Research On Energy Matching Characteristics Of Small Distributed Combined Cooling Heating And Power System

The distributed combined cooling heating and power system is a new-type energy utilization method which is energy-saving,environment-friendly and increasing the power supply.The system widely used in the field of foreign energy utilization.In recent years,with the increasing of China’s building area the demand for cooling and heating power is large and stable.It also promotes the development of the distributed combined cooling heating and power system in China.The small distributed combined cooling heating and power system has much stronger adaptability,higher safety factor and more flexible arrangement than others.That’s why it is wide application prospect.It studies the operation parameters and energy conversation characteristics of small-scale distributed combined cooling heating and power system.And further optimization measures are proposed to improve energy efficiency.It is of great significance to expand the application of distributed combined cooling heating and power system.The main research contents and corresponding results of this article are as follows:(1)With 10 kW internal combustion engine as power machine,design a small distributed combined cooling heating and power system which mainly including the following parts: The power subsystem produces the residual heat while the electrical energy is output.The refrigeration subsystem provides cold capacity to meet the user’s cooling load demand.The waste heat recovery subsystem is designed to recover the waste heat of the flue gas heat exchanger by improving the cooling water residual heat in the closed water cooling system of the internal combustion engine.the cold,heat and electric load subsystems are used to simulate the user load demand.Finally the combined cooling heating and power is completed.The hydraulic calculation of the system pipeline determines the size of the pipeline and the circulating pump to complete the design of the small-scale distributed combined cooling heating and power system.(2)Relying on the 10 KW small-scale distributed combined cooling heating and power system.It carries out experiments on various operating conditions under different load rates of internal combustion engines,such as cogeneration,cold power supply,and cold and hot electricity.The main operation parameters are analyzed in the following points: the change characteristics of the basic parameters such as fuel consumption,exhaust temperature,water tank temperature and other basic parameters are changed with the output power,and the change characteristics of the output residual heat and thermal power ratio of the internal combustion engine;The influence of ambient temperature and outlet water temperature on the performance parameters of refrigerating machine;The matching conversion characteristics between the maximum cooling capacity,maximum heating capacity and the output energy in different working conditions can be obtained.In order to optimize the operation of the system,the influence of the high and low heat value on the energy utilization and the influence of cooling water temperature on the power efficiency of the internal combustion engine are further analyzed.The experimental results show that the fuel consumption,exhaust temperature,residual heat and thermal power ratio of the internal combustion engine are vary greatly,and the temperature of the water tank and the proportion of cooling water residual heat are basically stable.Ambient temperature and outlet water temperature have great influence on the performance of refrigerator.The results of energy utilization were different with different calorific values.Improving the cooling water temperature of the internal combustion engine can effectively improve the efficiency of the internal combustion engine.(3)In order to further improve the primary energy efficiency of the omnipotent energy supply system,a DCCHP engine exhaust smoke low temperature residual heat coupled air source heat pump system is proposed to achieve deep recovery of waste heat from the exhaust.Using the Aspen Plus chemical process simulation software,the low temperature flue gas is used as the low temperature heat source of the air source heat pump,the coupling system is constructed,and the key parts and evaluation indexes of the system are analyzed in detail.At the same time,the coupling system is simulated by using 10 kW small distributed multi-energy joint system.The results show that the system can significantly improve the energy utilization rate and COP of heat pump,and solve the problems of the evaporator frosting in the winter heat pump unit in the cold region and the poor operating performance in the low temperature environment.