Research On Optimal Allocation Of Natural Gas CCHP Systems

In recent years, as the extremely rapid growth of energy consumption in ourcountry, the resulting environmental problems are increasingly serious, which hasbecome an important bottleneck of the sustainable development of economy in ourcountry. Adjusting the energy structure, improving energy effici ency, reducingenergy consumption, especially to reduce the energy consumption of HVAC andsanitary hot water have become China’s energy strategy priorities.CCHP(Combined Cooling Heating and Power)system is established on the basisof energy cascade utilization,and it’s a multi-generation energy system of integratingthe cooling,heating and power generation. Its collection of high-tech and equipmentfor the integration and the output energy cascade utilization, not only greatly improvethe efficiency of energy utilization and reduce the investment and operation cost, butalso improve the security of energy systems and protect the environment.In this paper, the conception, characteristics, composition and classification ofnatural gas CCHP systems are introduced,and the common typical process of CCHPsystem are summed up and their respective works are illustrated. In the thesis, variouscollocation principle of CCHP system is illuminated and taking a hospital building ofChangsha city as the research object. First using energy consumption simulationsoftware EnerygPlus and DesignBuilder to simulate the annual energy consumption ofbuildings, geting all-year hourly cold, heat, electricity load data of the building. ThenSelecting respectively two different system configurations based on the principle ofelectricity determined by heat and heat determined by electricity to establisheconomic optimization model. The objective function is set up according to the leastannual cost, the most annual income. Finally, making the optimization calculation tofour schemes by optimization algorithm. Through optimization, the optimized systemconfiguration scheme are confirmed and the best quantity and capability ofgas-burned machine, purchasing electricity from net, cooling and heatingcomplemented by gas burned are also confirmed. The operation strategy of winterand summer and transition seasons are determined on the basis of the systemconfiguration scheme by optimization. Meanwhile, comparison between optimizedscheme and the separate heat, cool and electrical systems, among this, it can be seenthat the CCHP system configuration has energy saving and the two gas engine schemes based on the principle of heat determined by electricity have advantage forthe hospital building CCHP system. This method provides effective methods andreference for other building to select the best configuration scheme.