Method for reducing energy consumption of nitrogen compressor

Abstract

The invention discloses a method for reducing energy consumption of a nitrogen compressor. The method is suitable for energy-saving transformation of a centrifugal nitrogen compressor. According to the method, annual operation data including flow, pressure, temperature, temperature, humidity and power consumption are collected, and an efficiency distribution curve database is established; on the basis, the modularized efficient three-dimensional impeller and accessories thereof are designed through fluid mechanics software, the adaptive flow ranges from 10000 m < 3 > / h to 20000 m < 3 > / h, and the pressure ranges from 0.5 MPa to 2.0 MPa; replacing the impeller with a special tool, configuring a frequency conversion control system, and adjusting the rotating speed to the optimal efficiency point through a dynamic optimization model; and vibration and noise tests, lubrication and bearing optimization are carried out to ensure that the power is reduced by at least 10%. The embodiment shows that after the SVK16-3S type nitrogen compressor is transformed, the power is reduced to 1400 kW from 1560 kW, the electric charge is saved by about 2 million yuan per year, and the payback period is 1.2 years; through data-driven design and system optimization, remarkable energy conservation is realized, the applicability is wide, the stability is high, and the economic benefit is excellent.

Description

Technical Field

[0001] The present invention belongs to the technical field of compressors and relates to a method for reducing the energy consumption of nitrogen compressors. Background Art

[0002] In the process of global industrialization, the continuous growth of energy consumption has become a common challenge faced by various industries. Especially in high-energy-consuming fields such as chemical industry, metallurgy, and oxygen production, compressors, as core power equipment, often account for more than 30%-50% of the production cost in terms of energy consumption, becoming a key link for enterprises to optimize operational efficiency. Centrifugal nitrogen compressors are widely used in oxygen production systems, nitrogen circulation processes, and gas boosting processes in chemical production due to their characteristics of high flow rate and high pressure. However, many in-service nitrogen compressors have components aging due to their long design years or long-term operation, resulting in significantly higher energy consumption than modern equipment. Taking the SVK16-3S centrifugal compressor in a certain oxygen plant as an example, the operating power of this equipment is as high as 1560 kW, which is 10%-20% higher than that of similar equipment of new models, and the additional cost caused by high energy consumption exceeds one million yuan per year. This phenomenon is not an isolated case in the industrial field, and many old compressors used by enterprises generally have problems of low efficiency and serious energy waste.

[0003] In the prior art, the improvement methods for compressor energy consumption problems mainly include multiple directions such as operating parameter adjustment, replacing high-efficiency components, and introducing control systems. First of all, operating parameter adjustment is a relatively common energy-saving measure. For example, by changing the guide vane opening or manually adjusting the speed, the compressor can approach a higher efficiency under specific working conditions. However, this method is limited by the original aerodynamic characteristics of the equipment, and the efficiency improvement range is usually only between 3%-5%, and it is difficult to maintain a stable effect under variable working conditions (such as seasonal temperature changes or production load fluctuations). Secondly, replacing high-efficiency components (such as three-dimensional impellers) is considered an effective way to improve the performance of compressors. The three-dimensional impeller can significantly improve the aerodynamic efficiency by optimizing the air flow path. Some cases show that the energy consumption can be reduced by up to 8%-10%. However, most existing three-dimensional impellers are of standardized design, which is difficult to accurately match nitrogen compressors of specific models or working conditions, and the replacement cost is high. For example, purchasing a set of high-efficiency impellers and their accessories may cost hundreds of thousands of yuan, and if the whole machine needs to be updated, the cost will be as high as several million yuan. In addition, compatibility problems between new components and old systems (such as insufficient installation accuracy or increased vibration) may also lead to the transformation effect not meeting expectations.

