High-flow, low-parameter and high-backpressure expansion power energy-saving system

Abstract

The invention discloses an energy-saving device of a thermal power station, particularly discloses a high-flow, low-parameter and high-backpressure expansion power energy-saving system, comprising a turbine intermediate pressure cylinder and a heat supply backwater heater, which are connected by pipelines, the heat supply backwater heater is connected with a heat supply backwater main pipe and a heat supply backwater heater drain pipe, and the heat supply backwater heater drain pipe is connected with a turbine back-heat heating system, the high-flow, low-parameter and high-backpressure expansion power energy-saving system is characterized in that the pipeline between the turbine intermediate pressure cylinder and the heat supply backwater heater is provided with an expansion power machine. The high-flow, low-parameter and high-backpressure expansion power energy-saving system maximally reduces heat transfer loss between steam and heat supply hot water without influencing heat supply requirement, and converts part of energy in heat supply steam extraction process into high-quality power for output, so that energy is saved. The power output by the expansion power machine can drive generators or other power machines.

Description

(1) Technical field [0001] The invention relates to an energy-saving device of a thermal power plant, in particular to a large-flow, low-parameter, high-backpressure expansion power energy-saving system. (2) Background technology [0002] At present, the condensate back pressure of the 300MW generator set in the power plant is generally 0.0039~0.0054MPa. Obviously, the back pressure heating cannot meet the heating requirements, so the steam extraction must be used for heating. When extracting steam for heating, due to the limitation of the structure of the steam turbine, the exhaust pressure of the medium-pressure cylinder extracted by some units is about 0.4MPa. The external heating supply water temperature is generally between 90-110 degrees, and the return water temperature is 60-70 degrees. According to this calculation, steam with a pressure of 0.1-0.15 MPa can meet the requirements. Therefore, there is a large energy loss in directly exchanging heat with hot water for...

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Problems solved by technology

Therefore, there will be a large energy loss if the heating extraction steam - the exhaust steam of the medium pressure cylinder is directly exchanged with the heating hot water.

For pure back pressure heating units, although it can effectively solve the problem of energy loss of steam and heating hot water, the heat consumption of power generation will greatly increase during the non-heating period, which cannot effectively save energy

How to effectively solve the energy loss problem of the 300MW generator set in relation to steam extraction for heating, there is currently no effective solution for the working condition of low extraction parameters (extraction pressure below 0.5MPa)

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