| In the background of the energy shortage in today’s world, the energy saving has become the main topics of the society, but energy saving cannot be at the expense of the user’s comfort and economic development, therefore, improving energy utilization efficiency as the important means of energy saving has been closely watched. The distributed cold heat and power tri-generation systems can provide cold, heat, power, and other terminal energy, in line with the scientific principles of energy using of "temperature counterpart, cascade utilization", it realize cascade and effective utilization of energy, and improve the energy utilization. And the water source heat pump system by entering a small amount of high-grade energy to transfer the low level energy to high level energy, it is a renewable energy technology that supported by the state. Aiming at the composite cogeneration system composed of the cold heat and power tri-generation system and the river water source heat pump system, this article through building the mathematical model and programming simulation, to compare with the regular supply system, and then analysis and evaluation of the composite cogeneration system.First of all, the design of the cogeneration system is closely connected with the load of cooling and heating in the client. This paper using Ds ST to simulate the load, according to the public building energy efficiency standards in China, modeling and simulation the case project for cold and hot load. The complex consists of office, commercial, hotels, and financial, such as buildings, through software simulation to get the all-year hourly cold and hot load of all kinds of building function, In addition, the use of load when the month fell to the share proportion method to simulate the complex living hot water load.Second, the part load performance model of the system is established, the main equipment including internal combustion engines, gas hot water operated absorption refrigeration units, river water source heat pump units and distribution system of variable flow operation. Analysis the model and we can find that the internal combustion engine exhaust flue gas increases with the rising of temperature as the unit load rate, and can reach 430 ℃, and the flue gas flow basically remain unchanged, the internal combustion engine cooling water system of closed cycle, its flow and heat change is very small, the power generation efficiency of internal combustion engine as the unit load rate increases, when the unit load rate is lower than 50%, the efficiency of generating units as the load rate reduce, fell sharply, generating units and efficient range in 50% to 100%.Hot water operated gas hot water operated absorption flue gas absorption refrigeration unit thermal coefficient is affected by cooling water temperature and the load rate, the higher the cooling water temperature refrigeration coefficient is lower. Distribution system is mainly divided into chilled water systems, cooling water system and living hot water system, the energy consumption of variable flow model is set up respectively.Finally, according to the variable working condition performance model, combined with cold and hot load simulated, calculates the annual compound installations, annual power generation system, cooling, heating, gas consumption and power consumption. Designing the regular supply system according to the case project, and calculate the energy hourly consumption of the all year. Than analysis of the variable condition of compound installations, system performance, and comparative analysis of composite installations, systems and conventional energy supply system, including the primary energy consume, Exergy efficiency and the primary energy saving rate.In a word, by establishing the mathematical model and the thorough analysis, this paper put forward a optimization design method for the composite cogeneration system, provide a reference to the studying of the actual operation performance of the composite cogeneration system. |
PDF Full Text Request