[0004] On the other hand, variable frequency drive (VFD) technology has been widely used in the field of compressor energy conservation in recent years. By adjusting the motor speed to match the actual load demand, VFD can effectively reduce energy consumption, especially under low-load conditions. Industrial practice shows that the energy consumption of some compressors equipped with frequency converters can be reduced by 5%-15%. However, existing VFD control schemes mostly rely on a single parameter (such as flow rate or pressure) as the adjustment basis, lacking a comprehensive analysis of multi-condition characteristics and environmental factors (such as temperature and humidity changes), resulting in significant fluctuations in energy-saving effects during actual operation. In addition, the installation and maintenance costs of frequency converters themselves are relatively high. If not optimized in coordination with the core components of the equipment (such as impellers), their energy-saving potential is difficult to fully utilize.

[0005] In addition to the above methods, there are also some comprehensive renovation schemes in the market, such as combining parameter adjustment and component replacement, or optimizing the operating state by adding a monitoring system. However, these schemes often lack systematic design. For example, some renovations only replace some aging components without considering the improvement of overall aerodynamic efficiency; some other schemes, although they introduce data collection, have a short collection period (such as several weeks or months), which cannot fully reflect the operating characteristics of the equipment under multi-conditions throughout the year, resulting in a lack of pertinence in optimization measures. Taking the SVK16-3S type nitrogen compressor as an example, its operating conditions change significantly with seasons and production demands, and traditional renovation methods are difficult to balance the energy-saving requirements under high-load and low-load conditions. In addition, the scheme of directly replacing the whole machine can completely solve the energy consumption problem, but it has a long shutdown time (usually several months) and a long investment payback period (3-5 years), posing challenges to the production continuity and economy of enterprises.

[0006] In summary, the existing technologies have problems such as limited efficiency improvement, narrow application range, high cost, or insufficient stability in the energy-saving renovation of nitrogen compressors. For old centrifugal nitrogen compressors, how to significantly reduce energy consumption through economical and efficient technical means while retaining the existing equipment foundation and ensuring that the renovation scheme is suitable for various models and operating conditions has become a technical problem to be solved urgently. The present invention is proposed under this background, aiming to provide a systematic and data-driven energy-saving solution. Summary of the Invention

[0007] In view of this, the purpose of the present invention is to solve the above problems and provide a method for reducing the energy consumption of nitrogen compressors.

[0008] To achieve the above purpose, the present invention provides the following technical solutions:

[0009] A method for reducing the energy consumption of nitrogen compressors, applicable to the energy-saving renovation of centrifugal nitrogen compressors, includes the following steps:

[0010] (1) Collect the annual operation data of the centrifugal nitrogen compressor, including flow rate, pressure, inter-stage temperature, ambient temperature and humidity, and power consumption. Analyze the characteristics under multiple working conditions and establish an operation parameter database containing the efficiency distribution curve.

[0011] (2) Based on the operation parameter database, use fluid mechanics calculation software to design a modular high-efficiency three-dimensional impeller and its accessories. Generate an impeller structure suitable for a flow rate range of 10,000 - 20,000 m 3 / h and a pressure range of 0.5 - 2.0 MPa through an adaptive parameter adjustment algorithm.

[0012] (3) Use special tools to replace the original impeller and its components of the centrifugal nitrogen compressor, install the modular high-efficiency three-dimensional impeller and its accessories, and configure a variable frequency control system. Adjust the speed in real time through a dynamic optimization model based on the efficiency distribution curve to make the compressor operate at the best efficiency point.

[0013] (4) Conduct vibration tests, noise detection and mechanical matching verification on the replaced centrifugal nitrogen compressor. Optimize the lubrication system and bearing system. Ensure that the operating power is reduced by at least 10% through coordinated adjustment, thereby achieving energy conservation and consumption reduction.

[0014] Furthermore, in step (1), the collection period of the annual operation data is 12 months, covering high-load, low-load and seasonal change working conditions. Generate a three-dimensional efficiency distribution curve through data analysis. The curve takes flow rate, pressure and speed as variables and is used to determine the best efficiency point under each working condition.

