JP2001004104A - Desuperheater for superheated steam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water spraying nozzle which has an excellent spraying characteristic and good controllability from high load to low load regardless of the state of superheated steam and a desuperheater for the superheated steam. SOLUTION: An outer tube 16 is water-tightly protruded into the inside of a steam connecting tube 6 communicating with a superheater, the inside of the outer tube is partitioned into a plurality of independent water chambers 27, 28 and 29, spray nozzles 31, 32 and 33 communicating with each of water chamber are arranged on the outer tube, each of the water chambers is connected with each of opening and closing valves 40, 41 and 42, a plurality of water spray nozzles 15, wherein the opening and closing valve is connected with a water supply source 3 through a flow control valve, are provided, a temperature sensor sensing the temperature of the steam flowing through the steam connecting tube is provided, and after selecting a motor opening and closing valve according to the flow of the spray water to keep the steam temperature sensed by the temperature sensor at predetermined temperature, a flow control valve is controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a power generation facility,
The present invention relates to a superheated steam superheat reducing device for adjusting the temperature of superheated steam so that the temperature of superheated steam flowing into a steam turbine does not exceed a predetermined temperature.

[0002]

2. Description of the Related Art Steam that has been evaporated in a furnace and separated from water and water is sequentially heated by a flue gas until it reaches a required degree of superheating in a process of flowing through a primary superheater, a secondary superheater, and a tertiary heater.
Supplied to a steam turbine.

[0003] However, the combustion exhaust gas varies in both gas flow rate and temperature depending on the furnace load. For this reason, the superheated state of the steam in the superheater fluctuates, and a situation occurs in which the temperature of the superheated steam flowing into the steam turbine becomes higher than a predetermined temperature. The steam turbine is designed at a design temperature determined based on a predetermined temperature.If the temperature of the superheated steam becomes higher than the predetermined temperature, there is a problem in terms of the strength of the steam turbine, and the temperature of the superheated steam becomes higher than the predetermined temperature. It is adjusted so that it does not become. The temperature is adjusted by spraying water into the superheated steam line.

Referring to FIG. 3, a conventional apparatus for reducing superheat of superheated steam will be described.

[0005] A superheat reducing device for lowering the temperature of superheated steam is as follows.
It comprises a water spray nozzle 1, a flow control valve 2, a water supply pipe 3, a water supply controller 4, a steam temperature detector 7, and the like. The water spray nozzle 1 is provided in a steam communication pipe 6 upstream of a superheater 5. I have. FIG. 3 shows a primary superheater 5a in the steam communication pipe 6 from the upstream side,
An example in which a secondary superheater 5b and a tertiary superheater 5c are provided is shown. The water spray nozzle 1 is located upstream of the secondary superheater 5b and the tertiary superheater 5c, and the steam temperature detector 7 is a secondary superheater. 5
b, provided downstream of the tertiary superheater 5c.

[0006] The water spray nozzle 1 is connected to the steam communication pipe 6.
The water spray nozzles 1 are mounted so as to traverse the steam flow path at right angles, and the required number of water spray nozzles 1 are mounted at required intervals. Each of the water spray pipes 8 is connected to the water supply pipe 3 via the flow control valve 2, and the water supply pipe 3 communicates with a water supply source (not shown). The steam temperature detected by the steam temperature detector 7 is input to the feed water controller 4, and the feed water controller 4 turns off some of the plurality of flow rate regulating valves 2 according to the detected steam temperature. By adjusting the total amount of water sprayed from the water spray nozzle 1 or further adjusting the opening of the flow control valve 2 to spray water into the steam flowing through the steam communication pipe 6. The amount of water to be sprayed is adjusted, the steam temperature is lowered, and steam at a predetermined temperature is
0 is supplied.

FIG. 4 shows a conventional water spray nozzle 1. The water spray tube 8 is a single tube having a closed end and a required number of spray holes 9 formed therein. The diameter of the spray holes 9, the number of the spray holes 9, and the number of the water spray tubes 8 are determined so that the furnace can cope with the maximum load.

