摘要
热电联产机组以热定电的运行方式限制了其深度调峰能力,熔盐蓄热技术能够提高机组运行灵活性,在一定程度上实现了热电解耦。以耦合可对外供热熔盐蓄热系统的某660 MW热电联产机组为研究对象,提出了一种安全供热运行边界的计算方法,基于该安全域计算分析了解耦与调峰能力的变化,并对储、放热过程中的能量利用效率与[火用]效率进行了分析。结果表明:所提出的边界计算方法精确,能够确定耦合系统供热时的电热定值约束;80 MW·h熔盐蓄热系统可提供260℃、2 MPa的供热蒸汽最大质量流量为65.92 t/h,提高的深度调峰量最大值为额定负荷的7.56%;能量利用效率随着机组抽汽供热质量流量的增大和发电功率的减小而增大,[火用]效率随着抽汽供热质量流量和发电功率的增大而增大,储热功率为最大值(36 MW)时,机组在运行域内的能量利用效率与[火用]效率最高,分别为79.78%和46.04%,熔盐放热过程产生的蒸汽质量流量最大时,机组运行域内能量利用效率与[火用]效率最高,分别为80.84%和46.33%;在供热质量流量分配时优先释放机组抽汽供热能力再辅以熔盐蓄热系统供热,具有更高的能量利用效率和[火用]效率。
The"power determined by heat"operation mode constrains the deep peak regulation capacity of combined heat and power units.The molten salt heat storage technique can enhance the operation flexibility of power unit,and achieve the decoupling of heat and power to a certain extent.Taking a 660 MW combined heat and power unit coupled with a molten salt heat storage system that can supply heat as the research object,a calculation method for the safe heating operation boundary was proposed.Based on this safety domain,the changes in decoupling and peak-shaving capabilities were calculated and analyzed,and the energy utilization efficiency and exergy efficiency during the heat storage and release processes were also analyzed.Results show that the proposed boundary calculation method is accurate and can determine the constraints on the fixed values of power and heat when the coupled system supplies heat.The 80 MW·h molten salt heat storage system can provide heating steam at 260℃ and 2 MPa with a maximum mass flow rate of 65.92 t/h,and the maximum increase in deep peak-shaving capacity is 7.56% of the rated load.The energy utilization efficiency increases with the increase in the mass flow rate of the unit's extraction steam for heating and the decrease in power generation,while the exergy efficiency increases with the increase in both the mass flow rate of extraction steam for heating and the power generation.When the heat storage power reaches its maximum value(36 MW),the unit achieves the highest energy utilization efficiency and exergy efficiency within the operation domain,which are 79.78% and 46.04%,respectively.When the mass flow rate of steam generated during the molten salt heat release process is the maximum,the unit's energy utilization efficiency and exergy efficiency within the operation domain reach the highest levels,being 80.84%and 46.33%,respectively.In terms of the distribution of heating mass flow rate,giving priority to utilizing the unit's extraction steam heating capacity and then supplementing with the molten salt heat storage system results in higher energy utilization efficiency and exergy efficiency.
作者
谢凯
王乾
苏志刚
郝勇生
王培红
XIE Kai;WANG Qian;SU Zhigang;HAO Yongsheng;WANG Peihong(School of Energy and Environment,Southeast University,Nanjing 211189,Jiangsu Province,China;School of Energy and Power Engineering,Jiangsu University of Science and Technology,Nanjing 212100,Jiangsu Province,China)
出处
《动力工程学报》
北大核心
2025年第9期1546-1556,共11页
Journal of Chinese Society of Power Engineering
基金
国家自然科学基金资助项目(52076037,51476028)。
关键词
热电联产机组
熔盐蓄热
运行边界
灵活性
热力性能
combined heat and power unit
molten salt heat storage
operation domain
flexibility
thermodynamic performance
作者简介
谢凯(2000-),男,湖北襄阳人,硕士研究生,研究方向为燃煤机组灵活性运行;通信作者:王培红,男,教授,博士生导师,E-mail:phwang@seu.edu.cn。
