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    Topic on Efficient Utilization of Biomass Energy Resources
  • Topic on Efficient Utilization of Biomass Energy Resources
    Research Progress on Oxygen-enriched Combustion Technology in Biomass Boiler
    DING Xian, LI Wangfan, MA Dafu, WU Helai, LIU Pingyuan
    2024, 44(2): 157-167. https://doi.org/10.19805/j.cnki.jcspe.2024.230672
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    As a new combustion technology, oxygen-enriched combustion can effectively improve the clean utilization of biomass fuel and provide high-concentration CO2 flue gas for carbon capture and utilization. At present, the technology is still in the stage of research demonstration at home and abroad. By systematically sorting out the basic characteristics of biomass fuels, the characteristics of biomass oxygen-enriched combustion and related engineering research status were high lighted, and its development trend of this technology was analyzed. Results show that oxygen-enriched combustion can reduce heat loss and improve combustion stability and boiler operation efficiency to a certain extent. It can effectively control the temperature inside the furnace and alleviate the problem of pollutant emissions by dynamically adjusting the recirculation ratio through flue gas recirculation. There may be technical problems in the oxygen enrichment system, air distribution system, slag formation of the heating surface and the sealing of the whole furnace, etc., and main measures to prevent risks are to select appropriate oxygen injection and oxygen mixing mode, dynamic adjustment of oxygen and air distribution mode, anti-slagging treatment and sealing transformation. The efficient utilization of biomass energy coupled carbon capture and storage technology based on oxygen-enriched combustion is expected to become the direction of the transformation and development of biomass power plants.
  • Topic on Efficient Utilization of Biomass Energy Resources
    Research Progress on Purification Technology for Syngas from Biomass Gasification
    GAO Yali, TIAN Lina, WEI Juntao, YU Guangsuo, WANG Fuchen, HUANG Ankui, XU Deliang, ZHANG Shu
    2024, 44(2): 168-180. https://doi.org/10.19805/j.cnki.jcspe.2024.230537
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    Syngas purification technologies for various pollutants in syngas were mainly reviewed, and the technologies can be classified into hot and cold gas purification according to different treatment methods and different treatment temperatures. For solid particulate pollutants, physical removal is used for both hot and cold gas purification; for tar treatment, physical separation is generally used for cold gas purification, while the methods such as adding catalysts during high-temperature thermal cracking or gasification process are used in hot gas purification; based on a good water-solubility of nitrogenous pollutants, most of cold gas purification technologies use water, acid or organic solvents to absorb directly, while hot gas purification usually uses catalytic oxidation; compared with nitrogenous pollutants, cold gas purification for sulfurated pollutants, not only can use liquid solvents to absorb, but also can use solid adsorbents such as porous carbon materials to absorb, and metal oxides are considered to have good adsorption properties for sulfurated pollutants at high temperatures. For chlorine compounds removal, cold gas purification is applied through following two mechanisms, such as ammonium chloride (NH4Cl) deposition and absorption of hydrogen chloride (HCl) vapor, hot gas purification is applied through metals depositing with halides as halide salts.
  • Topic on Efficient Utilization of Biomass Energy Resources
    Combustion Characteristics and NOx Generation of Hydrochar from Co-hydrothermal Carbonization of Sewage Sludge and Corn Straw
    LEI Haoyang, QIAO Jiafei, WANG Ruikun, ZHAO Zhenghui, YIN Qianqian, GE Lichao
    2024, 44(2): 181-187. https://doi.org/10.19805/j.cnki.jcspe.2024.230550
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    Hydrochar samples were prepared from the co-hydrothermal carbonization of sewage sludge and corn straw under different mass mixing ratios and reaction temperatures. The effects of blending on fuel properties of hydrochar, weight loss and NOx generation of hydrochar combustion were studied. Results show that the hydrochar with higher heating value (HHV) of 15.89 MJ/kg by dried basis can be obtained via co-hydrothermal carbonization. At the same time, part of amino nitrogen and inorganic nitrogen can be removed from the feedstocks, while volatile nitrogen is converted into coke nitrogen with strong thermal stability. In the co-hydrothermal carbonization process, the interaction between proteins and lignocellulosic components can fix nitrogen. With the increase of straw blending ratio in the raw materials, the mass fractions of pyrrole nitrogen, pyridine nitrogen and quaternary nitrogen in hydrochar increase, but the NO generation per megajoule of hydrochar decreases. When the mixing ratio of sludge and straw is 1∶1 and the hydrothermal reaction temperature is 220 ℃, the NO generation per megajoule of hydrochar reaches the lowest, which is 209.8 mg/MJ.
