Extracting, condensing and backpressure system for steam turbine and adjusting method of system

Abstract

The invention relates to a steam turbine pumping and condensing system and an adjustment method thereof. The steam turbine pumping and condensing system includes a steam turbine medium-pressure cylinder, a steam turbine low-pressure cylinder, a condenser and a heat supply system. The steam turbine medium-pressure cylinder and the steam turbine low-pressure cylinder are coaxial. connection, the exhaust steam of the medium-pressure cylinder of the steam turbine is connected with the low-pressure cylinder of the steam turbine through a communication pipe, and the first valve is installed on the communication pipe, and the heating extraction steam of the heating system comes from the exhaust steam of the medium-pressure cylinder of the steam turbine; the medium-pressure cylinder of the steam turbine is connected with the first A heat supply system is also connected between the valves through a heat supply and extraction pipe, and a second valve is arranged on the heat supply and extraction pipe; the condenser is connected with the low-pressure cylinder of the steam turbine; Function. The system can realize the switching operation of the steam turbine among the pure condensing working condition, steam extraction working condition and back pressure working condition without replacing the steam turbine rotor or blades.

Description

technical field [0001] The invention belongs to the technical field of cogeneration of heat and power, and in particular relates to a steam turbine pumping and condensing system and an adjusting method, and is especially suitable for thermal power plants for heat supply. Background technique [0002] At present, my country's policies are gradually emphasizing the promotion of new energy sources and reducing the proportion of thermal power units. For thermal power plants, the exhaust steam of the steam turbine is usually discharged directly through air cooling or water cooling, which causes a huge loss at the cold end. For example, the energy utilization rate of a 300MW subcritical pure condensing unit is about 38%, of which the loss at the cold end accounts for about 45%. After using steam extraction for heating, the energy utilization rate of the unit increases to 60%, but there is still 20% of condensing low-temperature waste heat This part of the heat is difficult to use...

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Problems solved by technology

[0003] Based on the above situation, the present invention overcomes the problems of large changes to the steam turbine body and large investment in the prior art, and proposes a steam turbine condensate pumping system with reasonable design, reliable performance, and the recovery and utilization of all waste heat from exhaust steam of the unit. and its adjustment method

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