JP2015175299A - thermal power plant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal power plant in which in a turbine system, when drain generates in steam piping for flowing extraction steam after heat exchange in a desuperheater provided for heating feed water to a feed water heater, backflow of the drain to the desuperheater is prevented, and piping around the desuperheater is optimally arranged.SOLUTION: In the present embodiment, a turbine system is provided which has a feed water heater for heating feed water produced by condensing exhaust steam from a turbine, and a desuperheater for further heating the heated feed water. In the turbine system, the feed water heater which is supplied with the steam after heat exchange with the feed water in the desuperheater, is disposed at a vertical lower portion of the desuperheater, and a water chamber part of the desuperheater is disposed in the same plane with and opposite to the water chamber part of a front stage feed water heater in a water feed system.

Description

In the thermal power plant, as shown in FIG. 1, the exhaust steam that has finished work in the turbine 23 is condensed in the condenser 25 to become water, and the water is supplied to the water supply line as water supply. The feed water is heated by a plurality of feed water heaters 2, 3, 4 and then flows into the boiler 22.

The heat source that heats the feed water in each feed water heater is extracted steam from the turbine 23, and the heater drain 40 that is generated when the extracted steam exchanges heat with the feed water in each feed water heater is the next lower stage feed water heater or It flows into the deaerator.

Since the feed water pipe and the heater drain pipe 40 connected to the feed water heater are connected to the front and rear feed water heaters, the feed water heater is located in the vicinity of the front and rear feed water heaters in order to realize an economical piping route. Often placed.

By the way, instead of using a feed water heater for heating the feed water, a desuperheater (steam desuperheater) may be used. This is because the heat of the extracted steam is supplied to the desuperheater to exchange heat with the feed water, and the steam whose temperature is reduced after the heat exchange is used again for heat exchange with another feed water. Water heating can be performed once.

If it demonstrates in FIG. 1, the extraction steam from the turbine 23 will be supplied to the desuperheater 1, and will perform heat exchange with the feed water from the feed water heater 3 one step before. The extracted steam that has been subjected to heat exchange is supplied to the feed water heater 2 in a plurality of stages in the form of steam that has been reduced in temperature as steam (that is, not drained), and is further used for heat exchange with the feed water. It is drained afterwards.

Here, when the drain is generated in the steam pipe 5 connected to the feed water heater 2 in a plurality of stages from the bleed steam outlet of the desuperheater 1, the cylinder side through which the steam of the desuperheater 1 enters and exits is a drain liquid. Since there is no surface level, some arrangement is required so that the drain does not flow back to the desuper heater 1.

In addition, the connection between the desuperheater extraction system and water supply system is different from that of general water heaters. Therefore, if the desuperheater and the water heater connected to this are not optimally arranged, the extraction pipe and water supply pipe This increases the amount of material, makes piping routing uneconomical and occupies space.

JP 2010-121632 A

The present invention has been made to solve such a problem, and in a turbine system of a thermal power plant, the extracted steam that has been subjected to heat exchange by a desuperheater provided for heating the feed water is caused to flow to the feed water heater. The purpose is to prevent drain from flowing back to the desuperheater when drainage is generated in the steam pipe and to optimally arrange the pipe around the desuperheater.

In order to achieve the above object, the present invention provides a feed water heater for heating feed water generated by condensation of exhaust steam from a turbine, and heat exchange between the heated feed water and extracted steam from the turbine. Furthermore, in a thermal power plant having a desuperheater to be heated, a feed water heater to which steam having been subjected to heat exchange with the feed water at the desuperheater is disposed vertically below the desuperheater, and The water chamber portion of the desuperheater is disposed to face the water chamber portion of the preceding stage water heater in the water supply system in the same plane.

System diagram showing schematic configuration of power plant Configuration layout showing the first embodiment of the present invention Configuration layout showing the second embodiment of the present invention Configuration diagram showing a first example of the third embodiment of the present invention Configuration diagram showing a second example of the third embodiment of the present invention Configuration layout diagram showing a third example of the third embodiment of the present invention

Hereinafter, embodiments of the activation method according to the present invention will be described.

(First embodiment)
As shown in FIG. 1, the feed water 9 from the condenser 25 is heated in the order of the feed water heaters 2, 4, 3, and further heated by the desuperheater 1. For each heating, the extracted steam 32 from the turbine 23 is supplied to the feed water heater 3, the extracted steam 33 is supplied to the feed water heater 4, the extracted steam 34 is supplied to the desuperheater 1, and the heated feed water is It is supplied to the boiler 22. Boiler 22
Then, the feed water is further heated to generate steam to supply the generated steam to the turbine 23 to drive the turbine, and transmit rotational power to the generator 24 to generate power.

FIG. 2 shows an arrangement example around the desuperheater.

When the configurations of the desuper heater 1 and the feed water heater 2 are compared, the water chamber portions 1A, 2A and the trunk portion 1B
2B is the same, but the feed water heater 2 has a drain level and a regular drain seat, whereas the desuperheater 1 has a drain level and a regular drain seat. There is no difference.

