Abstract:As a core facility in the information industry,data centers have increasingly prominent issues of energy consumption and heat dissipation as their scale expands.In view of the problems such as low energy utilization rate and serious carbon emissions existing in the data centers of the high-tech zone,based on the low-grade waste heat recovery,district heating and carbon emission model generated by the data centers,an analysis scheme for the utilization of waste heat in data centers is proposed.Taking a certain data center in the high-tech zone as the research object,the potential,economic benefits and social benefits of waste heat utilization are analyzed.The results show that through specific data calculations,it is verified that the utilization of waste heat in data centers has a good energy-saving effect and economic efficiency.

Abstract:Aiming at the problems of blockage,high air leakage rate,and high exhaust temperature rise in the rotary air preheater of a 600 MW supercritical coal-fired unit,a coupling optimization technology scheme for anti blockage and leakage control based on centralized heating of hot fluid is proposed.The scheme achieves comprehensive optimization of the operating parameters of the air preamplifier through the coordinated application of air volume slitting anti-ash clogging technology and flexible contact sealing technology.The results show that after the transformation,the pressure difference on the flue gas side of the air preheater has dropped from 2.2 kPa to below 1.2 kPa,and the air leakage rate has decreased from 8%to 9%to below 4.5%,providing a solution for the comprehensive management of air preheaters in coal-fired units.

Abstract:Relying on the data from the Guangzhou energy management and auxiliary decision-making platform,a model of energy-saving and carbon reduction synergy is constructed,and a sectoral and regional decoupling analysis is conducted on 459 key energy-consuming units(from 2019 to 2023).The results show that the growth rate of the total industrial energy consumption in the city is significantly lower than that of the city's carbon emissions,and the energy consumption per unit of output value in the city shows a year-on-year downward trend.The industrial and transportation sectors are mostly in an unsatisfactory state,while Baiyun,Panyu and Huadu districts have shown a coordinated decoupling trend of economic growth and the decline in energy and carbon emissions from 2022 to 2023.The suggestions on digital management and differentiated policies proposed in the research are of great significance for promoting collaborative governance and achieving the'double carbon'goals.

Abstract:To enhance the utilization efficiency of renewable energy in distributed energy supply systems,thermodynamic analysis is conducted on the solar-biomass gas-micro gas turbine cooling,heating and power system.Mathematical models for heat collection,phase change heat storage,gasification,power generation and dual-effect parallel absorption refrigeration are constructed to study the influences of material types,air-fuel ratio,solar refrigeration distribution and solution split ratio.The results show that the power generation efficiency corresponding to the gasification of wood is greater than 20%,while that corresponding to the gasification of animal fertilizer is only 10%.Increasing the fuel flow rate can reduce the air-fuel ratio,thereby enhancing the output of cold,heat and electricity.The system's electrical efficiency and overall efficiency will also be slightly improved.The higher the proportion of solar energy used for cooling,the higher the overall efficiency of the system.Reducing the split ratio of the dual-effect parallel absorption refrigeration cycle can enhance the performance coefficient of the refrigeration unit,thereby improving the overall efficiency.The micro gas turbine combined heat and power system(CCHP)that utilizes solar thermal energy and biomass gasification can achieve an electrical efficiency of up to 23%and a total efficiency of up to 85%.

Abstract:Large rotating machinery equipment widely adopts tilting-pad journal bearings(TPJBs).However,under high load and long-term operation,the oil film thickness of TPJBs decreases,affecting the efficiency of the unit.Rapidly adjusting the preload of TPJBs is an effective way to change the thickness of the oil film thickness.A lubrication model of variable preload TPJBs is constructed.Taking the pad-6 TPJBs used in 1 000 MW units as the research object,the influence laws of different preloads of tilting-pad on the load capacity performance(such as load,pressure distribution,flow rate,minimum oil film thickness,etc.)and dynamic characteristic coefficients are analyzed.The results show that when the preload factors of pad-1 and pad-4 are adjusted,the pressure distribution characteristics of the symmetrical pads of the top pads(pad-2 and pad-6)and the symmetrical pads of the bottom pads(pad-3 and pad-5)are similar.With the increase of the preload factors,the oil flow rate of the TPJBs gradually increases.Compared with adjusting the preload factors of pad-1 and pad-4,adjusting the preload factors of pad-2 and pad-6,pad-3 and pad-5,and pad-3 and pad-6 increased the minimum oil film thickness by approximately 25.9%,7.4%,and 10.3%,respectively.This research can provide a reference for the design of high-performance TPJBs and energy-saving in terms of loss.

