Abstract:An abnormal vibration occurred in the drain pipe of the high-pressure heater of a thermal power station,causing severe erosion of the pipe.Particularly at the bends,it affected the safe and stable operation of the unit.By investigating the causes of the abnormal vibration of the drain pipe of the high-pressure heater in this thermal power station,and conducting calculation and analysis using the pipeline stress analysis software CAESAR Ⅱ,the main cause of the abnormal vibration of the pipe is determined,and improvement measures are proposed.It is found that the design defect of the pipe support led to insufficient stiffness,and the pulsation excitation generated by the gas-liquid two-phase flow coupled with the third-order mode frequency of the piping system is the main cause of the vibration.By adjusting the layout of the pipe support and improving the rigidity of the pipe,the third-order mode frequency of the pipe can be increased,effectively solving the vibration problem of the drain pipe.Optimizing the layout of the pipe support can effectively solve the vibration problem,providing a reference for the design of high-pressure heater drain pipes in new power plants.

Abstract:To study the carbon emissions of the external insulation walls of prefabricated residential buildings in cold regions,based on the full life cycle theory,the full life cycle of prefabricated concrete insulation exterior walls is divided into five stages:production,distribution,construction,operation and demolition.A carbon emission calculation model for the full life cycle of prefabricated concrete insulation exterior walls is established,and the carbon emission factor method is used to calculate its full life cycle carbon emissions.The results show that the carbon emissions from the production stage account for 90.28%of the total carbon emissions,while those from other stages together account for 9.72%.The production stage makes a significant contribution to the carbon emissions throughout the entire life cycle.Putting forward suggestions on energy-saving and emission reduction methods in the production stage is conducive to the transformation of the production of prefabricated concrete insulation exterior wall components in cold regions,achieving energy-saving and emission reduction in the construction industry,and contributing to the realization of the'double carbon'goals.

Abstract:To improve the prediction accuracy of the energy storage frequency regulation instructions for wind farms,the global curvature-stability analysis method is adopted to calculate the non-linear degree(curvature scaling factor)S1 of the deviation from the linear trend of the original wind speed sequence and the stability(change suppression index)S2 of the sequence value changes.The update gate parameters of the gated recurrent unit(GRU)are dynamically adjusted using the non-linear degree S1 and stability S2,and the original wind speed sequence is placed in the improved GRU network for prediction,obtaining the final prediction result.The results show that in terms of prediction error,the method proposed in this study reduces the MAE of the GRU network by an average of 83.34%,the SSE by an average of 98.24%,the RMSE by an average of 74.21%,and the MAPE by an average of 86.10%compared to the GRU network.

Abstract:Taking the sintering desulfurization and denitrification project of a certain steel enterprise as the research object,based on the actual operation data of the existing activated carbon process,the energy consumption index and carbon emissions are systematically analyzed,and the energy-saving and carbon reduction potential of the circulating fluidized bed(CFB)desulfurization+selective catalytic reduction(SCR)denitrification process is compared and predicted.The results show that compared with the existing activated carbon desulfurization and denitrification process,the energy consumption index can be decreased by approximately 48.9%,with an annual reduction of 19 320 tons of standard coal in energy consumption and a 43.4%decrease in carbon emissions,resulting in an annual reduction of 122 640 t of carbon emissions.

Abstract:To investigate the energy utilization status of liquefied natural gas(LNG)receiving stations,taking a large domestic LNG receiving station as the research object,a method combining on-site testing and data analysis is adopted to calculate the efficiency and conduct economic evaluations of the low-pressure pumps,high-pressure pumps,BOG compressors and seawater pumps of this receiving station.Specific optimization measures are proposed in terms of equipment maintenance management,intelligent control,operation processes and equipment renovation.The results showed that the low-pressure pump and high-pressure pump units are not economically operated by 57.1%and 33.3%,respectively.The seawater pump unit is not economically operated at all.The BOG compressor operated reasonably.Through measures such as optimizing unit operation,strengthening equipment maintenance,and implementing frequency conversion renovations,annual electricity costs are saved and CO2 emissions are reduced.

