The Research Of The Combined Cycle System Based On Complementary Multiple Renewable Energy

Since the20th century, because of the over-exploitation on the coal, oil and other fossil fuels people created a wealth of material and caused a large amount of wasted resources and pollution emissions at the same time. In recent years, the distributed energy system as one of the important directions of energy development attracted widespread attention. In this context, this paper designed a combined cycle system with complementary multiple renewable energy The system can achieve the high efficiency and high quality utilization of the low-grade energy and improve the energy efficiency and reduce the emission of harmful substances. It is very important for satisfying energy needs and easing the contradiction between supply and demand of energy. The research has drew the following conclusions:(1) The paper designed a combined cycle system with complementary multiple renewable energy and analyzed the thermodynamic performance of the system by Aspen Plus V7.2. In order to maintain the normal operation of the micro-gas turbine, the system needs biogas420m3/d. So the fermentation tank size should be210m3. And to ensure the normal process in fermentation, the system needs solar heat absorption capacity of148.8kW at least based on the conservation of energy. This is equivalent to125sets of the solar collector with30tubes. The methane content in the purified primiparous biogas can reach98%. The biogas as the fuel can promote the micro-gas turbine output30kW power. Then the exhaust gas can be used to drive the ORC unit and combined output40kW power. The EUR of the system can reach32.83%. Compared with single micro-gas turbine the EUR increased by31.83%. Compared with separated system the EUR increased by35.94%. And the ESR of the system can reach26.43%.(2) Based on the performance simulation of the system, The paper analyzed the influence of the key parameters on the system performance such as the ambient temperature, the methane content and the gasturbine inlet temperature.The change of ambient temperature will directly affect the power consumption of the compressor, will affect the output and efficiency of the system. The change of methane content will affect biogas combustion process in the combustion chamber. The change of gasturbine inlet temperature can cause the change of the turbine work process, will affect the performance of the combined cycle system.(3) The paper analyzed the system economics using static analysis approach and dynamic analysis approach, The results showed that the static payback period is6.94years, and the dynamic payback period is8.77years. but also analyzed the influence factors of the economy. The results showed that the factors can impact the annual savings rate and the investmen payback period of the system in different aspects such as the gasturbine sets, the gas price and the electricity price. Compared to the power grid, the static annual money saving rate is37.87%and the dynamic saving rate is26.35%. At the same time, the paper analyzed the influence factors of the economy. The results showed that the factors can impact the annual savings rate and the investmen payback period of the system in different aspects such as the gasturbine sets, the gas price and the electricity price.The innovation and the significance:Through the combination of the solar biogas fermentation link, biogas power generation link and ORC cogeneration link, This paper constructed the original combined cycle system with complementary multiple renewable energy based on the energy supply principle and analyzed the thermodynamic property of the combined cycle system.Based on the energy supply principle about the contra-aperture of temperature and the energy cascade utilization this paper constructed the original combined cycle system with complementary multiple renewable energy. The biogas that from solar energy as the system fuel replaced the traditional fossil fuels can reduced the emissions of the harmful gases. And the system has good capability of the energy conservation and emissions reduction and the huge social economic benefits. By the way, this research has important academic reference value for the further research of the distributed energy system and important significance to promote the sustainable development about the energy, environment and human society.