沼气热电联产耦合吸收式热泵的系统性能

System performance of coupled absorptive-type heat pump for biogas heat-electricity cogeneration LI Jin-ping^(1,2,3), FENG Chen^(1,2,3), CAO Gang-lin^(1,2,3)

为解决大中型沼气工程供能不足的问题,以兰州某80 kW沼气热电联产工程为例,构建了一套耦合双效溴化锂吸收式热泵系统.运用Aspen Plus软件建立了双效溴化锂吸收式热泵模型,并对热电联产余热利用方式进行了优化.结果表明:耦合系统实现能量综合梯级利用,同时保证寒冷季节维持发酵温度35℃,与原系统相比增加供能4 390.92 MJ/d,系统综合效率0.99,与燃煤锅炉供能方式相比,每年可节约标煤12.45 t,节省费用14 900元,减少二氧化碳排放31.12 t;其他季节增加制冷量2 662.92 MJ/d,节约电费36 500元,系统综合效率0.8,该耦合系统可使发酵系统在不同季节均保持恒温厌氧发酵,保证稳定运行.

In order to solve the problem of shortage of energy supply in large-and medium-scale biogas projects,a 80 kW heat-electricity cogeneration project with biogas in Lanzhou is taken as an example to build a set of coupled double-effect lithium bromide absorptive-type heat pump system.Software Aspen Plus is chosen to establish the model of this heat optimize pump and utilization way of waste heat for cogeneration of the project.The result shows that with this coupled system,a comprehensive cascade utilization of energy can be implemented,the fermentation temperature of 35 ℃ will be guaranteed in cold season,the increment of energy supply from that of original system will be 4390.92 MJ/d,and the system comprehensive efficiency will be 0.99.Compared to energy supply way with coal-fire boiler,the established system can save standard coal of 12.45 t and its cost of 14900 CNY,reduce the emission of CO2 of 31.12 t each year.The established system will augment refrigerating capacity of 2662.92 MJ/d in hot season,saving electric charge of 36500 CNY and the system comprehensive efficiency will be 0.8.The coupled system can be used to realize thermostatic fermentation and make the operation stable in different seasons,so that the coupled system will be feasible and provide a reference for the design and optimization of the utilization of waste heat from biogas power generation.