Air-cooled steam turbine high back pressure heat supply cogeneration method

Abstract

The invention discloses a high backpressure combined heat supply and power generation method for an air-cooling steam turbine, belongs to combined heat and power generation methods, and aims at constructing, expanding and reconstructing a thermal power plant. The method involves a condensation water treating system, and a steam turbine connected with a boiler and a generator; a steam turbine unit comprises at least one air-cooling steam turbine under the backpressure range of 6 to 60kpa; in the heating season, the backpressure range of the air-cooling steam turbine is 36 to 50kPa; in other seasons, the backpressure range of the air-cooling steam turbine is 6 to 10kPa; a low pressure cylinder of the air-cooling steam turbine is connected with a condenser; the condenser is connected with an urban heat network and a condensed water fine treating device. With the adoption of the method, the power generation quantity and the heat supply area can be greatly improved; the cold end loss is zero; the coal consumption in power generation can be reduced; the energy is saved; the efficiency is high; the economy and practicability are achieved.

Description

technical field [0001] The invention relates to a cogeneration method of heat and electricity, which is used for new construction, expansion and transformation of thermal power plants. Background technique [0002] Combined heat and power generation refers to the production mode in which the power plant not only produces electric energy, but also supplies heat to users, that is, the process of producing electricity and heat energy at the same time, which saves fuel compared with the way of producing electricity and heat energy separately. In the combined heat and power project, the steam turbine uses the boiler steam to do work, thereby driving the generator to generate electricity; at the same time, the steam is extracted from the cylinder of the steam turbine, and the circulating water of the heating network is heated by the heating network heater, and then supplied to the urban heating network. Commonly used steam turbines are divided into condensing steam turbines, heati...

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Problems solved by technology

The process of using the extraction condensing unit has the following disadvantages: First, the quality of the steam extracted from the medium-pressure cylinder is high, and it still has the ability to work, but it is used to extract steam for heating, and the energy utilization rate is low, and the power generation output of the unit decreases, 350MW The unit can only generate 266MW when heating; secondly, due to the requirement of the minimum flow rate of the low-pressure cylinder of the steam turbine, 148t / h of exhaust steam must be condensed in the condenser, and the heat of these exhaust steam is lost from the cooling tower, resulting in The loss of the cold end considerably reduces the heating area by about 25%

Drainage should be discharged in time, otherwise it will not only absorb the heat of steam in the pipe, affect the flow of steam, but also cause serious water hammer phenomenon and cause serious consequences

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