[0015] Furthermore, the operation parameter database includes a compensation coefficient for the impact of ambient temperature and humidity on energy consumption. The compensation coefficient is calculated through regression analysis and is used to correct the aerodynamic parameters in impeller design.

[0016] Furthermore, in step (2), the adaptive parameter adjustment algorithm dynamically optimizes the blade angle, number of blades and inlet diameter of the impeller according to the efficiency distribution curve in the operation parameter database, and generates at least three modular impeller configurations to adapt to different flow rate and pressure requirements.

[0017] Furthermore, the accessories include an adjustable flow guide cover and a high-temperature resistant sealing ring. The adjustable flow guide cover adjusts the opening degree through a servo motor to reduce air flow loss. The high-temperature resistant sealing ring uses a polytetrafluoroethylene composite material with a temperature resistance range of up to 200 °C.

[0018] Furthermore, in step (3), the special tools include a hydraulic disassembly device and a laser alignment instrument. The accuracy of the laser alignment instrument is not less than 0.01 mm, ensuring that the coaxiality error after impeller installation is less than 0.02 mm.

[0019] Furthermore, the variable-frequency control system includes a power sensor, a flowmeter, and an embedded controller. The dynamic optimization model is based on the efficiency distribution curve, calculates the real-time rotational speed through an iterative algorithm, and adjusts the frequency range to 20 - 60 Hz to keep the operating efficiency above 92%.

[0020] Furthermore, in step (4), an acceleration sensor is used for vibration testing to measure the vibration amplitude during operation, and a sound level meter is used for noise detection to measure the operating noise. It is required that the vibration amplitude does not exceed 0.03 mm / s and the noise does not exceed 80 decibels, and the test data is used for feedback to adjust the rotational speed and lubrication parameters.

[0021] Furthermore, the lubrication system optimization includes using a synthetic lubricating oil with a viscosity grade of ISO VG 46 and configuring a device for keeping the oil temperature constant to maintain the oil temperature at 45 - 55°C; the bearing system optimization includes installing self-lubricating ceramic bearings and controlling the bearing clearance at 0.01 - 0.015 mm through a pre-tightening force regulator.

[0022] Furthermore, the method also includes a verification step. After step (3) is completed, a 72-hour transitional operation is performed, gradually increasing the rotational speed to 80%, 90%, and 100% of the rated value, respectively recording the operating power and efficiency. If the power reduction does not reach 10%, the impeller opening or the parameters of the rotational speed optimization model are adjusted according to the test data until the energy-saving target is met.

[0023] The beneficial effects of the present invention are as follows:

[0024] 1. Significant energy-saving effect

[0025] Through the modular high-efficiency ternary impeller and dynamic rotational speed optimization, the operating power is reduced by at least 10%. Taking the embodiment as an example, 160 kW is saved per hour. Calculated at an electricity price of 0.73 yuan per degree, the annual electricity cost savings are about 1 million yuan. Compared with the traditional parameter adjustment (energy saving of about 5%), the energy-saving amplitude of the present invention is doubled, and the economic benefits are significant.

[0026] 2. Wide applicability

[0027] The modular impeller design combined with the adaptive algorithm can adapt to various nitrogen compressor models with a flow rate of 10,000 - 20,000 m 3 / h and a pressure of 0.5 - 2.0 MPa, covering the mainstream equipment in industries such as chemical engineering and oxygen production. Compared with the existing transformation solutions for a single model, the present invention realizes cross-model application through the support of the parameter database and has higher promotion value.

[0028] 3. Excellent operating stability

[0029] Ensure the mechanical stability of the equipment for long-term operation through vibration tests (amplitude ≤ 0.03 mm / s), noise control (≤ 80 dB), lubrication, and bearing optimization. Compared with the vibration or wear problems that may be caused by simply replacing components, the present invention significantly reduces the operation risk and extends the equipment life through system verification and transitional operation.