  • Topic on Efficient Utilization of Biomass Energy Resources
    Research on Chemical Looping Co-gasification of Wheat Straw-Coal with CuFe2O4 Oxygen Carrier
    LIN Deshun, DING Ning, LI Weiguang, WANG Baowen
    2024, 44(2): 188-195. https://doi.org/10.19805/j.cnki.jcspe.2024.230502
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    Wheat straw and Indonesian lignite were used as the raw material, the combined oxygen carrier (OC) CuFe2O4 with spinel structure was prepared. The reactivity of the prepared CuFe2O4 combined OC and the synergistic behavior of the co-gasification of wheat straw-Indonesian lignite were studied on the tailored multifunctional reactor with four operation influencing factors being concentrated, including the mixing mass ratio of wheat straw to the lignite, gasification temperature, CuFe2O4 OC excess coefficient and steam input amount. Results show that during chemical looping gasification (CLG) of wheat straw-lignite with CuFe2O4 OC,Cu-Fe ingredients involved in CuFe2O4 promote oxygen transfer and elevate its reactivity. Meanwhile, the carbon conversion and cold gas efficiency (CGE) for the co-gasification of wheat straw-lignite are much higher than those of the single fuel, thus desirable high quality of the gasification products can be produced. Furthermore, the optimized operational factors are determined, including gasification temperature at 950 ℃, OC excess number around 0.2, steam input volumetric flow rate with 0.125 mL/min and the mixed mass ratio of the wheat straw to lignite at 1∶1. Thereby, the syngas yield peak reaches 1.262 m3/kg with H2/CO ratio of 1.69, the carbon conversion of 89.7%, and the syngas selectivity of 63.2%.
  • Topic on Efficient Utilization of Biomass Energy Resources
    Study on the Mixed Pyrolysis Characteristics of Cellulose with Different Crystallinity and 1-Butyl-3-Methylimidazolium Chloride
    ZHANG Tao, PAN Haoxiang, Lü Weizhi, GONG Xun
    2024, 44(2): 196-202. https://doi.org/10.19805/j.cnki.jcspe.2024.230738
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    By means of equal volume wetting, cellulose with different crystallinity was loaded with 1-butyl-3-methylimidazolium chloride (［Bmim］Cl) ionic liquid, and cellulose and regenerated cellulose samples loaded with ionic liquids were obtained. The pyrolysis behavior of ionic liquid-loaded cellulose with different crystallinity was investigated in a fixed-bed reactor, and the three-phase products of biochar, biooil, and biogas were analyzed. Results show that the process of cellulose regeneration can destroy the internal crystal structure, making the amorphous region larger and making dehydration easier to occur. When the pyrolysis temperature is 275 ℃, compared with cellulose, the regenerated cellulose with lower crystallinity can promote the production of volatiles and inhibit the production of solid carbon, and the liquid yield and solid yield will change from 48.23% and 48.81% to 55.7% and 37.67%, respectively. However, at high temperature of 300-350 ℃, the opposite is true. Loading ionic liquid can promote the production of substances such as LGO, with a maximum yield of 16.1%. High crystallinity can promote the catalytic effect of ionic liquid on LGO.
