RU2261338C1 - Steam power plant with additional steam turbines - Google Patents

Abstract

FIELD: heat supply systems.

SUBSTANCE: proposed steam power plant with additional steam turbines includes power-and-heating plant with open power and heat supply system, gas-turbine plant with recovery boiler and make-up water heating and deaerating unit including at least two additional steam turbines with contact condensers which are placed in softened make up water line. Output of power and heating plant unit is connected by pipeline with input of contact condensers of additional steam turbines of make up water heating and deaerating unit. Output of steam recovery boiler unit of gas-turbine plant unit is connected by steam line with input of additional steam turbines. Input of steam recovery is connected by feed water pipeline with make up water heating and deaerating unit. Output of make up water heating and deaerating unit is connected by make up deaerated water pipeline with system heaters of power and heating plant unit and by feed water pipeline, with input of recovery boiler of gas-turbine plant.

EFFECT: facilitated deaeration and reduced cost of make up water deaeration system of heat supply system increased power and economy of power and heating plant.

2 dwg

Description

A steam-powered plant with additional steam turbines belongs to the field of energy and can be used at combined heat and power plants for the joint production of electric and thermal energy.

A heat and power plant with additional steam turbines is known, containing cogeneration turbines, an open cogeneration system, heating water make-up water treatment plants, including raw water softening plants and make-up vacuum deaerators. The inlet of vacuum deaerators through softened decarbonized water is connected by a pipeline to a water softener, and through heating water it is connected by a pipeline to a direct network water pipeline of an open heating system. [Oliker I.I., Ivanov V.E., Sivko E.P. New water deaeration schemes for thermal power plants with two-stage vacuum deaerators, CCTI journal // Thermal Engineering. 1972, No. 4, p. 44-47.]

Softened and decarbonized, make-up water of the described combined heat and power plant is supplied to vacuum deaerators with a temperature of 30 ° C, which leads to a deterioration of the deaeration process, to an increase in the consumption of heating water for vacuum deaerators and the energy consumption for the station's own needs.

The closest in technical essence is a cogeneration plant with an open cogeneration system, containing cogeneration turbines with double cogeneration steam extraction. The condensers of these turbine units are equipped with built-in and main beams. Built-in bundles of capacitors at the inlet are connected to the pipelines of raw water, and at the outlet they are connected by pipelines with a softening unit, the output of which is connected by a pipeline of softened and decarbonized make-up water to the inlet of the vacuum deaerator. The deaerator inlet is connected by a heating water pipeline to a direct network water pipeline of an open heating system [V.I. Sharapov. Preparation of makeup water for heating systems using vacuum deaerators. - M .: Energoatomizdt, 1996. Fig.8.8., P.137].

In the described heat and power plant with an open heating system, the initial raw water is heated before installing its softening in the built-in bundles of turbine condensers to a temperature of 35-50 ° C, and the heating water for vacuum deaerators is heated in the lower and upper network heaters of heating turbines.

In this installation, there is a need to use vacuum deaerators, the heating water for which is supplied from a direct line of the heating network, which reduces the consumption of network water to heat consumers and the thermal power of the cogeneration plant. In addition, the heating water of vacuum deaerators is throttled in front of them, which leads to an excessive consumption of electricity for its transfer.

The objective of the proposed technical solution is modernization, which allows to simplify and reduce the cost of the deaeration system of make-up water of the heating system, to increase the power and efficiency of this cogeneration plant.

This goal is achieved due to the fact that the steam power plant with additional steam turbines is made of three blocks: a heating unit with an open heating system and a heating steam turbine with heating steam extraction, a condenser with an integrated beam, an electric generator, network heaters, reverse and direct network water pipelines , a pipeline of softened and decarbonized make-up water; an additional unit with at least one energy gas turbine with a steam recovery boiler and an electric generator, and an additional unit for heating and deaerating make-up water, which contains at least two additional steam turbines with electric generators and contact condensers included in the make-up line softened water; the output of the combined heat and power unit with an open heating system is connected by a pipeline to the input of the contact condensers of the additional steam turbines of the heating and deaeration block of the make-up water, the output of the steam recovery boiler of the gas turbine unit is connected by the steam line to the input of the additional steam turbines, and its input is connected by the feed water pipe to the block heating and deaeration of make-up water; the outlet of the feed water heating and deaeration unit is connected by the deaerated make-up water pipeline through the make-up and network pumps to the network heaters of the cogeneration unit with an open heating system, in addition, its outlet is connected by the feed water pipeline through the feed water purification unit and the feed pump, the feed and heating block and deaeration unit water with the input of the waste heat boiler of a gas turbine installation.

