Research On Energy System Optimization Of Rural Residential Buildings Based On Dynamic Operation Strategy

The express urbanization of rural areas in Northwest China underlines the tension between changing rural energy lack and finite regional energy supplies.Northwest China is rich in solar energy resources.And the rural areas in Northwest China have more land and space resources.The mode of solar distributed energy system is a potential solution to the conundrum of energy supply and demand suitable in rural areas.As result of the high volatility of solar energy,the operation strategy based on fixed parameters may not ensure the optimal operation of solar distributed energy system.In this study,the dynamic operation strategy of allocating the remaining electricity of photovoltaic cells according to the variable proportion was set up under the grid connection and off-grid solar distributed energy system forms.An optimization model for the solar distributed energy system based on dynamic operation strategy was established with the objective function of equal annual net cost,so as to build up the solar energy usage potency of the system.Specific work contents are as follows:Firstly,the solar distributed energy system is designed.Analyze the system operation traits and set up the system operation strategy.Establish a solar distributed energy system with solar energy as the main energy source.According to the different economic conditions in rural areas,the grid connection and off-grid system forms are determined to meet the thermal and electricity needs of buildings.The conventional control strategy and operation characteristics of the system are analyzed.On this basis,a dynamic operation strategy with variable energy distribution is established.And set up two energy allocation fixed operation strategy for comparison.Secondly,the mathematical model of solar distributed energy system is assured and the typical building thermoelectric load is obtained.The equipment modeling is carried out for the key equipment in the grid-connected and off-grid solar distributed energy system.The export features of the solar collector,solar PV cell,air source heat pump,diesel generator and electric heater,as well as the energy storage characteristics of the heat storage water tank and energy storage battery in the system are analyzed.Energy Plus energy consumption software was used to simulate and obtain the hourly heat load of typical building heating season.Obtain the main electricity consumption rules of typical buildings through investigation.They lay a elements for the optimization design of solar distributed energy system.Finally,an optimization model of the solar distributed energy system is fixed and the consequences are compared and analyzed.Through Matlab programming,taking the minimum net cost of equal annual value as the objective function,genetic algorithm is used to search for optimization.Combined optimization of system design and operation is carried out under dynamic operation strategy and comparative operation strategy.Unlike criteria should be considered when the solar distributed energy system is connected to and off the grid.Time-of-use electricity price and photovoltaic power subsidy should be considered during grid connection.The economic performance of gridconnected solar distributed energy system under three strategies is analyzed.Economic performance of off-grid solar distributed energy system under three strategies at off-grid time separation.The light amount of off-grid system is analyzed.Compared with the traditional energy supply system,the elementary energy saving rate,the CO2 emission reduction rate and the economic cost saving rate are used as the evaluation criteria to analyze the benefits of the grid connected and off-grid solar distributed energy system.The results revealed that:(1)Operating inside the dynamic operation strategy,the economic property of the grid-connected solar distributed energy system is significantly improved when the peaking and valley price diversity of the TOU electricity price is large.Compared with the two control operating strategies,the maximum annual net cost savings of the system can be more than 5%.Energy storage batteries should be set in the optimal capacity configuration of the system to achieve the best economic performance of the system.(2)Operating inside the dynamic operation strategy,the economic performance of the off-grid solar distributed energy system is significantly advanced.The maximum annual net cost savings of the system were more than 8% compared to the two control operating strategies.In addition,the dynamic operation strategy can significantly reduce the gross total of light abandoned during the operation of the system.Compared with the two control operating strategies,the amount of light abandoned can be reduced by up to45%.(3)The solar distributed energy system is superior to the traditional energy supply system in terms of economy,energy efficiency and environmental benefits.The usage of solar distributed energy system in northwestern rural areas with abundant solar energy resources can really resolve the conflict between the increasing demand for regional energy and the narrow supply of energy.The energy supply of solar distributed energy system fluctuates strongly because of energy conjoining and solar energy.The operation strategy with fixed and fixed parameters of energy allocation cannot make the system run optimally,and the dynamic operation strategy is positively inevitable.The efficacy of the optimization method ground on dynamic operation strategy was verified in the particular case of this study.This approach can regulate the operating policy parameters in real time according to the supply and demand of the system.Thus,it provides some reference for the design and operation optimization of the solar energy system.