When the temperature of the superheated steam flowing through the steam communication pipe 6 is higher than a predetermined value, the water supply controller 4 determines the number of the water spray nozzles 1 for spraying water and adjusts the flow rate of the water spray nozzle 1 for spraying. The valve 2 is opened and the flow control valve 2 of the water spray nozzle 1 that does not spray is closed. Further, the opening of the flow control valve 2 of the water spray nozzle 1 to be sprayed is adjusted, and water is supplied from the water supply pipe 3 into the steam communication pipe 6 via the water spray nozzle 1. The supplied water is sprayed from the water spray pipe 8, evaporates by the heat of the superheated steam, and lowers the temperature of the superheated steam.

The temperature of the superheated steam flowing into the steam turbine 10 can be set to a predetermined temperature by making the amount of sprayed water correspond to the temperature and flow rate of the superheated steam.

[0010]

The number of the water spray nozzles 1, the diameter of the water spray pipes 8, the diameter of the spray holes 9 and the number of the spray holes 9 are set in accordance with the maximum load of the furnace. When the load on the furnace is not so large and the steam temperature is not high, the amount of water supply is naturally small and the amount of spray from the water spray pipe 8 is also small. When the spray amount per one water spray nozzle is small, the spray characteristics of the water spray pipe 8 are deteriorated, and when the opening degree of the flow control valve 2 is small, the amount of water jetted is changed, and Spray more or less. This may cause fluctuations in the steam temperature, or the jetted water may not be completely atomized and may be released into superheated steam in the form of water droplets. Furthermore, if the particle size increases and adheres to the tube wall without completely evaporating,
Temperature differences can cause damage.

The present invention has been made in view of the above circumstances, and provides a water spray nozzle having good spray characteristics and good controllability from a high load to a low load regardless of the state of superheated steam, and an apparatus for reducing superheated steam. .

[0012]

According to the present invention, an outer pipe projects watertightly into a steam communication pipe connected to a superheater, and the inside of the outer pipe is divided into a plurality of independent water chambers, and each of the water chambers is communicated. The present invention relates to a device for reducing superheat of superheated steam provided with a water spray nozzle having a spray hole provided in the outer pipe and connecting each water chamber to a water supply source via an on-off valve, and further comprising a steam communication pipe connected to a superheater. The pipe is protruded in a watertight manner, the inside of the outer pipe is divided into a plurality of independent water chambers, spray holes communicating with the respective water chambers are provided in the outer pipe, and each water chamber is connected to an on-off valve. It has a plurality of water spray nozzles connected to a water supply source via a regulating valve, and a temperature detector for detecting the temperature of steam flowing through the steam communication pipe is provided, and the steam temperature detected by the temperature detector is set to a predetermined temperature. To select and open and close the flow control valve, and further select the motor on-off valve. The present invention relates to a device for reducing superheat of superheated steam having a water supply controller that opens and closes, wherein the inside of the outer tube is divided concentrically and multiplexed to form a plurality of water chambers, and the lower end of each water chamber is connected via the outer tube. The present invention relates to a device for reducing superheat of superheated steam in which a required number of spray holes communicating with the lower end of each water chamber are provided adjacent to the inside of the steam communication pipe.

One water spray nozzle is divided into a plurality of water chambers, and water is sprayed independently from each of the water chambers. Therefore, by limiting the number of water chambers to be sprayed, regardless of the increase or decrease in the amount of spray water. Spraying can be performed within a favorable range of the spraying characteristics.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, the same components as those shown in FIG. 3 are denoted by the same reference numerals.

The water spray nozzles 15 are provided at several places in the steam communication pipe 6 between the primary superheater and the secondary superheater, the steam communication pipe 6 between the secondary superheater and the tertiary heater, and the like. The water spray nozzle 15 is attached to the steam communication pipe 6 so as to cross the steam flow path at right angles.

The water spray nozzle 15 will be described.