The desuperheater 1 is installed on the floor 7 together with the feed water heater 3. The feed water supplied to the feed water heater 3 is heated by the turbine extraction steam 32, and the water chamber portion 1 </ b> A of the desuperheater 1.
To be supplied. The steam supplied to the water supply by the feed water heater 3 is supplied to the feed water heater 4 as a drain.

In the downstairs 8 of the floor 7, the extracted steam from the desuperheater 1 flows into the feed water heater 2 for heating the feed water from the condenser 25, and the feed water from the desuper heater 1 is fed to the turbine extracted steam 33.
A feed water heater 4 for heating is installed.

A steam pipe 5 from the body 1A of the desuperheater 1 to the body 2A of the feed water heater 2 is a floor 7
Therefore, even if the steam in the same steam pipe is drained and water is generated, no back flow to the trunk portion 1A of the desuperheater 1 having no liquid level is generated. Furthermore, by arranging the extraction piping from the desuper heater 1 straight downstairs, route planning can be performed in the shortest time.

In addition, by arranging the upstream feed water heater 4 of the desuperheater adjacent to the opposite side of the desuperheater 1, it is possible to realize an economical route plan for the water supply pipe connecting the two.

(Second Embodiment)
FIG. 3 shows an arrangement example around the desuperheater.

The positional relationship between the desuperheater 1, the feed water heater 2 into which steam from the desuperheater 1 flows, and the desuperheater upstream feedwater heater 3 is the same as that of the first embodiment.
The next-stage feed water heater 4 of the feed water heater 2 into which steam from the desuperheater flows is disposed on the same floor (plane) as the desuperheater and on the feedwater heater 2 into which the steam from the desuperheater flows.

Thereby, the steam pipe 5 from the trunk portion 1A of the desuperheater 1 to the trunk portion 2A of the feed water heater 2
Is extended in the vertical direction, even if drain is generated in the steam pipe 5, the desuperheater 1
In addition to the effect that the backflow to the body portion 1A does not occur, the shortest route can be realized by extending the water supply pipe extending from the water supply heater 2 to the water supply heater 4 vertically upward from the floor 8 as it is.

(Third embodiment)
Although this embodiment will be described with reference to FIG. 4, only the main parts are shown so that the difference from the other embodiments can be easily understood.

As shown in FIG. 4, the desuper heater 1 and the feed water heaters 2, 3, and 4 are arranged on the same plane,
And it arranges on the circumference in order of the number of stages of the water supply line. Since the feed water heaters to which the feed water pipes are connected are adjacent to each other, the feed water pipe design with the shortest route becomes possible. Further, since the steam pipes connecting the desuperheater and the feed water heater into which steam from the desuperheater flows are close to each other, an economical route can be realized.

Further, the steam pipe 5 from the body 1A of the desuperheater 1 to the body 2A of the feed water heater 2 is directed from the body 1A of the desuperheater 1 to the body 2A of the feed water heater 2 with respect to the horizontal plane. To be inclined. Thereby, the backflow to the trunk | drum 1A of the desuper heater 1 does not arise.

In addition, when there are two series of feed water heaters, the maintenance space for the feed water heater can be obtained by arranging the desuper heater and feed water heater on the circumference in a mirror arrangement (FIG. 5) or a parallel arrangement (FIG. 6). Can be shared and can contribute to space saving.

DESCRIPTION OF SYMBOLS 1 ... Desuperheater 2 ... Feed water heater in which extraction steam flows in from desuper heater 3 ... Feed water heater (front stage of desuper heater)
4 ... The next stage feed water heater 6 of the feed water heater into which the extraction steam flows from the desuper heater 6 ... the water supply system 7 ... the upper floor 8 of the de super heater installation floor ... Lower floor 9 ... Condensation system 22 ... Boiler 23 ... Turbine 24 ... Generator 25 ... Condenser 28 ... Main steam system 32, 33, 34 ... Extraction system 40 ... Heater drain system 50 ... Thermal power plant

Claims (7)

Thermal power generation having a feed water heater for heating feed water generated by condensing exhaust steam from a turbine, and a desuperheater that further heats the heated feed water by heat exchange with extracted steam from the turbine In the plant
A feed water heater to which steam that has been heat exchanged with the feed water at the desuper heater is supplied vertically below the desuper heater, and the water chamber of the desuper heater is a pre-stage feed water in the feed water system. A thermal power plant characterized in that it is arranged facing the water chamber of the heater in the same plane. The next stage feed water heater in the feed water system of the feed water heater into which the steam that has finished heat exchange with the feed water in the desuperheater flows is disposed above the feed water heater into which the steam flows. The thermal power plant according to claim 1. The next stage feed water heater of the feed water heater into which the steam that has finished heat exchange with the feed water in the desuperheater flows is disposed opposite the feed water heater into which the steam flows from the desuperheater. The thermal power plant according to claim 1. The thermal power plant according to claim 1, 2, or 3, wherein two feed water heaters are arranged in parallel. A thermal power plant characterized in that a feed water heater and a desuperheater are arranged on a plane circumference according to the order of deployment in a water supply system. 6. The thermal power plant according to claim 5, wherein two feed water heaters are arranged on a mirror surface position on the one series side and the other one series side. 6. The thermal power plant according to claim 5, wherein two feed water heaters are arranged in parallel on the one series side and the other one series side.

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