[0030] 4. Quick return on investment

[0031] The transformation cost is about 1.2 million yuan, and the payback period is only 1.2 years, far lower than the economic burden of replacing the whole machine (the payback period is about 3 - 5 years). Subsequently, it generates a net income of about 1 million yuan per year, providing an efficient cost control means for the enterprise and enhancing its market competitiveness.

[0032] 5. Environmental and social benefits

[0033] For every 1 kWh of electricity saved, about 0.4 kg of carbon dioxide emissions can be reduced. Calculated based on an annual electricity saving of 1 million kWh, about 400 tons of carbon dioxide can be reduced. In addition, reducing energy consumption alleviates the power supply pressure, promotes the green transformation of industry, and provides technical support for the implementation of energy conservation and emission reduction policies.

[0034] Other advantages, objectives, and features of the present invention will be described to some extent in the subsequent specification, and to some extent, will be obvious to those skilled in the art based on the study of the following text, or can be learned from the practice of the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the following specification. Detailed implementation manners

[0035] The following uses specific specific examples to illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation manners, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0036] A method for reducing the energy consumption of a nitrogen compressor, applicable to the energy-saving transformation of a centrifugal nitrogen compressor, includes the following steps:

[0037] (1) Collect the annual operation data of the centrifugal nitrogen compressor, including flow rate, pressure, inter-stage temperature, ambient temperature and humidity, and power consumption, analyze the multi-condition characteristics, and establish an operation parameter database including an efficiency distribution curve;

[0038] (2) Based on the operation parameter database, use fluid mechanics calculation software to design a modular high-efficiency three-dimensional impeller and its accessories, and generate an adaptive parameter adjustment algorithm to generate a flow rate range of 10,000 - 20,000 m 3 / h, an impeller structure with a pressure range of 0.5 - 2.0 MPa;

[0039] (3) Use special tools to replace the original impeller and its components of the centrifugal nitrogen compressor, install a modular high-efficiency ternary impeller and its accessories, and configure a variable-frequency control system. Adjust the rotational speed in real time through a dynamic optimization model based on the efficiency distribution curve to make the compressor operate at the best efficiency point;

[0040] (4) Conduct vibration tests, noise detection, and mechanical matching verification on the replaced centrifugal nitrogen compressor, optimize the lubrication system and bearing system, and ensure that the operating power is reduced by at least 10% through coordinated adjustment, thereby achieving energy conservation and consumption reduction.

[0041] Among them, in step (1), the acquisition period of the annual operation data is 12 months, covering high-load, low-load, and seasonal change working conditions. Generate a three-dimensional efficiency distribution curve through data analysis. The curve takes flow rate, pressure, and rotational speed as variables and is used to determine the best efficiency point under various working conditions. The operation parameter database includes the compensation coefficient for the influence of environmental temperature and humidity on energy consumption. The compensation coefficient is calculated through regression analysis and is used to correct the aerodynamic parameters in impeller design.

[0042] Among them, in step (2), the adaptive parameter adjustment algorithm dynamically optimizes the blade angle, number of blades, and inlet diameter of the impeller according to the efficiency distribution curve in the operation parameter database, and generates at least three modular impeller configurations to adapt to different flow rate and pressure requirements. The accessories include an adjustable flow deflector and a high-temperature resistant sealing ring. The adjustable flow deflector adjusts the opening degree through a servo motor to reduce air flow loss. The high-temperature resistant sealing ring uses a polytetrafluoroethylene composite material with a temperature resistance range of up to 200 °C.

[0043] Among them, in step (3), the special tools include a hydraulic disassembly device and a laser alignment instrument. The accuracy of the laser alignment instrument is not less than 0.01 mm, ensuring that the coaxiality error after impeller installation is less than 0.02 mm. The variable-frequency control system includes a power sensor, a flow meter, and an embedded controller. The dynamic optimization model is based on the efficiency distribution curve and calculates the real-time rotational speed through an iterative algorithm. The adjustment frequency range is 20 - 60 Hz, keeping the operating efficiency above 92%.

