Analysis Of Anaerobic Reactor Heating System Based On Biogas And Energy Recovery

Anaerobic treatment technology is a commonly used anaerobic biological treatment technology to treat starch wastewater.In order to maintain high processing efficiency and gas production rate,its temperature needs to be kept at 35?,while the temperature is the water temperature of imported waste water and the temperature of the surrounding environment of the reactor are generally lower than 35?,so the reactor will have loss of heat.If there is no heating and insulation measures,the temperature will drop and the demand will not be met.In view of the above problems,this paper studied the energy loss and heat production of the anaerobic reactor when it was used to treat starch wastewater.This paper first established an energy balance model for anaerobic reactors.The model quantitatively calculates two heat losses in an anaerobic reactor:the amount of cooling carried by the imported wastewater and the loss of heat from the reactor to the surrounding environment,and the anaerobic reactor.The microbes in the fermentation produce heat.Taking a UASB reactor in Fuyang City,Anhui Province as the research object,it is found that the heat loss of the UASB reactor mainly comes from the amount of cold imported by its imported waste water,accounting for more than 94%of the total heat loss in each month.The maximum value appears in In February,it was 752.07 kW;however,the UASB reactor's heat loss to the surrounding environment accounted for only 6%or less,with the maximum occurring in February at 41.23 kW.Therefore,ignoring the loss of heat to the surrounding environment and considering only the amount of cold carried by the UASB reactor inlet waste water has little effect on the heating effect of the UASB reactor.In order to study efficient and reasonable heating for anaerobic reactors,a heating system biogas generator-wastewater source heat pump was designed in this paper.This system can use biogas from anaerobic reactors to generate electricity and then drive the sewage source heat pump.Moreover,there is a water cycle in the system to recover the waste heat of the biogas generator set,and the sewage source heat pump can also recover the waste heat of the effluent from the anaerobic reactor so that the energy can be used efficiently.According to the difference in the imported wastewater temperature of the UASB reactor's,the system operates in different modes and consumes different energy types and quantities.The operation mode of the system is divided into direct heating of export waste water and heat recovery of biogas generator units and heating imported waste water,and biogas power generation unit combined with sewage source heat pump.This article has carried on the preliminary design to the main equipment of this system,then through simplification some parameters and the operating condition of this system,establishes the main equipment the mathematical model,carries on the better optimization to the system.The effects of evaporation temperature and condensing temperature on the performance of the sewage source heat pump system were analyzed,and the optimum evaporation temperature and condensing temperature values were obtained.Based on the properties of the inlet and outlet fluids such as temperature and flow rate,a shell-and-tube heat exchanger was established and evaporated.The design model of the condenser and condenser was simulated using MATLAB,and the dimension parameters of the four heat exchangers and the distribution arrangement of the heat exchange tubes were obtained.In order to quantify the energy saving and economical efficiency of the biogas generator-sewage source heat pump heating system,the author takes a UASB reactor in Fuyang City,Anhui Province as the research object,and compares it with the energy consumed by a biogas boiler as a single heat source.For biogas generators.-Comparing the sewage source heat pump heating system with the biogas boiler,it can be concluded that compared with the heating method of the biogas boiler,the biogas generator unit combined with the sewage source heat pump system is an energy-saving and economical system in terms of energy saving,and the biogas boiler as a single heat source Compared with the method,the energy-saving effect of this system is significant.The primary energy saved is 163.00kW to 347.20kW.In November,the energy saved is the most,while in July,the energy saved is the least,and the average energy saved in the whole year is saved.The amount is 259.02kW,and the effect is remarkable.From the aspect of economy,the annual value of the cost of the composite source heating system is RMB 718,400,and the annual value of the cost of the biogas boiler and electric heating is RMB 997.3 thousand.In addition,it can be seen from the operation mode of the biogas generator-sewage source heat pump heating system that the equipment of each system,and their optimization process that the biogas generator-sewage source heat pump heating system has universal applicability to the heating of the anaerobic reactor.Some of the operating parameters of the system can be modified and optimized to heat the other two generations of anaerobic reactors.