As a brand new and effective approach to solve biomass resource wastes in China’s rural areas

the multi-kilowatt combined cooling heating and power (CCHP) system has extremely great potential for development. A small CCHP system is designed that is driven by biogas fuelled internal-combustion engine on the transient system simulation program platform considering off-design conditions. Its energy flow and operation mode are described and a model for multi-objective optimization of energy

economic and environmental benefits is developed. The particle swarm optimization algorithm with constraint coefficients is used in calculation to realize the equipment capacity and operation parameter optimization. As an example

a case study is made by simulation using the annual cooling

heating and electrical load of a farmland buildings. The operation performance of the optimized system is analyzed and the difference in performance between the biogas CCHP system and the natural gas CCHP system is shown. The results show that

the optimized CCHP system has effectively achieved energy-saving and carbon dioxide emission reduction compared to conventional separate production system

while the cost of investment can also be recovered within the lifetime of system. On the other hand

comparing to natural gas CCHP system

biogas CCHP system has obvious advantages of resource efficiency and carbon dioxide emission reduction. This work is supported by National High Technology Research and Development Program of China (863 Program) (No. 2014AA052802) and the Funds for International Cooperation and Exchange of the National Natural Science Foundation of China (No. 61320106011).