[0044] Among them, in step (4), an acceleration sensor is used for vibration testing to measure the vibration amplitude during operation, and a sound level meter is used for noise detection to measure the operating noise. It is required that the vibration amplitude does not exceed 0.03 mm / s and the noise does not exceed 80 decibels, and the test data is used to feedback and adjust the rotational speed and lubrication parameters. The optimization of the lubrication system includes using synthetic lubricating oil with a viscosity grade of ISO VG 46 and configuring a device for maintaining a constant oil temperature to keep the oil temperature at 45 - 55 °C; the optimization of the bearing system includes installing self-lubricating ceramic bearings and controlling the bearing clearance at 0.01 - 0.015 mm through a pre-tightening force regulator.

[0045] This method also includes a verification step. After step (3) is completed, a 72-hour transitional operation is performed, gradually increasing the rotational speed to 80%, 90%, and 100% of the rated value, and recording the operating power and efficiency respectively. If the power reduction does not reach 10%, the impeller opening or the parameters of the rotational speed optimization model are adjusted according to the test data until the energy-saving target is met.

[0047] Example 1: Energy-saving transformation of the SVK16-3S type nitrogen compressor

[0048] For the SVK16-3S type centrifugal nitrogen compressor in a certain oxygen plant, the original operating power is 1560 kW, the designed flow rate is 15000 m 3 / h, the pressure is 1.2 MPa, the operating life is 18 years, and the energy consumption is about 15% higher than that of similar new equipment. The implementation is as follows according to the method of the present invention:

[0049] 1. Data acquisition and database establishment

[0050] Using a flow meter, a pressure sensor, a thermometer, and a power analyzer, operating data is continuously collected for 12 months, including the flow rate (14000 - 16000 m 3 / h), the pressure (1.1 - 1.3 MPa), the inter-stage temperature (30 - 50 °C), the ambient temperature and humidity (5 - 35 °C, 30 - 80% RH), and the power consumption (1500 - 1600 kW). Analyze the data to generate a three-dimensional efficiency distribution curve, and it is found that the best efficiency point is at a rotational speed of 2800 rpm and a flow rate of 15000 m 3 / h, and the efficiency is about 85%. Calculate the ambient temperature and humidity compensation coefficient to be 0.02 for subsequent design.

[0051] 2. Modular impeller design

[0052] Based on the database, a modular high-efficiency three-dimensional impeller is designed using CFD software. The blade angle is optimized to 32° by an adaptive algorithm, the number of blades is 16, the inlet diameter is 450 mm, and it is adapted to a flow rate of 14000 - 16000 m 3 / h. The accessories include an adjustable flow deflector (opening 0 - 30°) and a polytetrafluoroethylene sealing ring (temperature resistance 200 °C).

[0053] 3. Impeller Replacement and Rotational Speed Optimization

[0054] Use a hydraulic disassembly device to remove the original impeller. Install a new impeller with a laser alignment instrument (accuracy 0.01 mm), and the coaxiality error is 0.015 mm. Configure a variable frequency control system, including a power sensor and a flow meter. The dynamic optimization model adjusts the rotational speed to 2850 rpm according to the efficiency curve, the frequency adjustment range is 40 - 50 Hz, and the efficiency is increased to 93%.

[0055] 4. Matching Verification and System Optimization

[0056] The vibration test (amplitude 0.02 mm / s) and noise detection (78 dB) meet the requirements. The lubrication system uses ISO VG 46 synthetic lubricating oil, and the oil temperature is controlled at 48°C; the bearings are replaced with self-lubricating ceramic bearings with a clearance of 0.012 mm. The operating power is reduced to 1400 kW, a decrease of 10.3%.