The use of at least two additional steam turbines in the modernized heat and power plant equipped with contact condensers and fed with steam generated by a recovery boiler installed behind an additional gas turbine installation allows parallel and sequential heating and vacuum deaeration of the heating system feed water in the condensers of these steam turbines . Due to this, the quality of deaeration of make-up water is improved.

The generation of electricity in the electric generators of these steam turbines operating in condensation mode using the heat of the exhaust steam to heat the make-up water allows us to modernize the cogeneration plant with an open heating system, increase its electric and thermal power, and increase its thermal efficiency.

The use of an additional gas turbine unit equipped with an electric generator and a recovery steam boiler, using part of softened and deaerated make-up water as feed water, can additionally increase the electric power of the combined heat and power plant, while steam generation by the recovery boiler allows it to supply additional steam turbines.

It is possible to carry out a series or parallel connection of contact capacitors in the heated make-up water of the heating network, which makes it possible to increase the efficiency of the cogeneration plant when changing the water flow for the needs of hot water supply to consumers from an open heating system.

Figure 1 shows a block diagram of a steam power plant with additional steam turbines, and figure 2 shows its schematic diagram.

The block diagram of figure 1 consists of three blocks: cogeneration plant with an open heating system 1; gas turbine unit with a waste heat boiler 2; block of heating and deaeration of makeup water 3.

Figure 2 shows a schematic diagram of a steam power plant with additional steam turbines, where the cogeneration unit with an open heating system 1 contains a heating steam turbine 4, a condenser with an integrated beam 5, a softened and decarbonized make-up water pipe 6, lower 7 and upper 8 network heaters, the straight line pipeline of the heating network 9, the return pipeline line of the heating network 10, the make-up pump 11, the network pump 12, the deaerated make-up water pipe 13.

The unit of a gas turbine installation with a waste heat boiler 2 comprises a gas turbine installation with an electric generator 14, a steam waste heat boiler 15, a steam line 16.

The heating and deaeration unit of make-up water 3 contains additional steam turbines 17 and 18 with electric generators, contact condensers 19, condensate pumps 20 and 21, a softened make-up water pipe 22 with shut-off valves, a bypass pipe 23 of deaerated make-up water with shut-off valves, a make-up water collection pipe 24, a feed water pipe 25, a feed water treatment unit 26, a feed water pipe 27 with a feed pump.

Steam-powered installation with additional steam turbines is made as follows.

The built-in bundles of the condenser 5 of the heating steam turbine 4 of block 1 are connected at the inlet to the raw water pipeline, and at the output are connected by the softened and decarbonized make-up water pipe 6 through the softening installation with the contact water feed of contact condensers 19 of the steam turbines 17 and 18 of block 3.

The input of the waste heat boiler 15 located in the exhaust gas duct of the gas turbine unit 14 of unit 2 is connected to the unit 1 by the feed water pipe 25 through the feed water treatment unit 26 and the feed pump 27 of the unit 3. The output of the recovery boiler 15 is connected by the steam line 16 to the inputs of the additional condensation steam turbines 17 and 18 of block 3.

The return pipe of the heating system 10 through the network pump 12, the lower 7 and the top 8 of the network heaters is connected to the pipe of the direct line of the heating system 9 of the heat and power unit with an open heating system 1. The return pipe of the heating system 10 through the make-up pump 11 and the storage tank is connected to the deaerated make-up pipe water 13 block 3.

Contact condensers 19 of steam turbines 17 and 18 are connected by a softened make-up water pipe 22 to shutoff valves and through a softened and decarbonized make-up water pipe 6 with integrated condenser bundles 5 of a heating steam turbine 4 of unit 1. The contact condenser 19 of the steam turbine 17 is connected through a condensate pump 20 one bypass pipeline of deaerated make-up water 23 with shutoff valves with the input of the contact condenser 19 of the steam turbine 18, and the second pipeline through the collection pipe the makeup water supply 24 is connected to the deaerated makeup water pipe 13 of the block 3. The output of the contact condenser 19 of the steam turbine 18 is connected through the condensate pump 21 and through the makeup water collection pipe 24 to the deaerated makeup water 13 of the block 3.

Steam-powered installation with additional steam turbines works as follows.

The steam spent in the cogeneration turbine 4 enters the condenser 5 and in the built-in bundle of this condenser heats up the raw water, which is then fed after softening and decarbonization to the pipeline 6 of softened and decarbonized make-up water.