Abstract:Aiming at the problem of high energy consumption proportion of the cooling system in traditional data centers,taking the cooling system of a certain financial data center as the research object,energy-saving optimization is carried out on the cold source system,the air conditioning system of the computer room,the natural cooling mode and the air flow organization of the computer room by system and stage.The results show that after optimization,the average annual power utilization efficiency(PUE)dropped from 3.46 to 1.38,the energy consumption proportion of the cold source system decreased by 22.75%,the energy consumption of precision air conditioners decreased by 65%,and the natural cooling duration is extended by 33 d.The energy-saving path can decrease operating costs,enhance system reliability,and provide a reference for energy efficiency optimization and green low-carbon development throughout the entire life cycle of data centers.

Abstract:Under the background of the new power system,the requirements for the deep peak shaving capacity of coal-fired power units have increased,and solving the low-load stable combustion capacity of units during the peak shaving process has become a research hotspot.Taking the low-load self-stabilizing combustion burner of pulverized coal boilers as the research object,the technical principle of the self-stabilizing combustion burner is introduced,and its combustion characteristics during low-load operation are studied.The results show that the low-load self-stabilizing burner with four combustion stabilization mechanisms,namely reverse jet,swirl,dull body and pre-combustion chamber,can achieve long-term stable combustion of pulverized coal and meet the requirements of the deep peak shaving policy.This burner has advantages in energy-saving,stable combustion at low loads,and meeting the requirements of peak shaving during start-up and shutdown as well as deep peak shaving.

Abstract:Taking a certain industrial park as an example,introducing the application of technologies such as photovoltaic,energy storage,water storage cooling,permanent magnet motor transformation,and water pump transformation from aspects like energy transition,energy-saving and carbon reduction,and circular economy.The results show that the annual power generation of the distributed photovoltaic system reaches 52.409 7 million kWh,exceeding the design value by 16%.The charging and discharging efficiency of the 5 MW/10 MWh electrochemical energy storage system is approximately 85%,saving an annual cost of 3 million yuan.The energy-saving rates of permanent magnet motors and water pump renovations reached 8%and 10.4%to 22.2%,respectively,saving 5.169 million yuan in electricity fees annually.Circular economy technology enables efficient utilization of resources.After comprehensive application,the park can save approximately 52.9 million yuan in operating costs annually and reduce CO2 emissions by 39 700 t.The economic benefits and emission reduction benefits are obvious.

Abstract:Based on the logarithmic mean diadic decomposition(LMDI)model,the driving factors of carbon emissions from terminal energy consumption in Heilongjiang Province from 2010 to 2022 are analyzed,covering carbon emission coefficients,energy structure,energy intensity,industrial structure,economic scale,per capita GDP and population size,and targeted suggestions are put forward.The results show that the decline in energy intensity,the optimization of industrial structure and the reduction in population size from 2010 to 2022 all curbed the increase in terminal CO2 emissions.The expansion of economic scale,the improvement of economic level and the change of energy structure have contributed to the increase of carbon emissions.

Abstract:Aiming at the problems of aging and reduced activity of the returned sludge in the secondary sedimentation tank,a filter for enhancing the activity of the returned sludge is designed based on the optimization method of coupling computational fluid dynamics(CFD)and population equilibrium model(PBM).By simulating the sludge settling process under different structural parameters(the number of inlets,the angle of the cone bucket)and operating conditions(sludge concentration,retention time),determine the optimal structure and operating conditions,and then conduct a pilot test at the sewage treatment plant under the optimal working conditions in summer to systematically analyze and screen the basic parameters,biological activity,pollutant removal capacity and microbial community structure of the sludge.The results show that the 8 DN80 water inlets and the 45° cone bucket angle are the optimal structure,and the operation effect is the best in winter(4 500 mg/L,5 min)and summer(2 000 mg/L,120 min).Compared with imported sludge,the sludge volume index(SVI)of the underflow sludge separated by it decreased by 4.37%,the volatile suspended solids concentration/suspended solids concentration(MLVSS/MLSS)increased by 4.00%,and the aerobic rate(SOUR)is 10.09%higher.The removal rates of chemical oxygen demand(COD)and NH₄+-N increased by 3.99%and 13.62%,respectively.Microbial community analysis further revealed that during the screening process,key functional bacterial communities such as Nitrospirota,Nitrospira and Ellin6067 are significantly enriched,enhancing the nitrification capacity of the system.The effectiveness of the filter in enhancing the activity and treatment capacity of sludge is verified.