[0057] 5. Transition Operation Verification

[0058] For a 72-hour transition operation, the rotational speed is gradually increased to 2240 rpm (80%), 2520 rpm (90%), and 2800 rpm (100%). The power is stable at 1400 kW and the efficiency is 93%. No further adjustment is required.

[0059] Effect: After the transformation, 110 kW is saved per hour, and the annual electricity cost savings is about 700,000 yuan (electricity price 0.73 yuan / kWh). The investment is 1.2 million yuan, and the payback period is 1.2 years.

[0060] Example 2: Energy-saving Transformation of K-200 Type Nitrogen Compressor

[0061] For a K-200 type centrifugal nitrogen compressor in a certain chemical plant, the original operating power is 1200 kW, the designed flow rate is 18000 m 3 / h, the pressure is 0.8 MPa, the operating life is 15 years, and the energy consumption is relatively high. Implement as follows according to the method of the present invention:

[0062] 1. Data Acquisition and Database Establishment

[0063] Use sensors to collect 12 months of data, including flow rate (17000 - 19000 m 3 / h), pressure (0.7 - 0.9 MPa), inter-stage temperature (25 - 45°C), ambient temperature and humidity (10 - 40°C, 20 - 90% RH), and power consumption (1150 - 1250 kW). Generate an efficiency distribution curve. The best efficiency point is at a rotational speed of 2600 rpm and a flow rate of 18000 m 3 / h, and the efficiency is about 82%. The temperature and humidity compensation coefficient is 0.015.

[0064] 2. Modular impeller design

[0065] Based on the database, a three - dimensional impeller is designed using CFD software, with a blade angle of 35°, 18 blades, an inlet diameter of 480 mm, and a flow rate adaptation range of 17000 - 19000 m 3 / h. The accessories include an adjustable fairing (opening degree 0 - 25°) and a high - temperature resistant sealing ring.

[0066] 3. Impeller replacement and rotational speed optimization

[0067] The original impeller is removed by a hydraulic disassembly device, and a new impeller is installed by a laser alignment instrument with a coaxiality error of 0.018 mm. A variable - frequency control system is installed, and the rotational speed is dynamically optimized to 2650 rpm through a dynamic optimization model, with a frequency range of 35 - 45 Hz and an efficiency of 92.5%.

[0068] 4. Matching verification and system optimization

[0069] The vibration test (amplitude 0.025 mm / s) and noise detection (79 dB) meet the standards. The lubrication system uses ISO VG 46 lubricating oil with an oil temperature of 50°C; the bearings are ceramic bearings with a clearance of 0.013 mm. The operating power is reduced to 1050 kW, a reduction of 12.5%.

[0070] 5. Transition operation verification

[0071] During the 72 - hour transition operation, the rotational speed is gradually increased to 2080 rpm (80%), 2340 rpm (90%), and 2600 rpm (100%). The power is stable at 1050 kW, and the efficiency is 92.5%, without the need for adjustment.

[0072] Effect: After the transformation, 150 kW is saved per hour, and the annual electricity cost savings are approximately 950,000 yuan (electricity price 0.73 yuan / kWh). The investment is 1.1 million yuan, and the payback period is 1.16 years.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the purpose and scope of the present technical solution, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A method for reducing energy consumption of a nitrogen compressor, applicable to energy-saving transformation of a centrifugal nitrogen compressor, characterized in that: The following steps are involved: (1) Collect the annual operating data of centrifugal nitrogen compressors, including flow, pressure, interstage temperature, ambient temperature and humidity, and power consumption, analyze the characteristics of multiple operating conditions, and establish an operating parameter database including efficiency distribution curves; (2) Based on the operating parameter database, the modular high-efficiency three-dimensional impeller and its accessories are designed using fluid mechanics calculation software, and the adaptive parameter adjustment algorithm is used to generate an adaptive flow range of 10,000-20,000m 3 / h, impeller structure with pressure range of 0.5-2.0MPa; (3) Use special tools to replace the original impeller and its parts of the centrifugal nitrogen compressor, install a modular high-efficiency three-dimensional impeller and its accessories, and configure a variable frequency control system to adjust the speed in real time through a dynamic optimization model based on the efficiency distribution curve, so that the compressor operates at the optimal efficiency point; (4) Conduct vibration tests, noise detection and mechanical matching verification on the replaced centrifugal nitrogen compressor, optimize the lubrication system and bearing system, and ensure that the operating power is reduced by at least 10% through coordinated adjustment, thereby achieving energy saving and consumption reduction.

