The energy consumption of cogeneration unit is greatly increased due to industrial steam supply

which leads to the decline of thermal economy of power plant. In this study

a 310 MW unit is selected as the research object. Method of software simulation and experiment are used. The EBSILON software is used to model and simulate the operating conditions of the unit under two steam extraction sources

three extraction pressures

and different electrical loads respectively. The exergy loss and energy consumption critical characteristics of industrial steam supply are analyzed. The results show that

the heat consumption of the unit is different under the steam source of cold reheating and hot reheating industrial steam supply. There is a critical characteristic curve of energy consumption for industrial steam supply. This curve is of great significance to the economic operation of the unit.Only when the unit operates on the right area of the curve

the unit heat consumption of the industrial steam supply condition is less than that of the pure condensing condition

and the industrial steam supply is beneficial to reduce the energy consumption level and improve the thermal economy of the unit. When the unit operates on the left area of the curve

the heat consumption under industrial steam supply condition is greater than that of pure condensation condition. It is suggested that the industrial steam supply flow and steam source parameters between units should be reasonably planned during the transformation of industrial steam supply in thermal power plant.