基于TRNSYS的污水厂沼气热电联产系统优化分析和性能评价

OPTIMIZATION ANALYSIS AND PERFORMANCE EVALUATION OF BIOGAS COGENERATION SYSTEM OF SEWAGE TREATMENT PLANT BASED ON TRNSYS

针对目前污水处理厂污泥处置问题,提出建立以沼气内燃机和工业汽轮机为动力设备、符合能量梯级利用原则的沼气热电联产系统。以青岛市某污水厂为例设计该系统,进行主要设备选型计算,同时基于仿真软件TRNSYS对该系统全年中温运行模式下的热平衡情况进行模拟计算。计算结果表明,在此运行模式下,该系统的排烟温度低于51℃,烟气中的潜热得以利用,可回收的烟气余热量和发电量也大幅增加,系统的能源利用率和效率得到大幅提升。同时,计算系统的投资回收期说明该系统经济上具有可行性。

Aiming at the present sewage treatment plant sludge disposal problems,a biogas cogeneration system is established by combining biogas engine and industrial steam turbine with the sludge anaerobic digestion system to meet energy cascade utilization.Taking a sewage treatment plant in Qingdao as an example,the design calculation and equipment selection are carried out.The simulation software TRNSYS is used to simulate the annual energy consumption of the system under mid-temperature operation.The results show that the flue gas temperature does not exceed 51℃ under this mode,and the latent heat in flue gas is recycled well.The available waste heat and the power generation are increased significantly.Consequently,the energy utilization and the exergy efficiency of the system are improved effectively.Moreover,the payback period of investment is shortened which shows that the biogas cogeneration system in this paper is feasible.