Capacity Maximization Method Research On Household Combined Heating, Power And Biogas System

The household thermoelectric system consists mainly of a solar water heater array,a photovoltaic power-generation/storage device,and a solar temperature controlled biogas pool.It can satisfy the multilevel energy demand such as cooking gas,household electricity and heating energy of single farmer continuously and steadily,and has wide application prospects in rural areas.The results of the previous research show that the system has a relatively stable biogas production throughout the year.The energy generated by solar energy heating and hot water and photovoltaic is still severely constrained by the coupling of various environmental factors.The effective utilization rate is very low,and the system integration method and operation strategy need to be improved.Therefore,it is significant to reveal the coupling influence mechanism of various environmental factors on the system,and to improve the system integration method and operation strategy.Therefore,in this paper,the single factors such as ambient temperature,solar radiation and wind speed affect the production capacity performance of the system by means of experimental research and theoretical analysis.This paper constructs and verifies the relationship between the couplings of these factors to the system capacity analyzes and determines the cooperative complementary model of multiple subsystems,and obtains the method of maximizing the production capacity of the household thermal power supply system.1.The influence mechanism of single factors such as ambient temperature,solar radiation and wind speed on system capacity performance is studied by means of experimental research and theoretical analysis.In the absence of the influence of solar radiation,the ambient temperature rises by 1?and the water temperature of the tank rises by 2.2?;the ambient temperature is in the range of-25~0?,the wind speed is in the range of 0~8m/s,the solar radiation intensity increases by 1W/m~2,the water temperature in the tank increases by 0~0.03?,and the ambient temperature is in the range of 0~15?.The solar radiation intensity is less than 500W/m~2,and the water temperature of the water tank of the solar collector group and the single heater water temperature of the solar solar anaerobic fermentation subsystem basically changes with the solar radiation.When the solar radiation intensity is in the range of500~1100W/m~2,the water temperature of the water tank change by 0~0.04?with each increase in the solar radiation intensity of 1W/m~2.No change in solar radiation and ambient temperature,the wind speed less than 4m/s does not have any effect on the performance of the system,and when the wind speed is greater than 4m/s,the temperature of the solar collector tank decreases by 0~0.08?for each increase of 1m/s.And the time when the wind speed is greater than 4m/s accounts for only 3.77%of all test time,and the time is very short,which has very little impact on system production capacity and system efficiency.Within the set fermentation temperature range,for each increase of 1?in the water temperature of the solar collector tank,the production volume of the solar anaerobic fermentation subsystem increased by 0.06±0.03m~3,the environmental temperature increased by 1?,and the solar anaerobic fermentation subsystem increased by 0.07±0.03m~3.2.Constructed and verified the coupling effect of these factors on system capacity.According to environmental factors,the error between the water temperature calculation formula of the heat collector group and the actual test water tank temperature measured is only±0.97%;The output power of the solar photovoltaic module and the solar irradiance are fitted to obtain a linear equation trend line of 0.94 for the correlation R~2,indicating that the fitting correlation is high,and the output power of the photovoltaic system is calculated based on the solar radiation intensity.3.The cooperative complementary model of multiple subsystems is analyzed and determined.(1)Due to the limitations of the energy storage device,the photovoltaic system can not completely store the electrical energy produced every day.Part of the electrical energy that can not be stored and used is lost to the air in the form of heat energy.Extending the running time of the pump to recycling the energy and extend the heating time of the solar heating subsystem.It can provide an additional 3.54kWh of heat per day for the interior,and the solar energy guarantee rate for heating can be increased to 74.49%.Single heating like provides 425.04kWh of heat.(2)Solar biogas fermentation subsystem with solar temperature control provides heat and the solar collector with temperature control.The heat collected by solar collectors is used to maintain a constant temperature.The heat needed for anaerobic fermentation is surplus every day.Heat that can not be used is lost in the air in the form of heat,causing serious waste.Combined with prolific electrical energy,the heat transfer frequency of heat collection and radiator is strengthened,and heating like provides2338.90kWh of heat energy.Heat can also be further used to increase the fermentation temperature of the solar thermal anaerobic fermentation subsystem and increase the amount of production.(3)Under the same solar radiation intensity,wind speed and ambient temperature conditions,the heat dissipation and radiation dissipation of a single solar collector is smaller than that of a solar collector group throughout the day,and the effect of mixing is reduced by changing the connection mode.The entire heating season can reduce heat loss by 85.68kWh.4.The method of maximizing the production capacity of household thermal power supply system is obtained.Change the connection mode to reduce the energy loss,and use the solar energy collector of the solar temperature controlled biogas fermentation subsystem to ensure the remaining heat after the fermentation temperature.Combined with solar photovoltaics,the energy produced by solar photovoltaics system is used to supplement and regulate solar energy heating subsystem.While improving energy efficiency,the system can not avoid being affected by external environmental factors,but the greater the degree of synergy between the various subsystems,the better the stability of the system.Changes in environmental factors will not have much impact on the performance of the system.After the operation strategy and energy loss optimization,winter heating Jike provides more energy of 2850.39kWh,equivalent to 347.32kg of coal.The innovation of this article is:1.Experiments and theories have revealed the influence mechanism and coupling mechanism of single factors such as environmental temperature,solar radiation,and wind speed on the production capacity of household thermal and electrical systems.The theory has determined the influence range of single environmental factors on the production capacity performance of the system.2.The cooperative complementary model of solar water heater array,photovoltaic power generation/storage device and solar thermostatic biogas pool was determined,and the method of maximizing the production capacity of household thermal electric joint supply system was obtained,which provided theoretical guidance for further improving the stability and economy of system production capacity.