is used to execute a control method for a thermal power plant air compression system as described in any of the second aspects above. The control device for the thermal power plant air compression system includes: an operation configuration module 10, a gas transmission module 20, and an operation control module 30. The operation configuration module 10 is used to configure multiple screw air compressors to switch loading and unloading operation states according to instructions and to configure multiple centrifugal air compressors to operate continuously after the completion of the first and second construction cycles. The gas transmission module 20 is used to supply the gas output from the centrifugal air compressors and screw air compressors to the gas-consuming equipment through the gas transmission header. The operation control module 30 is used to output adjustment instructions for the screw air compressors according to the gas pressure output by the centrifugal air compressors, so as to control the screw air compressors to adjust the loading and unloading operation states according to the adjustment instructions. The multiple centrifugal air compressors and multiple screw air compressors are obtained through phased construction, and the multiple screw air compressors are completed after the completion of the first construction cycle and the multiple centrifugal air compressors are completed after the completion of the second construction cycle. The completion time of the first construction cycle is earlier than the completion time of the second construction cycle.

[0055] Figure 5 This is a schematic structural diagram of a storage medium provided in an embodiment of this application. Figure 5 As shown, in a third aspect of the present application, a storage medium is provided, which stores a computer program 00. When the computer program 00 is executed by a processor, it implements the control method of the air compression system of a thermal power plant as described in any of the second aspects above.

[0056] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in a variety of forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), RAMbus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0057] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is used as an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above.

[0058] The specific implementation process of the above method steps can be found in any of the above embodiments of the processing method for unstructured data based on the financial industry, and will not be repeated here.

[0059] The above embodiments are merely exemplary embodiments of this application and are not intended to limit this application. The scope of protection of this application is defined by the claims. Those skilled in the art can make various modifications or equivalent substitutions to this application within its substance and scope of protection, and such modifications or equivalent substitutions should also be considered to fall within the scope of protection of this application.

[0060] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

[0061] Although preferred embodiments have been described in this specification, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this specification.

[0062] Obviously, those skilled in the art can make various modifications and variations to this specification without departing from its spirit and scope. Therefore, if such modifications and variations fall within the scope of the claims and their equivalents, this specification is also intended to include such modifications and variations.

Claims

1. An air compression system for a thermal power plant, characterized in that, include: Multiple screw air compressors, wherein the screw air compressors are configured to switch loading and unloading operation states according to instructions; Multiple centrifugal air compressors, which are configured to operate continuously; A main gas pipeline is used to supply the gas output from the centrifugal air compressor and the screw air compressor to the gas-consuming equipment; The controller is used to output adjustment commands for the screw air compressor based on the gas pressure output by the centrifugal air compressor, so as to control the screw air compressor to adjust the loading and unloading operation status according to the adjustment commands; The centrifugal air compressors and screw air compressors were constructed in phases. The screw air compressors were completed after the first construction phase, and the centrifugal air compressors were completed after the second construction phase. The completion time of the first construction phase was earlier than the completion time of the second construction phase.

2. The air compression system for thermal power plants according to claim 1, characterized in that, During the period between the completion of the first construction cycle and the completion of the second construction cycle, all screw air compressors built during the first construction cycle are used to supply air to the air-consuming equipment. After the second construction cycle is completed, the operation of some of the screw air compressors will be suspended.

3. The air compression system for thermal power plants according to claim 1, characterized in that, The gas transmission header includes a first gas transmission header and a second gas transmission header. The first gas transmission header is used to transmit a portion of the gas output from the centrifugal air compressor and the screw air compressor to the corresponding gas-consuming equipment. The second gas transmission header is used to transmit another portion of the gas output from the centrifugal air compressor and the screw air compressor to the corresponding gas-consuming equipment. The first gas supply main pipe is used to transmit compressed air for instruments, and the second gas supply main pipe is used to transmit gas for delivery and maintenance.

4. The air compression system for thermal power plants according to claim 3, characterized in that, Also includes: A combined dryer is installed between the first gas transmission header and the corresponding gas-using equipment; A compression heat regeneration adsorption dryer is installed between the second gas supply header and the corresponding gas-using equipment.

5. The air compression system for thermal power plants according to claim 3, characterized in that, Also includes: The gas supply main pipe air intake regulating device is used to adjust the air intake volume of the first gas supply main pipe and the second gas supply main pipe according to the gas pressure in the first gas supply main pipe, so as to regulate the air intake volume of the corresponding gas-using equipment.

6. A control method for an air compression system in a thermal power plant, characterized in that, The control method for the air compression system of a thermal power plant, as described in any one of claims 1 to 5, comprises: After the completion of the first and second construction cycles, multiple screw air compressors will be configured to switch loading and unloading operation modes according to instructions, and multiple centrifugal air compressors will be configured to operate continuously. The gas output from the centrifugal air compressor and the screw air compressor is supplied to the gas-consuming equipment through the gas transmission header; The controller outputs adjustment commands to the screw air compressor based on the gas pressure output by the centrifugal air compressor, thereby controlling the screw air compressor to adjust its loading and unloading operation status according to the adjustment commands. The centrifugal air compressors and screw air compressors were constructed in phases, with the screw air compressors completed after the first construction cycle and the centrifugal air compressors completed after the second construction cycle. The completion time of the first construction cycle was earlier than the completion time of the second construction cycle.

7. The control method for an air compression system in a thermal power plant according to claim 6, characterized in that, Also includes: During the period between the completion of the first construction cycle and the completion of the second construction cycle, all screw air compressors built during the first construction cycle are used to supply air to the air-consuming equipment. After the second construction cycle is completed, the operation of some of the screw air compressors will be suspended.

8. The control method for an air compression system in a thermal power plant according to claim 7, characterized in that, Also includes: The target air delivery rate of the centrifugal air compressor is determined based on the actual guide vane opening of the centrifugal air compressor. Based on the target air delivery volume and the actual air delivery volume of the centrifugal air compressor, determine the aging degradation score of each centrifugal air compressor; If the aging degradation score is lower than a preset score threshold, the portion of the screw air compressor that was previously in operation will be started and an alarm message will be generated.

9. A control device for an air compression system in a thermal power plant, characterized in that, For executing the control method of the air compression system of a thermal power plant as described in any one of claims 6 to 8, the control device of the air compression system of the thermal power plant includes: The operation configuration module is used to configure multiple screw air compressors to switch loading and unloading operation states according to instructions, and to configure multiple centrifugal air compressors to continuous operation state after the completion of the first construction cycle and the second construction cycle. A gas transmission module is used to supply gas output from the centrifugal air compressor and the screw air compressor to the gas-consuming equipment via a gas transmission header. The operation control module is used to output adjustment commands to the screw air compressor based on the gas pressure output by the centrifugal air compressor, so as to control the screw air compressor to adjust the loading and unloading operation status according to the adjustment commands; The centrifugal air compressors and screw air compressors were constructed in phases, with the screw air compressors completed after the first construction cycle and the centrifugal air compressors completed after the second construction cycle. The completion time of the first construction cycle was earlier than the completion time of the second construction cycle.

10. A storage medium, characterized in that, The storage medium stores a computer program, which, when executed by a processor, implements the steps of the control method for the air compression system of a thermal power plant according to any one of claims 6 to 8.

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