Abstract:To address the technical issues such as weak carrying capacity and small downwash flow field existing in current agricultural unmanned aerial vehicle,a coaxial dual-rotor system is introduced to enhance operational efficiency and pesticide application quality.The research focused on the aerodynamic principles of this system,using computational fluid dynamics(CFD)methods to numerically simulate and analyze the downwash flow field of the rotors,and exploring the flow field structure and droplet movement characteristics.The results show that the coaxial dual-rotor design can significantly enhance the downwash airflow,improve the penetration power and uniformity of pesticide spraying,and effectively enhance the carrying capacity.The optimal operating height determined through parameter optimization is 1.5 m.The proposed scheme has the characteristics of high efficiency,precision,and strong adaptability,and can provide technical references for modern agricultural pest control operations.

Abstract:Aiming at the problems of long construction period,high load and unfavorable evaluation of prefabricated buildings in traditional wet floor radiant heating,a cavity-type radiant heating system that combines prefabrication and heating comfort is proposed.By setting up an experimental platform,the thermal performance differences between this system and the traditional wet radiant heating system under different water supply parameters are compared and analyzed.With the aid of numerical simulation,the influence of the temperature field and flow field distribution of the surface layer structure and the size of the cavity module is studied.The results show that the air interlayer of the cavity-type radiant heating system has good thermal insulation performance and can meet the comfort requirements at a lower water supply temperature.The air velocity distribution within the air interlayer presents an'∞'shaped circulation.Appropriately increasing the height and width of the cavity module can effectively improve the floor surface temperature and heat flux density.

Abstract:To address the issues of declining auxiliary equipment efficiency and rising coal consumption for power supply caused by low-load operation of coal-fired power units under the background of deep peak shaving in coal-fired power,and to assist in achieving the'double carbon'goals and the transformation to the new generation of coal-fired power,research on the application of permanent magnetization technology for coal-fired power auxiliary equipment is carried out.Through data calculation,case comparison and technical characteristic analysis,the current energy consumption situation of coal-fired power auxiliary equipment and the limitations of asynchronous motors are sorted out,and the technical advantages of permanent magnet motors are analyzed.Based on actual renovation cases,verify its application effect and analyze the constraints currently faced by the promotion of the technology.The results show that if permanent magnet auxiliary machines are fully applied in the country's coal-fired power plants,it is estimated that 200 million tons of standard coal can be saved annually,and about 50 million tons of carbon dioxide emissions can be reduced.Currently,the promotion of permanent magnet auxiliary machines still faces challenges such as an incomplete industrialization system and insufficient pilot demonstrations.The promotion of permanent magnet auxiliary machines still faces challenges such as an incomplete industrialization system and insufficient pilot demonstrations at present.Research suggests that the permanent magnetization technology for auxiliary equipment is a key path to breaking the problem of excessive coal consumption under low load in coal-fired power and promoting the clean and efficient transformation of the new generation of coal-fired power.It is necessary to accelerate its large-scale application through measures such as industrial innovation and standard improvement.

Abstract:In response to the'double carbon'goals and to optimize the energy structure,exploring the design and equipment selection methods of photovoltaic power stations.By combining theoretical analysis with case studies,discusses the composition and key calculations of photovoltaic power generation systems,and takes the 2.5 MW industrial park power station as the research object for analysis.The results show that through optimized design,an annual power generation of 3.28 million kWh can be achieved,the CO2 emission reduction is 2 600 t,and the payback period of investment is 5.3 a.The research indicates that proper design calculations and equipment selection are crucial means for enhancing power generation efficiency and are of great significance for promoting the green transformation in the industrial sector.

Abstract:The heat exchange performance of the solid heat storage system directly affects the thermal output power of the system and the efficiency of the heat storage and release cycle.Among them,the structure of the heat storage duct is a key factor.For a specific solid heat storage duct structure,the Fluent software is used to simulate and study the heat storage and release characteristics of the heat storage module in the solid electroheat storage device,analyze the influence of the duct structure,and conduct thermal calculations for the matching conditions of the main components of the device.The results show that after 8 h of heating,the average temperature of the heat storage body increased from 300.00 K to 1 008.64 K,the maximum temperature difference in the same cross-section is 2.57 K,and the heat storage capacity of the heat storage module reached 1 482.08 kWh.During the heat release process,the U-shaped duct heat transfer structure enables the air to stay for a longer time.Air with an initial temperature of 300 K passing through the U-shaped heat storage body of the initial temperature of 765 K for heat release can reach an outlet air temperature of up to 577.01 K.The thermal calculations of the system obtained key parameters such as the surface load of the heating wire 11.4 W/m2,the heat exchange area 255.5 m2,and the fan power 7.5 kW.The study shows that the dual-channel structure can significantly improve temperature uniformity and heat exchange efficiency,providing a reference for the design and operation optimization of the solid electroheat storage system.

