The thermal system in cogeneration units was divided into three cycles:main condensate cycle

cogeneration extraction cycle and auxiliary steam-water cycle.On this basis

the mass unit based universal calculation equation that was suitable to the main and auxiliary thermodynamic cycles in cogeneration unit thermal systems were established.Moreover

the calculation models of thermoelectric allocation for cogeneration units were constructed.Then

the calorimetric method

the actual enthalpy drop method and the above mass unit based thermo-electric cost allocation algorithm were employed to conduct thermal economic analysis on a 300MW cogeneration unit.The results show that

this mass unit based model has advantages of high accuracy and strong university

which can provide basis for compiling calculation software for thermoelectric allocation in cogeneration units.