Research On Gas Turbine Based Distributed CCHP System In Southern China

Distributed Combined cooling, heating and power (CCHP) technology not only has the advantage of higher energy efficiency but also has great significance in energy saving, emission reduction, power supply safety and emergency ability improvement as well as peak load regulation. With the rapid development of economy and society, southern China is suffering from the problems of great energy consumption and large peak-valley difference. Distributed CCHP technology can provide technical support and solutions to these problems. Due to the characteristics of high temperature and humidity in southern China, Distributed CCHP system can only operate in cooling season and has different configuration rule and characteristics under specific energy price and significant influence of ambient temperature on gas turbine performance. Focusing on the problems above, this thesis has studied the prospect of efficient distributed CCHP system based on gas turbine in southern China on the basis of system optimal configuration technology proposed.Firstly, the models of distributed CCHP system and major equipments are built in consideration of output restrictions as well as the temperature and part load influence on gas turbine performance. An optimal configuration method of distributed CCHP system with storage is proposed which can solve the difficulties in discrete optimization of equipment capabilities and numbers.Then according to the characteristics of climate and energy prices in southern China, the applicability of distributed CCHP system used in four typical urban buildings (office, market, hospital and hotel) with micro-turbines and small gas turbines as the prime movers is discussed. The effect of liquid desiccant air conditioning on system energy saving and economic properties in southern China is also analyzed. Furthermore, various operational strategies such as economic optimum, electricity determined by cooling load and grid interconnection with electricity selling, as well as energy prices and their effect on distributed CCHP system performance and economy are analyzed.The results indicate that except office building, micro-turbine and small gas turbine CCHP system have equivalent economic performance and both have better economy, energy saving, emission reduction and peak load regulation performance than that of divided energy supply mode. Liquid desiccant air conditioning is suitable for application and promotion in southern China. But reasonable energy price is necessary in order to further promote comprehensive competitiveness of distributed CCHP in southern China. The validity and effectiveness of the proposed system models and the method are also verified.The work and conclusions of this thesis can provide valuable references for breakthrough point selection, development potential and comprehensive benefit evaluation for CCHP in southern China.