Abstract:Based on the premixed flame experimental bench,the influence laws of three key parameters,namely the excess air coefficient,flame heat load and heating surface height,on the heat flux density distribution,heat flux distribution and thermal efficiency variation of the quartz plate are studied,and the temperature field on the surface of the quartz plate is collected by using an infrared thermal imager.The results show that when α is 0.5～0.8,the distribution of heat flux density along the radial direction shows a trend of first increasing and then decreasing.At this time,the peak of heat flux density occurs in the corresponding local high-temperature area.When α is between 0.9 and 1.1,the distribution of heat flux density shows a gradually decreasing trend.At this time,the peak of heat flux density occurs in the core high-temperature zone corresponding to the center position.The heat flux through the quartz plate increases with the increase of flame heat load,but the thermal efficiency decreases.When the height of the heating surface H is 15 mm and the flame heat load Qflame is 0.4 kW,the maximum thermal efficiency in the experiment is approximately 60%.

Abstract:To enhance the heating process of steel furnaces and reduce pollutant emissions,a 300 kW flameless pure oxygen burner is selected as the research object.By combining principle design,experimental testing and computational fluid dynamics(CFD)simulation,the system design process of the flameless pure oxygen burner is established.Through experimental testing,its heating characteristics are obtained,and the CFD simulation results are used to further verify the experimental results.The results show that the system can achieve flameless combustion at a furnace temperature range of 700℃to 800℃.The CFD simulation indicates that the temperature uniformity inside the furnace is good,and the numerical analysis is in good agreement with the experimental results.

Abstract:In response to the problems such as increased inter-stage cooling resistance,restricted flow rate and increased unit energy consumption that occurred in the 21 000 m3/h oxygen production unit of Liansteel during the hot season,an energy-saving renovation is implemented,focusing on replacing the core bodies of the first and second stage coolers and optimizing the operation strategies.The results show that after the renovation,the average inlet flow rate of the air compressor increased from 106 273 m3/h to 120 625 m3/h,the average inlet tower flow rate increased from 97 761 m3/h to 109 900 m3/h,the average pressure drop of the first stage cooler decreased from 28.13 kPa to 4.76 kPa,the exhaust pressure increased by 5.14%,and the average oxygen production energy consumption decreased from 0.762 kWh/m3 to 0.719 kWh/m3.The project achieved a monthly comprehensive benefit of approximately 1.63 million yuan,with a static investment recovery period of approximately 0.65 months,demonstrating significant economic benefits.The research verified the efficient energy-saving path based on optimizing inter-stage cooling,and has important promotional effects for the energy-saving renovation and lean operation of similar deep cryogenic air separation units.

Abstract:In the design of the gravity heat pipe heat exchange system for mine intake and return air,due to the fact that the length ratio of the evaporation section to the condensation section is basically the same under various working conditions,it is difficult to meet the performance optimization requirements.Based on the idea of asymmetric segment ratio,a mathematical model of gravity heat pipe return air heat exchange is established,and field tests are conducted on the gravity heat pipe system of a certain coal mine in Shaanxi Province under extremely cold conditions.The results show that the relative errors between the predicted values and the measured values are all less than 6%.The flow rate has a significant impact on the heat transfer performance of the evaporation section and the condensation section.When the ratio of the evaporation/condensation section is optimized to 1.9∶2.6～2.1∶2.4,the best intake air heating effect and single-tube heat exchange capacity can be achieved.

Abstract:Exploring technologies such as smart electricity meters,high-speed acquisition systems,and metering data platforms,and analyzes their applications in precise line loss management,demand-side response guidance,energy efficiency analysis,and carbon accounting support.The research shows that the technology can control the measurement error within 0.2%,achieve minute-level collection of electricity data,provide key data support for identifying energy efficiency potential,optimizing energy allocation,and quantifying carbon reduction benefits,and is of great significance for promoting the green and low-carbon transformation of the power grid.