The outer tube 16 has a middle tube 17 and the middle tube 17 has an inner tube 1.
8 are sequentially arranged in a concentric multiplex manner, the lower end of the middle pipe 17 is shorter than the outer pipe 16, and the lower end of the inner pipe 18 is shorter than the middle pipe 17. For the outer tube 16 and the inner tube 18 for the middle tube 17,
Each upper end is long and protrudes upward.

A lower end plate 19 is fixed to the lower end of the outer tube 16 in a watertight manner, and a donut-shaped middle end plate 20 is fixed between the lower end of the inner tube 18 and the outer tube 16 in a watertight manner. A donut-shaped upper end plate 21 is fixed between the lower end of the middle tube 17 and the outer tube 16 in a watertight manner. Lower upper end plate 23 between the upper end of outer tube 16 and middle tube 17
Are fixed in a watertight manner, a middle upper end plate 24 is fixed between the middle pipe 17 and the inner pipe 18 in a watertight manner, and an upper end plate 25 is fixed to the upper end of the inner pipe 18 in a watertight manner.

Thus, a lower water chamber 27 is formed by the outer pipe 16, the inner pipe 18, the middle lower end plate 20, the lower lower end plate 19, and the upper upper end plate 25, and the outer pipe 16, the inner pipe 18, and the middle lower end are formed. A middle water chamber 28 is formed by the plate 20, the upper lower plate 21, and the middle upper plate 24, and an upper water chamber 29 is formed by the middle tube 17, the outer tube 16, the upper lower plate 21, and the lower upper plate 23.

The required number of rows and required number of rows of spray holes 31,
The spray holes 31 communicate with the lower water chamber 27, the spray holes 32 communicate with the middle water chamber 28, and the spray holes 33 communicate with the upper water chamber 29. I have. A water supply branch pipe 35 communicates with an upper end of the outer pipe 16, and a water supply branch pipe 3
6 communicate with each other, and a water supply branch pipe 37 communicates with an upper end of the inner pipe 18 protruding.

The water supply branch pipe 35, the water supply branch pipe 36, and the water supply branch pipe 37 join a water supply pipe 38, and communicate with the water supply pipe 3 via the water supply pipe 38. The water supply pipe 38 is provided with the flow control valve 2, the water supply branch pipe 35 is provided with a motor opening / closing valve 40, the water supply branch pipe 36 is provided with a motor opening / closing valve 41, and the water supply branch pipe 37 is provided with Is provided with a motor opening / closing valve 42. The flow control valve 2 and the motor on-off valves 40, 41, 42 are opened and closed by a water supply controller 4 based on the temperature detected by a steam temperature detector (not shown).

The operation will be described below.

When the amount of water spray is determined so as to control the steam temperature detected by the steam temperature detector to a predetermined value, the number of water spray nozzles 15 is determined from this, and the water supply controller 4 controls the corresponding flow control valve 2. Is opened. Further, the amount of water sprayed from the water spray nozzle 15 is adjusted. To adjust the water spray amount, first, the motor on-off valves 40, 41, and 42 are selected and opened.

In the case of a small spray amount, the motor on-off valve 41
Is opened, and the motor on-off valves 40 and 42 are closed.
Water is supplied from the water supply pipe 3 to the middle water chamber 28 via the water supply pipe 38 and the water supply branch pipe 36, and is sprayed into the steam communication pipe 6 from the spray hole 32.

In the case of a medium spray amount, the motor
0 and 42 are opened, and the motor on-off valve 41 is closed. From the water supply pipe 3 to the water supply pipe 38, the water supply branch pipe 3
7. Water is supplied to the lower water chamber 27 and the upper water chamber 29 via the water supply branch pipe 35, and is sprayed into the steam communication pipe 6 from the spray holes 31, 33. Here, the reason why the spray from the spray holes 31 and 33 is selected is that the sprayed water is not biased in the steam communication pipe 6.

