Study Of Combined Cooling Heating And Power System Based On Biomass Gasification

The rapid development of society and economy lead to quick energy increase and larger energy consumption. The large-scale utilization of fossil energy lead to energy shortage and environmental pollution. Consequently, the reasonable exploitation and utilization of renewable energy is urgent. This paper proposed and studied a combined cooling heating, and power(CCHP) system based on biomass gasification to provide some references for rational use of biomass energy in China.Based on the theory of energy cascade utilization, a CCHP system intergrated with biomass gasification is proposed. Heat pipe heat exchanger(HPHE) is integrated to the CCHP system to recovery the waste heat of the product gas from gasifier. The recovered waste heat is integrated with the waste heat from the exhaust gas after electricity generation to improve the efficiency. The system configuration, equipment selection and energy utilization and so on are also analyzed.Then, the different operation strategies of the CCHP system are presented, moreover, the energy and exergy flows are analyzed according to the first and the second laws of thermodynamics. A hotel in Beijing being an example demonstrates the analyses. The primary energy rate and exergy efficiency in different operation strategies are obtained. Furthermore, the distributions of energy and exergy losses of all equipment in the CCHP system are obtained. The performances including annual biomass consumptions, excess product outputs, primary energy rate and exergy efficiency are compared between the CCHP systems with and without HPHE.Finally, life cycle assessment models including biomass planting, collection-storage-transportation, power plant construction and operation, demolition and recovery are constructed. The life cycle environmental impact, energy consumption and cost are evaluated, and the cost, global warming potential and energy consumption changed with CCHP capacity are discussed.