Optimization Of Multi-Energy Complementary Low Carbon Energy Supply System For Container Houses

Container houses are becoming increasingly common in China,with various advantages such as spaciousness,good sealing,ruggedness,and corrosion resistance.Their uses include warehouses,offices,temporary rest rooms,activity exhibition halls,dormitories,etc.They have also been widely used in the Winter Olympics.This type of house is not only cost-effective,but also convenient to build,energy-saving and environmentally friendly,known as the "new green building".Solar energy is a universal,harmless,large and long-lasting renewable energy source.Temporary buildings such as containers are often used in outdoor suburbs,with an open environment and unobstructed buildings.They also have a large roof area,which is very conducive to the application of solar energy systems.Considering that indoor temperature cannot guarantee normal human activity under extreme weather conditions,air source heat pumps can be used in conjunction with solar energy to ensure that the indoor temperature is at an appropriate level at any time,thereby ensuring human comfort.Based on this,this paper designs a multi energy coordinated heating system,and studies the system control strategy by combining heat storage and power storage technology,so that the system can operate continuously under the premise of low power consumption.The main work and conclusions are as follows:Firstly,the heating system was modeled through Simulink/MATLAB.The model includes eight models,including photovoltaic solar thermal module,heat storage tank,plate heat exchanger,air heat exchanger,compressor,expansion valve,radiant capillary and room,which provide the basis for the subsequent coupling operation of various components.At the same time,the control strategy was designed,including indoor temperature control,heat collection cycle control and heat source switching control.Two schemes were designed for each type of control strategy,Indoor temperature control is divided into fixed temperature control and fixed temperature interval control;The heat collection cycle control is divided into fixed solar radiant intensity g control and fixed heat collection cycle temperature difference control;The heat source switching control is divided into fixed water tank temperature control and fixed time control,providing a basis for subsequent comparison and optimization.Secondly,by building an experimental platform,the simulation model was validated,including the temperature of the ethylene glycol solution at the outlet of the photovoltaic panel,the temperature of the ethylene glycol solution in the water tank,the temperature of the ethylene glycol solution at the outlet of the plate heat exchanger,the temperature of the glass plate of the photovoltaic photothermal module,the refrigerant condensation and evaporation pressure,the power consumption of the compressor,the temperature of the surrounding structures during room heating and cooling processes,all of which proved the reliability of the model.Then,different control strategies are applied to the simulation heating model.The results show that under typical daily conditions,constant temperature control consumes less power,but starts and stops too frequently,which is not suitable for long-term operation;Controlling the temperature difference of the circulating solution with a fixed collector cycle temperature difference is better than controlling the solar radiation intensity;The constant water tank temperature control can meet the long-term operation of the system,but the power consumption is high.Compared to the constant water tank temperature control,it can ensure higher COP and lower power consumption,but cannot cope with adverse weather.Finally,on the basis of the original control strategy,the heat source switching control and indoor temperature control were optimized.The combination of fixed water tank temperature control and fixed time control not only effectively reduced power consumption,but also ensured the reliability of continuous operation of the system.Moreover,the pre calculation of the system’s heating time was carried out to ensure that the indoor temperature always meets the design requirements of 5 ℃ at night and 18 ℃ during the day.