Research On Integration And Performance Of Park Level Distributed Energy System With Multiple Renewable Energy Complementary

With the continuous progress and development of society,the problems of environmental pollution,energy shortage and climate change are becoming more and more prominent.Especially at present,a large number of various wastes have been produced in human lifestyles.If the waste can be treated as resources and energy,and the recycling of waste can be realized,it can greatly promote the scientific adjustment and reconstruction of energy consumption structure and utilization mode.Take the fruit and vegetable waste resource treatment and utilization park located in Lanzhou as the background,this paper constructs a distributed energy system with complementary multiple renewable energy sources,studies the operation status of the system when it meets the annual energy demand of the park,compares and analyzes the performance differences between the system and the original system and distribution system,and reveals the energy economy of the system,It provides some ideas and references for the application of distributed energy system in waste resource recycling and transformation.The main research contents and conclusions are as follows:（1）Combine with the field research and the data provided by the park,analyze the material balance,available renewable resources,energy consumption and the problems existing in the original energy supply system.The park handles 2000t and 100t of waste per day under full load and low load conditions respectively.There are great differences in the process flow and the available amount of renewable resources under the two conditions,resulting in completely different energy consumption conditions.The original energy supply system of the park is composed of biogas internal combustion generator and oil/gas dual-purpose boiler.Although the original system realizes cogeneration by consuming the self-produced biogas in the park,it also needs to supplement external power and diesel resources while wasting a lot of low-grade heat energy,which has great room for improvement.（2）Construct the distributed energy system,which takes biomass energy and solar energy as the main input energy,organically combines biogas internal combustion generator set,photovoltaic photothermal integration device,dual source heat pump and sewage source heat pump.Establish the mathematical model of each subsystem,establish the full working condition simulation model of the system in Matlab/Simulink,and verify the model of the main equipment according to the relevant literature and the data provided by the equipment manufacturer.（3）Combine with the established full working condition simulation model of the system,the capacity and operation mode of the main equipment of the system are determined,the daily operation performance of the system under the two working conditions is analyzed in detail,and the energy flow diagram of the system under full load condition and the whole year is drawn.The system adopts the heat following operation mode to give priority to ensuring the normal operation of hydrolysis process and anaerobic process in the park.Under full load condition,the amount of fruit and vegetable waste treatment is large,and all energy consuming equipment operate at high load.Compare with the original system,the new system saves 12.04%of biogas consumption,does not need to input fossil energy,and has surplus electricity to connect to the Internet;Under low load conditions,all energy consuming equipment operates at low load,only the photovoltaic photothermal integration device and heat pump unit operate.Compare with the original system,the new system saves 57.52%of fossil energy input during this period.（4）Take the traditional energy supply system and the original system as a reference,the energy economy and environmental protection benefits of the new system are revealed.The results show that the annual average comprehensive energy utilization rate of the new system is 82.71%,and the annual average energy saving rate is 32.23%.Compared with the original system,the energy input can be reduced by 24.85%,and the energy saving effect is remarkable.The static investment payback period of the new system is 3.39 years.Compared with the original system and the traditional distribution system,the annual cost savings of the new system are 11.67%and 25%respectively,which is economically feasible.Compared with the original system and sub supply system,the annual CO₂ emission factor of the new system is218.14g/kw·h,and the annual CO₂ carbon emission reduction rates are 24.26%and 34.74%respectively,which has great potential for CO₂ emission reduction.After combined with the waste treatment system,the annual consumption of fruit and vegetable waste is 386100t,the sales of biogas is 1056878.14m³,the production of biogas fertilizer is 50655.2t,and the sales of electricity is 2176294kw·h.external power input is only required under low load conditions.