Pipeline 6 of softened and decarbonized make-up water is supplied with make-up water in condensers 19, where the exhaust steam of additional steam turbines 17 and 18 is supplied, and where condensation occurs. Due to the transfer of heat from condensing steam to feed water, it is heated. Non-condensable gases are removed from the capacitors 19 using their ejector installations. As a result of this, a vacuum deaeration of the make-up water takes place in the capacitors 19. Depending on the operating mode of the open heating system and the flow from it by consumers of various amounts of water for the needs of hot water supply, there is the possibility of parallel or series connection of capacitors 19 for make-up water. When they are switched on in parallel, the shut-off element on the softened make-up water pipe 22 is open, and the shut-off element on the bypass pipe of the deaerated make-up water 23 is closed. When the capacitors 19 are connected sequentially through make-up water, the shut-off element on the softened make-up water pipe 22 is closed, and the shut-off element on the bypass pipe 23 of the deaerated make-up water is open. The deaerated heated make-up water from the condensers 19 by means of condensate pumps 20 and 21 and through the collection pipe 24 of the make-up water enters the pipe 13 of the deaerated make-up water of the unit 3, and through the accumulator tank and the make-up pump 11 is supplied to the return network water pipe 10. A part of the make-up water water through the feed water pipe 25 through the feed water treatment unit 26 and the feed pump 27 is supplied to the input of the recovery boiler 15. Mains water from the return network water pipe 10 by the network pump 12 it is given through the lower 7 and upper 8 network heaters into the direct network water pipeline 9. In the lower 7 and upper 8 network heaters, the network water of the heating system is heated by steam from the heat extraction taps of the heating turbine 4.

An additional gas turbine installation 14 provides a drive for an electric generator and additional power generation. Due to the utilization of the heat of the flue gases of the gas turbine unit 14, steam is generated in the waste heat boiler 15, which is sent via the steam line 16 to the input of additional steam turbines 17 and 18. The steam that has been spent in them is fed to the input of the contact condensers 19 of the steam turbines 17 and 18.

The proposed layout of the steam power plant with an open heating system has advantages both over the known analogues and over the prototype.

At least one energy gas turbine with a steam recovery boiler and at least two condensing steam turbines with electric generators and contact condensers are additionally located therein. There is a possibility of their inclusion in the line of make-up softened water with parallel or sequential passage of make-up water through them. At high flow rates of make-up water, softened water is divided into two streams. Each of the flows is supplied to its own contact capacitor, condenses the exhaust steam, heats up and deaerates. In operating modes with reduced feed water consumption, this technical solution provides for the sequential inclusion of contact capacitors in the softened make-up water line, due to which an additional increase in the temperature of makeup water and its deaeration are provided.

At high flow rates of make-up water, softened water is divided into two streams. Each of the flows is supplied to its own contact capacitor, condenses the exhaust steam, heats up and deaerates. In operating modes with reduced feed water consumption, this technical solution provides for the sequential inclusion of contact capacitors in the softened make-up water line, due to which an additional increase in the temperature of makeup water and its deaeration are provided.

Compared with the known schemes, including the prototype, due to this, the proposed technical solution provides increased electric power and thermal efficiency of the modernized heat and power plant with an open heating system.

Claims (1)

A steam-powered installation with additional steam turbines is made of three blocks: a cogeneration unit with an open heating system and a cogeneration steam turbine with cogeneration steam extraction, a condenser with an integrated beam, an electric generator, network heaters, reverse and direct network water pipelines, a softened and decarbonized make-up water pipeline; an additional unit with at least one energy gas turbine with a steam recovery boiler and an electric generator, and an additional block for heating and deaeration of make-up water, which contains at least two additional steam turbines with electric generators and contact condensers in line make-up softened water; the output of the combined heat and power unit with an open heating system is connected by a pipeline to the input of the contact condensers of the additional steam turbines of the heating and deaeration unit of the make-up water, the output of the steam recovery boiler of the gas turbine unit is connected by the steam line to the input of the additional steam turbines, and its input is connected by the feed water pipe to the heating and deaeration of make-up water; the outlet of the feed water heating and deaeration unit is connected by the deaerated make-up water pipeline through the make-up and network pumps to the network heaters of the cogeneration unit with an open heating system, in addition, its outlet is connected by the feed water pipe through the feed water treatment unit and the feed pump of the feed and water heating and deaeration unit with the input of the waste heat boiler of a gas turbine installation.

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