JPH0227286Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a steam desuperheater used for controlling the temperature of superheated steam in a boiler.

A steam desuperheater sprays spray water into the steam flow to adjust the steam temperature (reduces the temperature), but as the steam temperature increases, the amount of spray increases and the mixture of steam and water increases. There was a problem where the condition worsened. Especially in the case of ultra-high temperature steam, it is becoming difficult to control the temperature.

The present invention improves this point and can effectively control the temperature of ultra-high temperature steam. The purpose is to provide a steam attemperator.

In other words, the present invention arranges the first stage attemperator and the second stage attemperator in series from the upstream side in the steam flow path without intervening any equipment, and the first stage attemperator A flow rate adjustment valve and a bypass valve are arranged in parallel in the spray water supply pipe communicating with the spray nozzle,
A steam system characterized in that a flow rate regulating valve whose opening degree is adjusted according to the steam temperature at the outlet of the second stage attemperator is disposed in the spray water supply pipe communicating with the spray nozzle of the second stage attemperator. It's in the desuperheater.

The present invention will be described below with reference to illustrated embodiments.

This steam attemperator consists of a first stage attemperator 4 and a second stage attemperator 9.

A steam pipe 1 that introduces ultra-high temperature superheated steam is connected to a first stage attemperator 4. This first stage attemperator is connected to a second stage attemperator 9 by a steam pipe 2.

A spray nozzle 5 is attached to the first stage attemperator 4 . A water supply pipe 8 for supplying spray water, a flow rate regulating valve 6, and a water supply pipe 8' are connected in series to this nozzle.

The superheated steam entering the first stage attemperator 4 is sprayed with spray water from the spray nozzle 5 to reduce its temperature, and then enters the second stage attemperator 9 via the steam pipe 2. The amount of this spray water for temperature reduction is higher than the flow rate of the spray water in the next second stage desuperheater 9 because the steam temperature is high and there is no danger of it becoming a drain, and moreover, it is effective for the mixing effect of steam and water. The flow rate is adjusted by a flow rate regulating valve 6 to maintain an appropriate amount.

A bypass valve 7 is placed side by side with the flow rate adjustment valve 6, and even in the event of a problem with the flow rate adjustment valve 6, a small amount of spray (enough to prevent thermal shock) will be sprayed through the bypass valve 7 to the spray nozzle 5. Water can be supplied.

A spray nozzle 10 is attached to the second stage attemperator 9 . This nozzle includes a water supply pipe 12 that supplies spray water, a flow rate adjustment valve 11, and a water supply pipe 1.
2' are connected in series.

The steam entering the second stage attemperator 9 is sprayed with spray water from a spray nozzle 10 to further reduce its temperature, and is then led out through the steam pipe 3.

Further, a desuperheater outlet thermometer 13 is provided at the outlet of the second stage desuperheater 9, and the spray nozzle is controlled by the flow rate adjustment valve 11 so that the temperature of the desuperheater exit thermometer 13 becomes a predetermined temperature. 10 flow rates are controlled. Therefore, in the second stage desuperheater 9, the first
Since water is sprayed onto the steam whose temperature has been reduced in the stage attemperator 4, the steam and water are effectively mixed.

Each attemperator is provided with an inner cylinder 14, 14', which protects the main pipe from thermal shock.

As described above, according to the steam attemperator according to the present invention, ultra-high temperature steam is first cooled by spraying water in the first stage attemperator without impairing the mixing effect of steam and water, and then in the first stage attemperator. Since the temperature is reduced to a predetermined temperature using the two-stage attemperator, a good temperature reduction effect can be obtained.

Overall, the effects obtained by the present invention are as follows.

(b) Two-stage spray has the following effects.

(a) The water/steam ratio per stage can be reduced, improving sprayability and mixing effects.

(b) In the event of a problem with the spray water flow rate adjustment valve, the other stage flow rate adjustment valves remain active and can be backed up. However, a bypass valve is installed in the first stage flow rate regulating valve, and this bypass valve secures a small amount of spray water, thereby making it possible to prevent thermal shock to the nozzle after maintenance of this flow rate regulating valve.

(b) A fixed amount of spray is applied to the first stage, and by increasing the amount of spray compared to the second stage, the following effects are achieved.

(a) The first stage is exposed to extremely high temperatures, so the thermal stress is high. However, since there is no change in the spray amount by adding a fixed amount, thermal fatigue can be prevented.

(b) Since the first stage has a high degree of superheating, there is no risk of it becoming a drain even if a little more spray water is added. On the other hand, since the water/steam ratio is lower in the second stage, appropriate sprayability and mixing effects can be obtained.

[Brief explanation of drawings]

The drawing is a system diagram of an embodiment of the steam attemperator according to the present invention. 1, 2, 3...Steam pipe, 4...First stage desuperheater,
5...Spray nozzle, 6...Flow rate adjustment valve, 7...
...Bypass valve, 8, 8'...Water pipe, 9...Second
Stage attemperator, 10... Spray nozzle, 11... Flow rate adjustment valve, 12, 12'... Water supply pipe, 13... Attemperator outlet thermometer, 14, 14'... Inner cylinder.

Claims (1)

[Scope of utility model registration request] A first stage attemperator and a second stage desuperheater are installed in the steam flow path from the upstream side.
The stage attemperators are arranged in series without intervening any equipment in between, and the flow rate adjustment valve and the bypass valve are arranged in parallel in the spray water supply pipe communicating with the spray nozzle of the first stage attemperator. A flow rate regulating valve whose opening degree is adjusted according to the steam temperature at the outlet of the second stage attemperator is installed in the spray water supply pipe that communicates with the spray nozzle of the second stage attemperator. Characteristic steam desuperheater.