The structure of cool

heat

and electricity co-generation system has been presented.By using the thermodynamic theory

the unit price of product cost in said co-generation system under rated working condition has been analysed

the unit price of generation cost and refrigeration cost under different unit price of natural gas cost and different recovery rate of residual heat in exhaust gas under different operating conditions of the micro gas turbine being calculated.Results of calcualtion show that the unit price of generation cost decreases as the recovery rate of residual heat in flue gas(ηy) increases;the increase of unit price for natural gas cost may increase the unti price of generation cost;enhancement of has effects upon decreasing unit price of the generation cost;the unit price of refrigeration cost increases as the unit price of natural gas cost increases;in the event of ηy70%

the influence upon unit price of refrigeration cost will be decreased.