基于Ebsilon的供热机组灵活性改造研究

Research on Flexibility Modification of Heating Unit Based on Ebsilon

热电联产机组灵活性改造是当前缓解冬季电网调峰压力的重要手段和必然趋势。针对某320MW热电联产机组,基于Ebsilon软件搭建了抽凝供热、低压缸零出力供热、高低压旁路供热的综合供热模型,并采用设计值对模型精度进行了验证。结合模型变工况计算和机组设计资料找出了3种供热方式的运行边界,通过对计算结果的对比分析,得出了3种供热方式下的机组供热能力、发电热耗和调峰能力,结果表明:低压缸零出力和高低压旁路供热方式可以有效提升机组的最大供热量,相比抽凝供热方式,供热能力分别可提升18.7%和54.8%;低压缸零出力供热方式的经济性更优,较抽凝工况的热耗率降低14%~24%,高低压旁路供热方式的经济性最差,较抽凝工况的热耗率升高35%~71%;高低压旁路供热的电调峰能力最优,能够在全供热区间保持32%~35%额定电负荷运行,热电解耦能力突出。研究结果从供热能力、热耗率和调峰能力3个方面为供热机组灵活性改造提供了重要的量化参考依据。

The flexible modification of cogeneration units is an important means and inevitable trend to relieve the peak pressure of power grid in winter.For a 320MW cogeneration unit,a comprehensive heating model was built based on Ebsilon software,which included extraction heating,low-pressure cylinder zero-output heating and high-low-pressure bypass heating.The accuracy of the model was verified by using the design values.The operating boundary of the three heating modes is found by combining the model variable working condition calculation and unit design data.By comparing and analyzing the calculation results,the heating capacity,heat consumption rate and peak regulating capacity of the unit under the three heating modes are obtained.The results show that:Low-pressure cylinder zero-output and high-low-pressure bypass heating can effectively improve the maximum heating capacity of the unit by 18.7%and 54.8%respectively compared with extraction heating.The low-pressure cylinder zero-output heating method has better economic performance,with the heat consumption rate reduced by 14%-24%compared with the extraction heating condition.The high-low-pressure bypass heating method has the worst economic performance,with the heat consumption rate increased by 35%-71%compared with the extraction heating condition.High-low-pressure bypass heating has the best electric peaking capacity,which can maintain 32%-35%rated electric load in the whole heating range,and the thermoelectric decoupling ability is outstanding.The results provide an important quantitative reference for the flexible modification of heating units from three aspects:heating capacity,heat consumption rate and peak regulating capacity.