Abstract:To ensure the accuracy,timeliness and green low-carbon goals of water environment management,focusing on the dike corner section of the Yangtze River Basin,a technical framework integrating intelligent monitoring,dynamic cleaning and integrated source tracing is constructed.By installing high-frequency monitoring equipment to obtain minute-level water quality data,a novel conductivity-pH value-turbidity collaborative diagnostic model is proposed,which effectively identifies sensor failures and solves the problem of high anomaly rate of data in traditional monitoring.By integrating hydrological parameters such as rainfall and flow,a spatiotemporal response matrix is established to analyze the causes and transmission mechanisms of three types of pollution events:Storm runoff,pipe network overflow and industrial emissions.The results show that this integrated system has shortened the pollution warning response time from 4.2 h to 47 min,improved the traceability efficiency,and through intelligent means reduced the frequency of manual inspections and on-site maintenance,indirectly reducing the energy consumption and carbon emissions of management activities,providing a reference for intelligent governance,refined supervision and green operation of the river basin.

Abstract:In view of the problems such as low NO3--N removal rate and poor nitrogen removal efficiency of the existing methods,the optimization of a new low-carbon wastewater treatment process based on the coupling of anaerobic ammonium oxidation and denitrification adopts a spatial segmented coupling strategy,and through the proportional-integral-differential(PID)control algorithm and spatio-temporal gradient aeration control method,the dynamic regulation model integrating multi-dimensional data realizes the multi-parameter coordinated regulation of temperature,carbon-nitrogen ratio(C/N)and dissolved oxygen(DO)concentration.The results show that the NO3--N removal rate of the experimental group within the same time period is 94.3%,enhancing the regulatory effect on the nitrogen transformation process.The DO concentration in the experimental group is within the range of 0.00 mg/L to 0.29 mg/L,and the denitrification efficiency is relatively high,which enhanced the overall efficiency of sewage treatment.

Abstract:Aiming at the problems of high energy consumption and large carbon emissions for building heating in severe cold regions,taking a large office building in Shenyang City as the research object,a water source heat pump system model is constructed based on TRNSYS dynamic simulation technology.Combined with heat recovery and intelligent control strategies,the system energy efficiency is optimized.The research shows that the total heating capacity of the system during the heating season is 426 697.17 kWh,of which 43.25%comes from heat recovery,the peak heating capacity in January reached 157 896.53 kWh,and the energy efficiency ratio(COP)stability is significantly better than that of the traditional system.Through multi-stage temperature regulation,the electricity consumption of the heat pump accounts for 59.07%,and the total electricity consumption is lower than that of similar buildings.Compared with traditional water source heat pump systems,the system has smaller COP fluctuations in the temperature range of-20℃to 5℃,improved low-temperature adaptability,and maintains high energy efficiency during the transition season.

Abstract:Taking a certain wastewater treatment plant in City H as the research object,a carbon emission model is constructed using the emission factor method,and the emissions are calculated based on the operation data from January 2022 to September 2024.The results show that the monthly average carbon emission of the plant is 1 361.97 tCO2,among which the indirect emissions due to electricity consumption are 529.80 tCO2 equivalent per month,and the indirect emissions due to the use of chemicals are 211.70 tCO2 equivalent per month.According to the calculation results,the indirect emissions related to electricity consumption and chemical consumption are the main source of carbon emissions for the wastewater treatment plant in City H.By strengthening operation management,adopting low-energy consumption equipment,and introducing intelligent dosing systems,energy consumption can be effectively reduced.At the same time,renewable energy technologies such as photovoltaic power generation can be supplemented to promote the green and low-carbon operation of the wastewater treatment plant.

Abstract:A short-term photovoltaic power generation prediction model based on adaptive noise complete ensemble empirical mode decomposition-long short-term memory network-sparrow search algorithm(ICEEMDAN-LSTM-SSA)is proposed.Taking a certain photovoltaic power station in Bohu County,Baotou City,Xinjiang as the research object,the influence of different climate conditions on the prediction accuracy is analyzed.The research shows that using the ICEEMDAN decomposition algorithm to preprocess the power generation sequence can effectively improve the prediction accuracy of the LSTM model for photovoltaic power generation,the ICEEMDAN-LSTM-SSA prediction model demonstrates obvious universality under different climate conditions,and the prediction results are more accurate.