内燃机余热驱动的超临界CO_(2)循环非设计工况性能分析  

Performance analysis on supercritical CO_(2) power cycle for internal combustion engine waste heat recovery under off-design conditions

作　　者：张旭伟 郭子岗 王鑫华 张一帆[1] 蒋世希 顾正萌[1] ZHANG Xuwei;GUO Zigang;WANG Xinhua;ZHANG Yifan;JIANG Shixi;GU Zhengmeng(Xi'an Thermal Power Research Institute Co.,Ltd.,Xi'an,710054,China;Shaanxi Yulin Energy Group Yushen Coal Power Co.,Ltd,Xi'an,719000,China)

机构地区：[1]西安热工研究院有限公司,陕西西安710054 [2]陕西榆林能源集团榆神煤电有限公司,陕西榆林719000

出　　处：《电力科技与环保》2023年第6期484-489,共6页Electric Power Technology and Environmental Protection

基　　金：陕西省创新能力支撑计划项目(2023-CX-TD-18)。

摘　　要：超临界二氧化碳动力循环是一种回收内燃机排气余热的重要方式。为了揭示回收内燃机余热的超临界二氧化碳动力循环在非设计工况下的运行特性,基于热力学第一定律,建立了压缩机、透平、换热器、阀门等系统关键设备的非设计工况热力计算模型,进而构建了整个循环的非设计工况计算模型,并对非设计工况下循环热力学性能进行了分析。结果表明:设计工况下,循环热效率和输出净功率分别为45.00%和200 kW;相比于设计工况,当主压缩机入口温度升高到40℃时,循环热效率和净功率分别降低到11.54%和24.50 kW;当透平入口温度降低到450℃时,循环热效率和净功率分别降低到39.00%和162.43kW;当主调阀阻力增加到6.84 MPa时,循环热效率和净功率分别降低到37.18%和116.97 kW;针对两种系统负荷调节方式,当负荷率由100%降低到60%时,转速控制方式和阀门控制方式下,循环热效率分别降低至44.25%和38.00%。总体上,主压缩机入口温度的升高、透平入口温度的降低和主调阀阻力的增大均会导致循环性能降低;其中,主压缩机入口温度变化对循环性能影响剧烈,故应尽可能维持在设计温度运行;转速控制方式调节系统负荷时,系统循环性能变化较小,具有较高的热经济性。The supercritical carbon dioxide(CO_(2))power cycle is an important way to recover the exhaust heat of internal combustion engines.To reveal the operating characteristics of the supercritical CO_(2) power cycle for recovering waste heat from internal combustion engines under off-design conditions,based on the first law of thermodynamics,the off-design thermal calculation models of compressors,turbines,heat exchangers,valves and the whole cycle are established,and then the thermodynamic performance of the cycle under off-design conditions is analyzed.Results show that under the design condition,the cycle thermal efficiency and net output power are 45.00% and 200.00 kW,respectively.Under the off-design condition,when the main compressor inlet temperature is increased to 40.00℃,the cycle thermal efficiency and net power are reduced to 11.54%and 24.50 kW.When the turbine inlet temperature is reduced to 450.00℃,the cycle thermal efficiency and net power are reduced to 39.00% and 162.43 kW.When the main control valve resistance increases to 6.84 MPa,the cycle thermal efficiency and net power are reduced to 37.18% and 116.97 kW.When the load rate is reduced from 100% to 60%,the cycle thermal efficiency is reduced to 44.25% and 38.00% respectively under the speed control mode and valve control mode.In summary,the increase of the main compressor inlet temperature,the decrease of the turbine inlet temperature and the increase of the main control valve resistance all lead to the decrease of the cycle performance.Among them,the temperature changes at the main compressor inlet dramatically affects cycle performance,so it should be maintained at the design temperature as much as possible.When the speed control mode adjusts the system load,the system cycle performance changes less,and the mode has higher thermal economy.

关 键 词：超临界二氧化碳 动力循环 内燃机 余热回收 非设计工况 

分 类 号：TK401[动力工程及工程热物理—动力机械及工程]