  • Topic on Efficient Utilization of Biomass Energy Resources
    Simulation of an Integrated Biogas Cyclone Separator with Ceramic Membrane Based on Computational Particle Fluid Dynamics (CPFD) Method
    SUN Ruihao, WANG Xiaoyuan, ZHU Yuezhao, WANG Ruofan
    2024, 44(2): 203-212. https://doi.org/10.19805/j.cnki.jcspe.2024.230438
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    To shorten the high-temperature gas dedusting process and improve the collection efficiency, an integrated cyclone separator coupled with composite ceramic membrane was proposed. The flow resistance of ceramic membrane was experimentally investigated at 573 K. The effects of flow rate and pressure on pressure drop of a single ceramic membrane were examined, and the relationship between pressure drop and flow rate was obtained. The gas-solid flow characteristics inside the separator were numerically simulated using computational particle fluid dynamics (CPFD) method. The particles distribution, their velocities and residence time in the biogas dedusting process were examined. The effect of composite ceramic membrane group on pressure drop and collection efficiency of the separator was investigated. Results show that at the inlet temperature of 573 K, pressure of 111 325 Pa, and inlet gas flow rate of 7 909 m3/h, the residence time of dust particles inside the integrated separator is longer than that of the separator without ceramic membrane group. And the particles are captured more efficiently with better aggregation. Its dust collection efficiency increases from 91.2% to 99.7%, while its overall pressure drop increases by 78 Pa.
  • Topic on Efficient Utilization of Biomass Energy Resources
    Simulation Analysis of a New CCHP System Based on Solar-assisted Biogas Chemical Recuperation
    WANG Yilin, SU Bosheng, HUANG Zhi, HUANG Yupeng, HUANG Qiteng, YUAN Shuo
    2024, 44(2): 213-220. https://doi.org/10.19805/j.cnki.jcspe.2024.230449
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    A new combined cooling, heating and power system based on solar-assisted biogas chemical recuperation was proposed. In the new system, the heat load of the biogas digester was considered, and a biogas steam reforming process with high water-carbon ratio was constructed with much water vapor generated by the trough solar energy in medium temperature. Based on the simulation software Aspen Plus, the effects of the key parameter water-carbon ratio on performance of the new and reference systems were analyzed. Results show that the power generation efficiency of the new system is 13.4% higher than that of the reference system in the design condition. With the same cooling capacity, the heating capacity of the new system is 1 476.69 kW higher than that of the reference system, with the increase of 110.62%. Due to the introduction of solar energy, it brings electricity generation benefits, the lowest solar power efficiency(17%) of the new system at a collector temperature of 170 ℃ is higher than the maximum power generation efficiency(16%) of the traditional parabolic system at 300-400 ℃.
  • Topic on Efficient Utilization of Biomass Energy Resources
    Plasma Gasification Based System for Preparation of Levulinic Acid from Municipal Solid Waste and Performance Evaluation
    LIU Zhan, WEI Lai, CHEN Heng, ZHAO Huanlin, PAN Peiyuan, ZHANG Kai
    2024, 44(2): 221-231. https://doi.org/10.19805/j.cnki.jcspe.2024.230745
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    A system for the preparation of levulinic acid (LA) from municipal solid waste was proposed and modeled by Aspen Plus. Waste generation was minimized by recovering the catalyst and extractant of LA and using solid residues (biomass carbon), biogas, and derived fuels from solid waste as heat sources. Heat was supplied to the system through plasma gasification coupled with anaerobic fermentation technology. The performance of the proposed system was evaluated. Results show that the system is technically feasible, has high energy conversion efficiency and low environmental pollution, with a plasma gasification efficiency of 69.94 %, a net present value of 1 894.83 million Yuan, a dynamic payback cycle of 5.04 years, and possesses an internal rate of return of 0.37.
