Abstract: The complete set of heating and power generation equipment composed of steam turbines and boilers, generators and the ancillary equipment is mostly used for group heating or self-supply heating and power stations in oil refining, chemical, light textile, paper making and other industries. It can provide power for enterprises and improve the economic efficiency of the heating systems. Taking the No.1 turbine-generator of the self-supply heating and power station of one domestic mega refining and chemical enterprise as an example, this paper introduced the revamping scheme of this unit. By redesigning the flow-through section of the original body structure of the extraction condenser and converting the extraction condenser unit into a backpressure unit, the economic loss caused by the long-term inefficient operation of the low-pressure section of the turbine under extraction condition can be avoided and the loss of the cooling source can be eliminated completely. After the revamp of the turbine, the consumption of the comprehensive standard coal of the CHP (Cogeneration, combined heat and power) was reduced to below 150 g/(kWh), which shows significant economic benefits.

Key words: dry gas seal, C-ring, dew point