Abstract:To enhance the energy efficiency of the zeolite rotor volatile organic compound(VOCs)treatment device,the regeneration temperature parameters are optimized through experiments.The variation laws of VOCs removal effect and equipment energy efficiency under different regeneration temperature conditions are systematically explored,and the appropriate regeneration temperature range is determined.The results show that after applying this optimized temperature parameter,the treatment efficiency of VOCs is significantly improved,energy consumption and greenhouse gas emissions are greatly reduced,and it has a good comprehensive benefit of energy-saving and emission reduction.

Abstract:An evaluation index system for the indoor environment of buildings is constructed from five aspects,indoor thermal and humidity environment,air quality,light environment,sound environment and system energy efficiency,including 15 specific indicators.The analytic hierarchy process(AHP)is combined with the entropy weight method to determine the weights of each index.Subjective judgment is combined with objective information,and the weights are determined through linear weighting.They are integrated into comprehensive evaluation indicators,and a certain office building in Chengdu is taken as the research object for sensitivity and correlation analysis.The results show that the comprehensive evaluation model of AHP-entropy weight method can accurately assess the overall performance of the building indoor environment system,provide an evaluation basis for the collaborative optimization of comfort and energy-saving,and can put forward rectification suggestions based on the evaluation results.It has good applicability and effectiveness.

Abstract:Aiming at the problems of high energy consumption of process air conditioning and high cost of dry steam humidification in cigarette factories,the feasibility of partially replacing traditional dry steam humidification with water curtain wall isenthalpic humidification technology at the fresh air inlet is studied.The results show that the use of isenthalpic humidification in the pre-treatment stage of fresh air can not only meet the strict temperature and humidity requirements of the workshop but also reduce the system energy consumption,demonstrating obvious energy-saving benefits and economic efficiency.During the transitional season,using water curtain walls to pre-humidify fresh air can significantly reduce the energy consumption of the system operation compared with the traditional dry steam humidification method,and has good energy-saving potential.It provides an innovative technical path and practical solution for the energy-saving operation of process air conditioning in cigarette factories.

Abstract:To explore the influence of parameters of the two-stage organic Rankine cycle(DORC)on the system performance,R245fa/R134a is selected as the system's circulating working medium.Based on the DORC cycle,the thermodynamic performance,economic performance and environmental performance models of the system are constructed,and the influence of cycling parameters on the thermodynamic performance,economic performance and environmental performance of the system is analyzed.The results show that when P2 is 3 000 kPa,P3 is 695 kPa,P8 is 1 864 kPa,P9 is 839 kPa,and Teva is 45 K,the thermodynamic performance of the system is in the optimal state.Its exergy efficiency is 28.23%,the thermal efficiency is 10.22%,and the net output work is 18.932 kW.When P2 is 2 200 kPa,P3 is 695 kPa,P8 is 1 864 kPa,P9 is 839 kPa,and Teva is 45 K,the economic performance of the system is the best,the payback period of investment is 2.816 5 a,and the heat exchange area per unit net output work is 10.860 7 m2/kW.When P2 is 3 000 kPa,P3 is 695 kPa,P8 is 1 864 kPa,P9 is 839 kPa,and Teva is 45 K,the environmental performance of the system is in the optimal state,and its annual equivalent carbon dioxide reduction is 4.054 4×105 kg.

Abstract:Establishing a heat dissipation model for overhead pipelines,analyzing the thermal resistance distribution of the pipeline network,and studying the influence of steam flow rate,temperature,insulation thickness,ambient temperature and wind speed on heat dissipation loss.The results show that the thermal resistance of the insulation material accounts for as high as 94.492 4%.Optimizing the thermal conductivity of the insulation material is the key to reducing heat dissipation loss.The steam flow rate has a relatively small impact on the heat dissipation of the pipeline.When the wind speed exceeds a certain threshold,its influence on the heat dissipation gradually weakens.The influence of ambient temperature on heat dissipation loss is relatively small.The influence of steam temperature and insulation thickness is significant.With the increase of pipe diameter,the heat dissipation shows an increasing trend,and its growth rate follows a pattern of being large at first and then small.When the pipe diameter is greater than DN250,the influence of pipe diameter change on heat dissipation weakens.