  • Topic on Efficient Utilization of Biomass Energy Resources
    Life Cycle Assessment of Biomass Power-to-Gas Technology
    XUE Yin, DUAN Yufeng, DING Weike
    2024, 44(2): 232-240. https://doi.org/10.19805/j.cnki.jcspe.2024.230497
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    To investigate the environmental impact of biomass power-to-gas technology, two types of biomass, corn stalks and rice straw were selected. The life cycle of biomass power-to-gas technology was comprehensively assessed using the life cycle assessment (LCA) model. By using SimaPro software, LCA was carried out in the stages of biomass harvesting, biomass direct combustion power generation, production of CH4 and H2, transportation and utilization of CH4, to identify the main environmental impact categories at each stage, and a comparative analysis of the environmental impact potentials between corn stalks and rice straw was performed. Results show that marine aquatic toxicity, global warming, freshwater aquatic toxicity and acidification are the more prominent environmental impact categories. In terms of marine aquatic toxicity, the rice straw power-to-gas technology is 2.8 times higher than the corn stalks power-to-gas technology. In terms of environmental impact categories such as global warming, human toxicity and acidification, the impact levels of corn stalks and rice straw are relatively similar.
    • Power Equipment and System
  • Power Equipment and System
    Numerical Simulation of Slagging Characteristics of Ultra Supercritical Double-tangential Circular Fired Boiler Water Wall Under the Combustion of Multiple Coals' Blending
    DONG Lei, CHEN Xi, MA Qilei, XU Min
    2024, 44(2): 241-250. https://doi.org/10.19805/j.cnki.jcspe.2024.230188
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    The slagging characteristics of the water wall of a 1 000 MW ultra-supercritical double-tangential circular fired boiler were numerically simulated, the effect of the combustion of multiple coals' blending on water wall slagging characteristics was investigated and coal blending principles for anti-slagging were proposed. The numerical simulation results show that the double-tangential circular fired boiler forms a reverse tangential double ellipse during combustion, the temperature of the near-burner water wall that the long axis points to is higher, and the slagging tendency is higher. The slagging tendency in each part of the furnace is significantly increased when the proportion of coal I with low calorific value and high ash content is above 40% while blending with the coal Ⅲ with high calorific value and low ash content and the coal Ⅱ with middle calorific value and medium ash content. When the proportion of coal I is under 20%, the boiler operation safety can be guaranteed. The position where coal enters the furnace can significantly affect the position and the rate of particle deposition. It is more reasonable to place the coal with relatively poor properties in the lower burner under the combustion of multiple coals' blending. When the proportion of coals in the furnace is the same, adjusting the position of coal in the furnace can reduce the amount of particle deposition by 10.17%, so as to reduce the slagging tendency of the water wall.
  • Power Equipment and System
    Numerical Simulation of Na/Cl/S-containing Species Evolution and Slagging Propensity of Heat Transfer Walls in a Large-scale Pulverized Coal Boiler
    WANG Yibin, WANG Xiaoxiao, LI Peng, TAN Houzhang, WEI Bo
    2024, 44(2): 251-259. https://doi.org/10.19805/j.cnki.jcspe.2024.230084
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    A slagging model was proposed, in which the multi-step release of Na/S/Cl-containing species from coal, the interacting reaction among gas-phase components, gas-solid reactions and ash particle sticking coupling with salt-vapor condensation were considered. This model could be used to predict the condensation behavior of gaseous alkali metal components on the heating surface inside furnace, the slagging risk for the heating surface and the distribution characteristics of Na-S-Cl components at the furnace outlet. Results show that gaseous Na-containing components mainly exist as the forms of NaO2, NaCl, Na2SO4 and NaOH at the furnace outlet. The slagging risk is high for the water wall from the top burner to the separated overfire air (SOFA) nozzle area and the wall from the bottom burner to the ash hopper corner area. The sticked particles are relatively concentrated at the bottom of the rear platen superheater at the furnace outlet. The slagging rate for the radiant superheaters is much higher than the condensation rate of sodium salt in the gas phase. Whereas the deposition rate of ash particles on the convective heating surface is about 3~4 times of the condensation rate of sodium salt vapor.
