Optimization Research On Combined Cooling,heating And Power System Based On Control Equipment Operation

Considering the variability of the building loads,the energy flow of the combined cooling,heating and power system cannot match the load well,resulting in low equipment use efficiency.Therefore,it is proposed to couple the combined cooling,heating and power system,solar energy system and ground source heat pump to make better use of renewable energy.The multi-energy flow conversion is utilized to realize the coordinated operation of energy system.A hotel building in Beijing is considered as an example for analysis.The primary energy consumption,annual total cost,and carbon dioxide emission are considered as the optimization goals.The black hole algorithm is used to optimize the solution.The main research contents are shown as follows:(1)The concept of equipment startup threshold is proposed to control equipment operation and optimize the efficiency of operating equipment.The equipment shares the building load proportionally in the traditional system.When the building load is low,the load rate of the equipment will also decrease,which will affect the operation efficiency of the equipment.When the equipment load rate is lower than the startup threshold,the equipment will stop running.This part of the load is transferred to another equipment.The operating efficiency of both equipment has been improved.The startup threshold is very good to limit the low-load operation state of the equipment.The system applied the startup threshold of the equipment is compared and analyzed with the traditional system.(2)The startup threshold is applied to ground source heat pump.The startup threshold is setting as the optimization variable to solve.The startup threshold model is compared and analyzed with the traditional system.The results show that: energy,economy and environment indicators of the ground source heat pump startup threshold model are obviously much better than the traditional system model.In terms of energy indicators,the startup threshold model has an energy saving rate of 10.30% compared to the traditional model;in terms of economic indicators,the startup threshold model has an economical savings rate of 5.70% compared to the traditional model;in terms of environmental indicators,the startup threshold model achieves 9.40% reduction in carbon dioxide emissions compared to the traditional model.(3)Six models are established by applying startup thresholds on different devices to explore the performance of different models.The models are analyzed under two operating strategies including following electricity load and following heating load.The results show that: the multi-device startup threshold model has the best comprehensive performance under following electricity load.