2. The method for reducing energy consumption of a nitrogen compressor according to claim 1, characterized in that: In step (1), the collection period of the annual operating data is 12 months, covering high load, low load and seasonal change conditions. A three-dimensional efficiency distribution curve is generated through data analysis. The curve uses flow, pressure and speed as variables to determine the optimal efficiency point under each condition.

3. The method for reducing energy consumption of a nitrogen compressor according to claim 1 or 2, characterized in that: The operating parameter database includes compensation coefficients for the effects of ambient temperature and humidity on energy consumption. The compensation coefficients are calculated through regression analysis and are used to correct aerodynamic parameters in impeller design.

4. The method for reducing energy consumption of a nitrogen compressor according to claim 1, characterized in that: In step (2), the adaptive parameter adjustment algorithm dynamically optimizes the blade angle, number of blades and inlet diameter of the impeller according to the efficiency distribution curve in the operating parameter database, and generates at least three modular impeller configurations to adapt to different flow and pressure requirements.

5. The method for reducing energy consumption of a nitrogen compressor according to claim 1 or 4, characterized in that: Accessories include an adjustable air deflector and a high-temperature resistant sealing ring. The adjustable air deflector can adjust its opening through a servo motor to reduce airflow loss. The high-temperature resistant sealing ring is made of polytetrafluoroethylene composite material with a temperature range of up to 200°C.

6. The method for reducing energy consumption of a nitrogen compressor according to claim 1, characterized in that: In step (3), the special tools include a hydraulic disassembly device and a laser centering instrument. The accuracy of the laser centering instrument is not less than 0.01 mm, ensuring that the coaxiality error of the impeller after installation is less than 0.02 mm.

7. The method for reducing energy consumption of a nitrogen compressor according to claim 1 or 6, characterized in that: The frequency conversion control system includes a power sensor, a flow meter and an embedded controller. The dynamic optimization model is based on the efficiency distribution curve. The real-time speed is calculated through an iterative algorithm, and the frequency range is adjusted to 20-60Hz to keep the operating efficiency above 92%.

8. The method for reducing energy consumption of a nitrogen compressor according to claim 1, characterized in that: In step (4), the vibration test uses an acceleration sensor to measure the vibration amplitude during operation, and the noise detection uses a sound level meter to measure the operating noise. The vibration amplitude is required to be no more than 0.03 mm / s and the noise is required to be no more than 80 decibels. The test data is used for feedback to adjust the speed and lubrication parameters.

9. The method for reducing energy consumption of a nitrogen compressor according to claim 1 or 8, characterized in that: The optimization of the lubrication system includes the use of synthetic lubricant with a viscosity grade of ISO VG 46 and the configuration of an oil temperature constant device to maintain the oil temperature at 45-55°C; the optimization of the bearing system includes the installation of self-lubricating ceramic bearings and the control of the bearing clearance at 0.01-0.015mm through the preload adjuster.

10. The method for reducing energy consumption of a nitrogen compressor according to claim 1, characterized in that: The method also includes a verification step. After step (3) is completed, a 72-hour transition operation is performed, and the speed is gradually increased to 80%, 90% and 100% of the rated value. The operating power and efficiency are recorded respectively. If the power reduction does not reach 10%, the impeller opening or speed optimization model parameters are adjusted according to the test data until the energy saving target is met.