  • Power Equipment and System
    Numerical Simulation of Organic Working Medium Radial Inflow Turbine and Study on Internal Flow Characteristics Under Off-design Conditions
    HAN Xu, LI Qi, YANG Yidong, LI Peng, LIU Shuhua, HAN Zhonghe
    2024, 44(2): 260-269. https://doi.org/10.19805/j.cnki.jcspe.2024.230107
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    Based on the research status at home and abroad, 3D numerical simulations were carried out for an organic Rankine cycle turbine under design and off-design conditions respectively. Taking turbine power, efficiency, reaction, stator blade loss coefficient, and rotor blade loss coefficient as evaluation indexes, the performance of the turbine under off-design conditions was analyzed. At the same time, the flow condition of the turbine under off-design conditions was described. Results show that the turbine output power is 122.3 kW and the turbine isentropic efficiency is 83.54% under design condition. While under off-design conditions, the turbine power and efficiency increase greatly when the speed ratio is 0.8-1.0. The reaction coefficient and stator blade loss coefficient of the turbine are linear with the speed, while the rotor blade loss coefficient has a minimum value when the speed ratio is 0.8-1.2. When the rotating speed is lower than the design value, vortices exist on the suction surface of the leading edge of the rotor blade; when the rotating speed is greater than the design speed, vortices exist on the leading edge of the pressure surface of the rotor blade. The main reason for this phenomenon is that there is a difference between the rotating speed of the rotor blade and the circumferential component of the stator blade outlet velocity.
    • New Energy Resources and Energy Storage
  • New Energy Resources and Energy Storage
    Numerical Study on Vortex-induced Vibration of Wind Turbine Airfoil via Prescribed Vibration and Free Vibration
    LI Yu, LIU Can, LIAN Bo, ZHU Xiaocheng
    2024, 44(2): 270-276. https://doi.org/10.19805/j.cnki.jcspe.2024.230074
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    Based on the dynamic mesh technique, the vortex-induced vibration of wind turbine airfoil at 90° angle of attack was numerically studied by using the prescribed vibration method and the free vibration method respectively. Through the prescribed vibration calculation method, the vortex-induced vibration range of Du96-W-180 wind turbine airfoil at different amplitudes was determined, and the effects of changing the incoming flow velocity and changing the structural stiffness on the vortex-induced vibration range were compared. Through the free vibration calculation method, the vortex-induced vibration range of the airfoil at different inflow speeds was obtained. The influence of different structural damping on the vibration response of the airfoil at the frequency ratio r=0.93 and r=1.11 was compared, and the development and evolution process of the vortex-induced vibration of the airfoil were analyzed. Results show that vortex-induced vibration range at different frequency ratios is basically the same while changing incoming flow velocity and changing the structural stiffness. The free vibration numerical simulation verifies the vortex-vibration range of the forced vibration. When 6% structural damping is applied at different frequency ratios, the vibration of the airfoil exhibits two forms: vortex-induced vibration and forced vibration.
    • Digitalization and Intelligentization
  • Digitalization and Intelligentization
    Anomaly Detection Method for Acoustic Signal of Rolling Bearing Based on MFCC and MDE-SVDD
    GAO Yuan, DENG Aidong, FAN Yongsheng, LIANG Zhihong, FU Xingjun
    2024, 44(2): 277-283. https://doi.org/10.19805/j.cnki.jcspe.2024.230091
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    Aiming at the problems that traditional vibration sensor is not easy to install and the acoustic signal analysis is easily interfered by environmental noise, an anomaly detection method for audio signal was used to test the running state of the rolling bearings based on Mel-Frequency cepstral coefficients(MFCC) and Mahalanobis distance weighting support vector data description (MDE-SVDD). In this method, MFCC was extracted from the running sound signal of bearings as the feature vector, and then Mahalanobis distance weighting was used to improve SVDD, so as to enhance the anti-interference of noise samples and improve the detection accuracy of the algorithm. Gaussian white noise of various intensities was added to the experimental sound signal to simulate the field noise environment, and the test results of the proposed method were compared with traditional anomaly detection methods such as SVDD. Results show that the anomaly detection accuracy of MDE-SVDD reaches 91.99% in the scene of low signal-to-noise ratio by -5 dB, which is 7.73% higher than that of the traditional SVDD model.
