华电电力科学研究院有限公司

[Objectives]In large-scale multi-energy complementary bases,there are multiple types of resources,significant fluctuations in new energy output,complex operating conditions,and diverse demands of owners,leading to great challenges in the actual operation optimization.Therefore,it is necessary to design and develop operation scheme of the wind-solar-thermal-storage coupled system according to engineering practice.[Methods]The operation model of large-scale new energy bases is established.Taking economic efficiency,carbon emission,load fluctuation rate,and new energy accommodation rate as the core optimization objectives,this study examines the three-stage multi-mode operation optimization scheme by comprehensively considering various operation requirements and equipment flexibility under different time scales.Combined with actual engineering cases,the typical days of the year and each season are analyzed to verify the effectiveness of the scheme.[Results]The dispatching method can effectively balance multiple optimization objectives,give consideration to equipment flexibility and diverse requirements,and improve the economic efficiency and operational friendliness of large-scale new energy bases.[Conclusions]The proposed scheme can effectively solve the multi-mode and multi-stage problems of large-scale new energy base operation optimization.It is suggested that the operators sign power export curve contracts based on the output characteristics of new energy in different seasons to improve the economic efficiency.The research results can provide engineering case reference and technical support for operation of the same type of large-scale new energy bases.

The existing mechanism models for thermal power units face challenges in accurately reflecting unit response characteristics and obtaining precise model parameters. This paper proposes a data-driven modeling method for secondary frequency regulation characteristic of thermal power units. First， the frequency regulation response characteristics of automatic generation control （AGC） are analyzed， and operational conditions are categorized based on regulation intensity. Using multiple sets of secondary frequency response curves under similar regulation intensities， the least squares method is applied to extract the response features of secondary frequency regulation. Next， a second-order model represents the mathematical model of the units， with online adjustments to the model's damping coefficients to enhance adaptability to changes in regulation intensity. Adaptive parameters for the three response stages during the unit's response process are determined using particle swarm optimization （PSO）. Finally， case studies are designed to validate the effectiveness and superiority of the proposed model.

[Objectives]Under the background of the"dual-carbon"strategy and the global energy structure transition,achieving high-efficiency and low-carbon operation of conventional energy systems is a pressing challenge that needs to be overcome.To address this,an low-carbon-emission combined cooling,heating,and power(CCHP)system coupled with heat pump(HP)technology is proposed.[Methods]A multi-stage waste heat recovery and temperature-zone coordinated matching mechanism is employed to optimize the energy cascade utilization pathway.A multi-dimensional evaluation model,covering thermodynamics,environmental friendliness,economic efficiency,and exergoeconomic performance,is established and compared with the performance of conventional systems.[Results]The results of economic analysis show that the heat-pump integration increases the unit power generation cost from 1.24 to 1.43 yuan/(kW·h),but reduces the unit capacity cost from 0.24 to 0.22 yuan/(kW·h),resulting in an overall improvement in energy efficiency.The sensitivity analysis results reveal that operating duration and interest rate have the greatest impact on costs.Exergoeconomic analysis indicates that the turbine,carbon capture and storage(CCS)system,and compressor contribute 67.019％,17.107％,and 8.169％of the exergy loss,respectively,representing the core directions for future optimization.[Conclusions]These research findings provide a theoretical basis for the design and promotion of low-carbon-emission CCHP systems.

Salinity waste water is characterised by complex pollution components,high treatment costs and difficulties,and improper treatment can cause serious ecological damage.Incineration is a harmless disposal method of salinity waste water,but because the alkali metal salts in salinity waste water may cause the ash melting temperature to decrease,result-ing in corrosion of incineration equipment and accumulation of ash slag and other problems.Therefore,it is necessary to study the effects and mechanisms of common salts in saline wastewater and coal blending combustion process on the melt-ing characteristics of coal ash.Three common salts NaCl,Na2SO4,and NaNO3 from saline wastewater were loaded into two kinds of combustion coals by impregnation method and ash production was carried out at a temperature of 815℃ to obtain ash samples from different coal samples.Ash melting point tests were performed for ash samples loaded with dif-ferent sodium salts.It was found that under 3%sodium salt blending ratio,NaCl,Na2SO4 and NaNO3 blending will signi-ficantly reduce the coal ash melting temperature,resulting in coal ash slagging.The deformation and softening temperat-ures of coal 1 were both highest when loaded with Na2SO4 and lowest when loaded with NaCl.Meanwhile,after loading the three sodium salts on Coal 1,Rz was greater than 2.5,and all of them had a tendency to severe slagging.Effect of NaCl on the ash melting temperature is particularly significant,and it will produce by-products of HCl,resulting in the corro-sion of heated surfaces,and the effects of Na2SO4 and NaNO3 on different coal types are slightly different.In addition,the elemental composition of the ash samples showed an increase in the total content of the alkali metal elements Na,Fe,and Ca in the ash particles as compared to that in the absence of sodium salt loading.According to the scanning electron mi-croscopy and X-ray diffraction analysis,there was an obvious bonding phenomenon between coal 1 ash-NaCl particles and particles,and low melting point substances such as NaAlSiO4 and KNa3(AlSiO4)4 were also generated in the ash samples,and they may further form a low-temperature eutectic,which resulted in the susceptibility to slagging during the combus-tion process of the NaCl-loaded coal samples.Therefore,when the concentrate or crystallized salt of salt-containing wastewater and coal are mixed and burned,the mixing ratio must be strictly controlled,especially for wastewater with high NaCl content.

The power sector is the largest single source of carbon dioxide emissions in China,and its low-carbon transition is a pivotal lever for achieving the dual carbon goals.However,there remains a lack of focused studies on the low-carbon transition of power generation enterprises in the existing literature.To address this gap,this paper constructs a corporate low-carbon transition planning model integrating multidimensional factors including technological,economic,and environmental considerations.It analyzes the decarbonization pathways for power generation enterprises to achieve carbon neutrality by 2060 under the current policy.Furthermore,it conducts comparative simulations of several low-carbon transition scenarios for future power companies.The findings indicate that,for power generation enterprises,advancing carbon neutrality moderately ahead of schedule can yield certain benefits,but overly aggressive timelines may lead to steep cost escalations.Additionally,future policies are likely to drive increased energy storage deployment,necessitating preparatory technological and resource investments in relevant enterprises.Finally,the paper proposes solutions for decommissioned coal-fired power units,recommending their retrofitting or the integration of carbon capture and storage(CCS)technologies,which could be assigned roles in grid peak-shaving and emergency backup.