In the case of a large spray amount, the motor on-off valve 4
0, 41, and 42 are all opened, and the spray holes 31, 3 are passed through the lower water chamber 27, the middle water chamber 28, and the upper water chamber 29.
Water is sprayed from 2,33.

As shown in FIG. 2, by selecting and opening the motor on-off valves 40, 41, 42 in accordance with the required amount of spray water, the amount of water sprayed from each of the spray holes 31, 32, 33 can be reduced. Spray characteristics can be selected in a good range. Further, by adjusting the degree of opening of the motor on-off valves 40, 41, and 42, and adjusting the amount of spray water within a range in which the spray characteristics of the spray holes 31, 32, and 33 are good, the temperature of the superheated steam can be adjusted accurately. Can do well.

In the above embodiment, a triple tube is used.
It may be a double tube or a quadruple tube. Also, the outer tube 16
The inside may be divided into independent water chambers and sprayed from each of the water chambers. The concentric multi-tube structure may be used, and the outer pipe 16 may be divided right and left by a flat plate along the axis. Good. Further, the motor opening / closing valve may be another opening / closing valve driven by another driving device, for example, a cylinder, and the flow rate adjusting valve 2 may be omitted.

[0030]

As described above, according to the present invention, the water spray nozzle protrudes watertightly from the outer pipe to the steam communication pipe connected to the superheater, and divides the outer pipe into a plurality of independent water chambers. A spray hole communicating with each water chamber is provided in the outer pipe, and each water chamber is connected to a water supply source via an on-off valve.Therefore, by limiting the number of water chambers to be sprayed, the amount of spray water can be increased or decreased. Regardless of the spray characteristics, it is possible to perform spraying in a good range, and furthermore, a plurality of water spray nozzles are provided, each water spray nozzle is communicated with a water supply source through a flow control valve, and the flow control valve is selectively opened and closed. By performing the selective opening and closing of the motor on-off valve, an excellent effect that various spray amount adjustments can be performed is exhibited.

[Brief description of the drawings]

FIG. 1 is a skeleton diagram of a main part showing an embodiment of the present invention.

FIG. 2 is a diagram showing a motor on-off valve and a change in a spray water amount according to the embodiment of the present invention.

FIG. 3 is an explanatory diagram of a conventional example.

FIG. 4 is a schematic sectional view of a conventional water spray nozzle.

[Explanation of symbols]

 2 Flow control valve 3 Water supply pipe 4 Water supply controller 6 Steam communication pipe 16 Outer pipe 17 Middle pipe 18 Inner pipe 27 Lower water chamber 28 Middle water chamber 29 Upper water chamber 31 Spray hole 32 Spray hole 33 Spray hole 40 Motor open / close valve 41 Motor on-off valve 42 Motor on-off valve

Claims (3)

[Claims] 1. An outer pipe which projects watertightly into a steam communication pipe connected to a superheater, divides the outer pipe into a plurality of independent water chambers, and has a spray hole communicating with each water chamber in the outer pipe. And a water spray nozzle that connects each water chamber to a water supply source via an on-off valve. 2. The outer pipe projects in a water-tight manner into a steam communication pipe connected to a superheater, the inside of the outer pipe is divided into a plurality of independent water chambers, and a spray hole communicating with each water chamber is provided in the outer pipe. A temperature detector for detecting the temperature of steam flowing through the steam connecting pipe, having a plurality of water spray nozzles connecting each water chamber to an on-off valve and connecting the on-off valve to a water supply source via a flow control valve. And a water supply controller that selects and opens and closes the flow control valve and further selects and opens and closes the motor on-off valve in order to bring the steam temperature detected by the temperature detector to a predetermined temperature. A superheat reduction device for superheated steam. 3. The outer pipe is divided into concentric multiplexes to form a plurality of water chambers, and the lower end of each water chamber is adjacent to the inside of the steam communication pipe via the outer pipe. 3. The apparatus for reducing superheated steam according to claim 1, wherein a required number of spray holes communicating with the lower end are provided.