  • Digitalization and Intelligentization
    Development of a Robotic Measurement System for the Cold Aerodynamic Field Inside Boiler
    KOU Mengnan, LIU Haiyu, NIU Juntian, JIN Yan, WU Yang
    2024, 44(2): 284-291. https://doi.org/10.19805/j.cnki.jcspe.2024.230080
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    Aiming at the problems of low automation and high operation danger of the boiler cold aerodynamic field test, a robotic measurement system for the cold aerodynamic field inside boiler was developed. The lower computer of the system adopted STM32 chip as the main control chip to control the movement of the wall-climbing robot and the information exchange with the upper computer. Meanwhile, the chaos linear inertia weight was introduced to optimize the particle swarm optimization fuzzy PID algorithm. The improved algorithm was used as the control strategy for the robot motion path, and the D-H method was introduced for the control of the robotic arm. Through the embedding dual tree complex wavelet transform denoising algorithm, noise reduction processing of the collected wind speed signal was realized by the operation platform built by the upper computer for LabVIEW. Results show that each module of the proposed system can operate normally and stably, and the error compared to manual test is kept ±10%, which can meet the requirements of boiler cold test.
  • Digitalization and Intelligentization
    Research on a Coordination System Model for Biomass Circulating Fluidized Bed Unit
    GAO Mingming, LIU Botong, ZHANG Hongfu, WANG Yake, YUE Guangxi
    2024, 44(2): 292-300. https://doi.org/10.19805/j.cnki.jcspe.2024.230054
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    Aiming at the biomass circulating fluidized bed (CFB) unit, the dynamic process of biomass combustion was studied through mechanism analysis, and the fuel-side combustion model of biomass CFB boiler was established. Through energy conservation, the functional relationship between the main parameters of the steam-water side and the turbine side of the biomass CFB unit was determined, and the load control system model was established. Based on the actual operation data of a 30 MW biomass CFB unit, the parameters and function relationships of the model were identified by steady-state condition derivation, regression analysis and genetic algorithm. The results of the model were verified on the Simulink platform and the model step test was carried out. Results show that the output of the model well matches the actual data. The average relative errors of the main steam pressure and load are within 4%. The step response conforms to the actual experience, which proves that the established model can reflect the dynamic characteristics of the unit.
    • Green Energy and Low-carbon Technology
  • Green Energy and Low-carbon Technology
    Comparison of Trace Elements in Desulfurization Products by Limestone Method and Ammonia Method
    WANG Mingwei, XIAO Haiping, WU Haitao, GUO Zhengwang
    2024, 44(2): 301-306. https://doi.org/10.19805/j.cnki.jcspe.2024.230116
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    In order to realize resource utilization of desulphurization products and assess environmental risks of ammonium sulfate and desulphurized gypsum, the content of heavy metals in the whole plant was analyzed, and the occurrence and leaching characteristics of heavy metals in the desulfurization products were studied. Results show that the content of Cu and Cr in ammonium sulfate is less than 1%, much lower than that in gypsum. The content of Mn and Sn in gypsum and ammonium sulfate differs by more than 6 times, probably due to the weak acidity of Mn and Sn ions. The content of As and Pb in gypsum produced by different furnace types can be as high difference as 5 times, while the distribution of Se, Cd and Ba is not affected by the furnace type and desulfurization technology. The leaching concentration of Cr is maximum, about 2.04% of the standard limit. Se with Ca2+ and Cu are deposited in desulfurization gypsum in the form of CaSeO3 precipitate and CuFe2O4, respectively. The leaching level of heavy metals in ammonium sulfate is higher than that in desulfurization gypsum, but the emission and leaching concentration of heavy metals in the tests are far lower than the current standard limits, so the resource utilization of desulphurization products is safe and feasible.
