再生水源热泵应用于污泥厌氧处理的能流分析

Analysis on energy flow of sludge anaerobic digestion system equipped with reclaimed water source heat pump

污水处理产生的污泥中含有大量有机物质容易腐败成为新的环境污染源,污泥高温厌氧消化是解决污染并实现污泥资源化的有效途径,但处理工艺的高能耗成为限制厌氧消化系统推广应用的瓶颈问题。通过将再生水源热泵应用到污泥消化流程中,提出了一种适合现阶段我国污水处理厂的能源综合利用技术路线。再生水源热泵回收污水处理厂外排再生水所含低温余热,将其提升后满足污泥高温厌氧消化供热要求,同时厌氧消化工艺产出沼气,可供给用做污水处理曝气流程的风机动力源。能流分析表明,再生水源热泵的应用可有效降低污泥厌氧消化处理的能耗,所产沼气可替代污水曝气处理流程中鼓风机40%电耗。

Sludge easily become a new environmental pollution source if not treated properly. As a recommendation method of sludge disposal, thermophilic anaerobic digestion process can remove organic pollutants effectively, but high energy consumption in the process has greatly influenced the application of the treatment. This paper presents a comprehensive approach of energy utilization; the reclaimed water source heat pump is introduced into the process of sludge digestion, which reuses the municipal reclaimed sewage as the heat source to supply the heating need in the thermophilic anaerobic digestion process, meanwhile, the biogas generated from the sludge digestion in wastewater treatment plants is a potential clean energy source, which can be recycled to driving blowers coupled with a biogas driven engine and to saving 40% energy consumption. From the perspectives of energy balance, cascaded utilization of energy and pollutant emission, three kinds of heating modes, coal - fired boiler, gas - fired boiler and water source heat pump was compared in this paper. Based on the calculation results, the new appronch has the features of low energy consumption, rationality of energy utilization, and environment- friendliness.