JPS5924326B2 - Steam heating device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for preventing shock effects occurring during draining of a steam heater.

In many thermal power plants, the forced draft outlet air duct is provided with a steam heater to preheat the feed air.

The heater is supplied with auxiliary steam or turbine bleed air, and heat exchange takes place between this steam and the forced draft outlet air.

The steam is collected as condensate through a drip pot to a low pressure feed water heater or condenser.

In the conventional structure, when condensate is discharged through the leg tube of each section of the steam heater to the condensate head pipe of each bank, a condensate discharge shock effect occurs.

This is because there is a pressure difference between banks or between sections, which obstructs drain discharge from low-pressure banks or sections, causing condensate to stagnate, and the condensate that has accumulated for a certain period of time to be discharged all at once. This is caused by

If the impact is large, damage or trouble will occur to drain piping, supports, valves, heat insulators, drip pots, level control devices, etc.

The present invention aims to prevent this drain discharge impact effect.

According to the present invention, a steam main pipe is provided in each of the high and low temperature banks of a steam heater, the steam main pipes are connected to each other by a pressure equalizing pipe, and a steam pipe having blind portions at both ends is provided for each bank. Install piping, connect each steam inlet main pipe to the center of the steam distribution pipe, connect the steam side leg tube for each section that performs heat exchange to each steam distribution pipe, and connect the drain piping from each bank. A device is provided for preventing outlet drain discharge shock effects of a steam heater directed to the same drain collection section.

It will be further described below with reference to the accompanying drawings.

Figure 1 is a schematic layout of the steam heater.
and the outlet air duct 4.

Steam heaters usually have 2 or 3
It is divided into blocks.

The illustrated one is divided into a block on the air inlet side, that is, a low temperature bank 1, and a block on the air outlet side, that is, a high temperature bank 2.

In addition, the A-A arrow view shows the low temperature bank 1, and the header 5
Each element grouped together is named section 6.

Figure 2 shows the piping system of the entire equipment for high-temperature tank 2, which similarly consists of a large number of sections. It is divided into a steam main pipe 7 and a high temperature bank steam main pipe 8, and passes through the steam side leg tubes 9 and 10 to each section of a low temperature bank 1 and a high temperature bank 2 (not shown).
After heat exchange, each drain side leg tube 1
1 and 12, and is discharged from the respective drain main pipes 13 and 14 to the steam side of the drip pot 18.

In this conventional structure, if there is a pressure difference between banks or between sections, the bank has a low outlet pressure.

Discharge from the section to the bank drain main pipe and drip pot is obstructed, and a drain discharge shock effect occurs.

FIG. 3 shows an embodiment of a drain discharge impact prevention device according to an embodiment of the present invention.

A steam main pipe 21 having a control valve 15 branches into a low temperature bank steam main pipe 7 and a high temperature bank steam main pipe 8.

Each main pipe 7, 8 has a throttle member or stop valve 2 near the heater.
6 and are interconnected by pressure equalizing pipes 25 with 6, providing steam pressure balance in this position.

Each main pipe 7, 8 is connected to the central part of a respective steam distribution pipe 23, 240 having a blind portion 22 at both ends, and a steam side leg tube 9, 10 to each section is connected to the respective steam distribution pipe. There is.

The piping on the outlet side may be similar to that shown in FIG.

According to this configuration, the presence of the pressure equalization pipe 25 provides a pressure balance between the respective distribution pipes 23 and 24, and since each distribution pipe is provided with blind portions 22 at both ends, each leg tube can be separated by 9° from each distribution pipe. 10, a pressure balance between each section is achieved and the outlet drain discharge shock effect can be largely prevented.

[Brief explanation of the drawing]

FIG. 1 is a side view and a front view schematically showing a steam heater. FIG. 2 is a schematic diagram showing conventional piping. FIG. 3 is a front view, a side view, a top view, and a schematic diagram showing a pressure equalizing pipe according to an embodiment of the present invention. In the figure, 1 is a low temperature bank, 2 is a high temperature bank, 3.4 is a wind passage, 6 is a section, 7, 8 are steam inlet main pipes, 9, 1
0 is steam side leg tube, 23° 24 is steam piping, 2
2 is a blind portion, 25 is a pressure equalizing pipe, and 26 is a stop valve (throttle member).

Claims (1)

[Claims] 1 A steam main pipe is installed in each high-temperature bank of the steam heater, the steam main pipes are connected to each other by a pressure equalizing pipe, and a steam distribution pipe having a blind portion at both ends is provided for each bank, so that the steam Connect each steam main pipe to the center of the distribution pipe, connect the steam side leg tube for each section that performs heat exchange to each steam distribution pipe, and connect the drain pipes from each bank to the same drain recovery section. A steam heating device characterized by leading to.