  • Green Energy and Low-carbon Technology
    Thermal Economic Analysis of 300 MW Supercritical Carbon Dioxide Coal-fired Generating Units
    BAI Yaping, YANG Yilin, LI Peng, HAN Zhonghe, CHEN Dongxu, GUO Dongyang
    2024, 44(2): 307-316. https://doi.org/10.19805/j.cnki.jcspe.2024.230064
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    A thermal economic mathematical model was established for a 300 MW supercritical carbon dioxide (SCO2) partially cooled cycle and partially cooled reheated cycle coal-fired power generation system. Using cycle thermal efficiency ηt, system exergy efficiency ηex and levelized electricity cost CLCOE as evaluation indicators, to conduct thermal economic comparative analysis on different systems and key parameters. Results show that under design conditions, ηt is 0.33% higher and ηex is 0.35% higher at partial cooling reheat cycles compared to partial cooling cycles. Under the same parameter conditions, the coal consumption cost of both generator units exceeds 70%, and the boiler cost is much higher than the cost of other equipments. There exists optimal inlet pressure for the main compressor, such that ηt and ηex reach the maximum, while CLCOE reaches the minimum. As the inlet temperature of the main compressor increases, ηt and ηex gradually decrease, while CLCOE gradually increases. ηt and ηex increase linearly with the increase of turbine inlet temperature, while CLCOE first decreases and then increases.
  • Green Energy and Low-carbon Technology
    Research on Optimal Scheduling Method of Distributed Energy System Based on Multi-energy Storage
    HAN Zhonghe, MA Li, DUAN Yuxuan, LIU Ao, WU Di, LI Guiqiang
    2024, 44(2): 317-327. https://doi.org/10.19805/j.cnki.jcspe.2024.230002
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    In order to further build a clean, low-carbon, economical and energy-saving energy supply system, a distributed energy system with wind, solar and multi-energy storage was established. For an office park in Beijing, DeST simulation software was used to predict user load and local wind and solar conditions. An adaptive optimal operation strategy was proposed to maximize the comprehensive benefits of economy, energy-saving and environmental protection. The exhaustive search method and genetic algorithm were used to optimize the optimal scheduling scheme of the system. Meanwhile, using the electric heating operation strategy as a comparison, the comprehensive benefits of the system under several different operation strategies were compared and analyzed. Results show that the average comprehensive benefit under the traditional following electrical load operation mode is 0.41 on average; under the adaptive optimization operation strategy, the average comprehensive benefit of the scheduling scheme obtained by genetic algorithm can reach 0.5, and the average comprehensive benefit of the operation scheme obtained by the exhaustive search method can reach 0.51.
  • Green Energy and Low-carbon Technology
    Optimal Design and Thermal Performance Analysis of Combined Power Generation System Based on Gas Turbine Waste Heat and Geothermal Energy
    FU Wenfeng, WANG Jinying, WANG Lanjing, YANG Le
    2024, 44(2): 328-338. https://doi.org/10.19805/j.cnki.jcspe.2024.230097
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    A new type of combined power generation system was designed, which integrated the S-CO2 recompression system and the geothermal double flash system. The effects of internal and boundary parameters on the net maximum output power and waste heat utilization rate were calculated and analyzed using genetic algorithm based on the parameter optimization model of the combined system. Results show that optimizing system parameters can achieve a reasonable distribution of waste heat in the two subsystems and cascade utilization of gas turbine waste heat. When the primary flash pressure is 99.89 kPa, the secondary flash pressure is 29.4 kPa, the S-CO2 flow rate is 22.68 kg/s, and the split ratio is 0.308 5, the maximum net output power of the combined system is 6.402 MW, the corresponding waste heat efficiency is 67.9%. When the primary flash pressure is 90-115 kPa and the secondary flash pressure is 25-35 kPa, the combined system can achieve high net output power, with a relative deviation from the optimal value within 0.8%. The net output power of the combined system shows a pattern of increasing first and then decreasing as the S-CO2 mass flow rate or split ratio increases. The maximum net output power of the combined system increases with the increase of S-CO2 turbine inlet pressure and decreases with the increase of S-CO2 turbine outlet pressure and precooler outlet temperature.