Fuel gas-steam combined cycle heat power plant

Abstract

The invention discloses a fuel gas-steam combined cycle heat power plant, which comprises a gas turbine (1), a boiler (2), a steam turbine (3) and a heating network heat exchanger (4), wherein the boiler (2) is provided with an exhaust passage (7), a heat exchange surface (6) is arranged inside the exhaust passage (7), the exhaust passage (7) can be arranged horizontally, vertically or aslant, exhaust of the gas turbine (1) pass through the exhaust passage (7), the boiler (2) is connected with the steam turbine (3) as well as the heating network heat exchanger (4), the boiler supplies steam for the steam turbine (3) or the heating network heat exchanger (4); and a temperature/pressure reducing device (5) is arranged on the pipelines (a, b and c) connected with the boiler (2) and the heating network heat exchanger (4). By the fuel gas-steam combined cycle heat power plant, heat energy carried by steam is reserved to the largest extent, thereby being capable of better satisfying the demand of heat power plant requiring higher heating heat load in winter.

Description

technical field [0001] The invention relates to a combined cycle power plant, in particular to a gas-steam combined cycle thermal power plant with heating function. Background technique [0002] Such as figure 2 As shown, the combined cycle power plant is equipped with a gas turbine, and also includes a boiler to recover the heat energy in the gas turbine exhaust, convert water into high-temperature and high-pressure steam, and send it to the steam turbine to do work. [0003] In order to obtain heat supply capacity, the conventional solution is to extract the steam that has done work from the steam turbine, and then send it to the heat network heat exchanger to heat the water in the heat network. It must be pointed out that since the steam is extracted after doing work in the steam turbine, part of the heat energy has been converted into electrical energy. For thermal power plants with high requirements on power supply load, this solution is suitable and economical, becaus...

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Problems solved by technology

[0004] The hot network water needed by users for heating only needs to be heated to about 110-150°C, and more commonly 125-135°C. Therefore, the heat network heat exchanger can be made of relatively cheap carbon steel, which requires The steam sent to the heat network heat exchanger to heat the water in the heat network cannot have too high pressure and temperature. In the conventional scheme, the process of reducing the temperature and pressure of the steam is completed in the steam turbine, and part of the heat energy carried by the steam is converted into kinetic energy, and then Converted into electric energy, the rest can be absorbed by the heat network water in the heat network heat exchanger. Therefore, a part of the heat absorbed by the boiler is always converted into electric energy, and cannot be fully supplied to users who need heating.

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