Optimization Of Design Parameters And Operating Strategy In Combined Cooling-heating And Power System

Combined cooling heating and power system (CCHP) has been gotten widely attention and promotion with its higher energy useing ratio, less line loss, environment friendly in the situation of energy-saving and emission reduction as well as reform of the energy structure. For different buildings, its energy needs are various. An appropriate combined cooling heating and power system cogeneration and operation strategy should be determined according to the characteristics of the architecture.While there is no actual operational data for the building load, choosing the DeST software in simulation of the cooling load of the selected building, electric load is calculated according to the standards of energy-efficient construction.Thus obtained the building load characteristics within a year. After the discussion of the basic cooling, heating and power cogeneration system configuration characteristics, selecting the micro gas turbine and absorb LiBr absorption refrigeration machine as the building cooling heating and power system configuration according to the building load.Made mechanism models for micro gas turbine and absorption refrigeration machine. Meanwhile choosing capstone C30 unit for the dynamic characteristics study of microturbine in Simulink with modular modeling. Considering the influence in variation of ambient temperature and fuel to system output power, power generation efficiency, temperature and flow of smoke exhaust flow. Getiing dynamic characteristics input and output function of the equipment by basic fitting.After considering the economic, energy saving and environmental protection, the average weight is chosen as the comprehensive evaluation index of the combined cooling heating and power system. While the primary micro gas turbine capacity of 120kw, in the average summer day, winter day and the transition season using operating the system following the thermal load and operating the system following the electric load as operation strategy to simulate the operation. The results showed that in the summer and winter system can maintain full load operation in long time, whereas the transition season less. In the change of micro turbine capacity, the amount of fuel consumption, power consumption and fuel quantity are changed, and the importance of comprehensive evaluation index is reflected.Finally choosing the optimized operation strategy, that is in the transitional season the CCHP system closed and while thermo-electric ratio of system is less than the user’s the electricity is determined according to the thermal, otherwise choosing thermal following electricity. In this operation strategy, taking comprehensive evaluation index as the goal to optimizaing the micro turbine capacity.Results showed that the optimization of micro gas capacity is 90kw. Compared with the separated system, CCHP system shows great advantage in energy saving and environmental protection, but the economy is not high enough. However, the comprehensive evaluation index is still higher than separate system.