Abstract:The application effect of a rooftop distributed photovoltaic power generation system with an installed capacity of 1 300.94 kWp in a factory in Huizhou City is studied,with a focus on analyzing its economic benefits and carbon reduction benefits.By constructing a theoretical power generation prediction model and verifying the accuracy of the model based on the actual operation data of the first year.The economic indicators are calculated by using the full life cycle cost analysis method,and combined with the life cycle assessment framework,the publicly available carbon emission factors and regional power grid factors are integrated to quantify the environmental benefits.The results show that during the 25 a operation period of the system,the total predicted power generation can reach 34.652 8 million kWh,the net present value is 5.525 2 million yuan,the internal rate of return is 26.12%,and the dynamic payback period is only 4.68 a.The minimum life cycle carbon reduction benefit is 10 381 tCO2.This project is both economically viable and environmentally friendly,providing a reference for the large-scale application of rooftop photovoltaic systems in industrial plants.

Abstract:Taking a waste incineration plant as the research object,exploring the effect of high-molecular non-catalytic reduction(PNCR)dry denitrification technology in the treatment of waste incineration flue gas.Based on the original'SNCR+SCR'combined process,a PNCR system is added,and the denitration agent spray guns are respectively arranged in the first and second flue ducts.When SNCR and PNCR are put into operation simultaneously,the hourly average NOx emissions are basically below 70 mg/m3,and ammonia escape is less than 4 mg/m3.When SNCR and PNCR are put into operation together,the operating cost is only 17.73 yuan/t.Compared with traditional denitrification methods,PNCR technology has advantages such as high denitrification efficiency(70%to 80%),low operating costs,and simple equipment.However,during operation,attention still needs to be paid to issues such as moisture-proofing and temperature stability of the denitrification agent to ensure the long-term stable operation of the system and the continuous optimization of the denitrification effect.

Abstract:Based on the data of various transportation modes in Jiangsu Province from 2014 to 2022,the carbon emissions of tourism transportation are evaluated by a'bottom-up'approach.The variation characteristics of its time series are analyzed,and the Kaya identity for carbon emissions of tourism transportation is constructed.The logarithmic mean dedehti index(LMDI)method is used to analyze the contribution degree of different factors to the changes in carbon emissions from tourism transportation.The results show that from 2014 to 2022,the carbon emissions of tourism transportation in Jiangsu Province have undergone a three-stage evolution process of'steady growth-sharp decline-fluctuating recovery'.The growth in the number of tourists,the increase in consumption and the efficiency of energy utilization are the main driving factors for carbon emissions in tourism transportation.Economic output and transportation intensity are positive factors in curbing carbon emissions from transportation.Although the energy structure has improved,its effect is limited.The reduction in energy intensity has curbed carbon emissions,highlighting the necessity of accelerating the transition to clean energy.

Abstract:Taking the surface office building of a coal mine in Yulin City,Shaanxi Province as the research object,the carbon emission mechanism during its operation stage is analyzed.By combining energy consumption analysis with data analysis,the effectiveness of measures such as optimizing the envelope structure and enhancing equipment energy efficiency in reducing carbon emissions is verified.A phased renovation strategy of lighting and socket optimization(priority)-upgrade of exterior windows and cold and heat source systems(mid-term)-elevator update as needed(as needed)is proposed.The results show that the energy-saving potential of optimizing the performance of socket equipment,lighting systems and exterior windows is higher than that of the main building envelope(exterior walls,roofs)and elevator systems.For such existing coal mine office buildings,improving the energy efficiency and management level of internal energy-consuming equipment should be given priority over the renovation of the envelope structure.Under economic constraints,the priorities for the renovation of exterior windows and roofs need to be reversed.

Abstract:Taking the waste heat recovery project of a residential area under construction in Xi'an as the research object,gravity heat pipes are adopted to reduce the temperature of the primary return water generated through the heat exchange station.For the selection and design of heat pipe heat exchangers,conventional design methods are chosen and analyzed in combination with actual working conditions.Through design and specification standardization,a 9-row gravity heat pipe heat exchanger is selected for waste heat recovery to enhance the heat exchange efficiency of the heat exchange station,achieve energy-saving and consumption reduction,and lower production costs.The results show that the residual heat recovered by this equipment within one heating period is equivalent to the heat generated by the combustion of 458 006.4 m3 of natural gas,and the energy-saving benefit can reach 998 453.95 yuan.After being put into use,the initial investment cost can be recovered in the first heating season,and the reduction in CO2 emissions can reach 885 266.02 kg.