JPH02187501A - Device to start steam of exhaust heat boiler and operation of the same device to start steam generation - Google Patents

Abstract

PURPOSE:To prevent the development of water hammer by providing a bypass damper on the partition wall of a boiler and closing completely an inlet damper and opening completely the bypass damper to pass the exhaust gas to the side of the bypass at the time of initial starting of a boiler in its cold state. CONSTITUTION:With an exhaust gas boiler of water tube type which has natural circulation type, horizontal hair pin-water tubes an exhaust has inlet 17, inlet damper 19 in the space of the lower section of a horizontally placed hair-pin type water tube section, and bypass damper 20 which makes the exhaust gas bypass to the partition wall section 16 in the boiler are provided. At the time of initial starting in the cold state the inlet damper 19 is fully closed and the bypass damper 20 is fully opened, and an exhaust heat boiler is started so as to make the exhaust gas pass to the side of the bypass. After this state is continued for 30 minutes to about one hour according to the magnitude of the exhaust heat boiler, the inlet damper 19 is fully opened and bypass damper 20 is fully closed to develop steam in the water tube in the state the same as the ordinary gas passing state.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a natural circulation horizontal hairpin type waste heat water tube boiler, in which a forced circulation pump is removed from the downcomer piping of a conventional waste heat boiler, and the exhaust gas is By providing an inlet damper that partitions the lower part of the water pipe in the space between the inlet and the horizontal hairpin water pipe, and a bypass damper on the boiler internal partition wall, the horizontal hairpin water pipe waste heat boiler can be converted to a natural circulation system. This invention relates to an improved steam generation device for a waste heat boiler and an operating method for the steam generation device.
As shown in the figure, only a forced circulation pump (26) is placed in the downcomer pipe (2).

[Problem to be solved by the invention]

In conventional waste heat boilers, if the forced circulation pump installed in the downcomer piping breaks down, the waste heat boiler cannot operate, and additional power is required to operate the forced circulation pump. Customers have been requesting exhaust heat boilers that are not equipped with such problems as forced circulation pumps.

However, as shown in Figure 2, for example, the structure of the water tube group of an exhaust heat boiler from Maro is as follows: , at the time of initial startup, high-temperature exhaust gas enters from the exhaust gas inlet + 17) and heats the horizontal straight hairpin water pipe (4) from below, so steam bubbles begin to generate within the water pipe (4), but the initial cooling 1 At !1 o'clock, no upward flow had yet occurred in the water pipe. However, with cold water still surrounding the cold water pipe, subcooled boiling begins on the circular surface of the water pipe, and steam bubbles are generated, which suddenly come into contact with the cold water in the water pipe. As a result, the steam bubbles are crushed and a so-called water hammer phenomenon occurs, resulting in a large impact.

However, when the cold water in the water pipe is gradually heated and approaches the saturation temperature, water hammer as described above will no longer occur.

In addition, if an upward flow eventually occurs in the water pipe, and the internal water begins to rise along with bubbles, creating a smooth flow and normal water circulation, no problems will occur, but Takagata exhaust gas suddenly At the time of initial start-up in a cold state where the fluid flows in immediately, problems arise because the flow is not smooth.

The present invention provides a steaming device for a waste heat boiler 2 and a method for operating the steaming device, which prevents water hammer in the water pipes of the waste heat boiler at the time of initial startup in a cold state and performs smooth water circulation and steaming. It is something.

[Means to solve the problem]

1 is a natural circulation water device hairpin type water tube boiler, in which a space between the exhaust gas inlet and the hairpin type water tube section of the water device is provided with a space below the water section. The second part is a method for operating the steam generator of the above-mentioned type of waste heat boiler.

At the time of initial startup in a cold state, the inlet damper is fully closed and the bypass damper is fully closed, allowing exhaust gas to pass through the bypass side. That is, by keeping the boiler water pipes in the above state and then fully closing the inlet damper and the bypass damper, the normal gas flow state is restored and the water in the water pipes is steamed. It is possible to steam normally without causing overhammer.

In addition, by adopting the operating method of the steam generator of the present invention, the conventional handling standard of 60"C per hour or 1"C per minute when the temperature rise curve of the exhaust heat boiler 2 is in a cold state can be completely abolished. As a result, the exhaust heat boiler can be started without applying excessive thermal stress to each part of the boiler.

〔Example〕

Next, the final use will be explained using drawings.

Figure 1 is a schematic cross-sectional view of one embodiment of End 1. In a natural circulation horizontal hairpin water tube type waste heat boiler, an inlet damper is installed in the space below the exhaust gas inlet section 07) and the water device hairpin type water tube section. 9. Install a bypass damper in the boiler internal partition wall Qll to bypass the exhaust gas. At the time of initial start-up in the 0-cooled state, the person Rodanba α instant is fully closed and the bypass damper is fully opened to allow the exhaust gas to pass to the bypass side. Start up the waste heat boiler. That is, the waste scum enters the boiler water pipe section (4) from the rodan bar and gradually steams the water pipe depending on the amount of leakage.
After continuing this state for about i hours from 0 minutes, the inlet damper is fully turned and the bypass damper is fully opened, so that the water in the water pipe is gradually steamed as usual. In such a case, the water in the water pipe can be steamed normally without causing overhammer as described above.

In Figures 1 and 2, fl) is a steam drum, (2) is a downcomer pipe, (3) is an inlet header, (4) is a boiler water device hairpin type water tube, (6) is an outlet header, ( 6) is the riser pipe, (
7) is the water supply pipe, (8) is the water supply pump, (1) is the water supply pipe to the economizer pipe (ll), (l is the economizer outlet pipe, +11 is the water supply pipe to the steam drum, (14) is the main steam pipe , O Xun is the boiler casing, Moe is the boiler internal bulkhead, (17
) indicates the exhaust gas inlet, haze indicates the exhaust gas outlet, (lI indicates the inlet locomotive of the present invention, and Oka indicates the bypass damper.

〔Effect of the invention〕

In conventional water equipment hairpin type water tube waste heat boilers, forced circulation pumps were installed in the downcomer piping.
There was a drawback that if the forced circulation pump malfunctioned, the boiler would not be able to operate, but when it was finally completed, the system became a natural circulation type, which completely eliminated the above drawbacks, and there was no need for energy to operate the forced circulation pump. It became.

Furthermore, although the cold initial steaming of the hairpin type waste heat water tube boiler according to the present invention removes the forced circulation pump from the downcomer pipe, the steaming device of the waste heat boiler of the present invention is provided, By implementing an operating method in which the steaming equipment is completed, the exhaust heat boiler can be operated extremely smoothly without the occurrence of quarter hammer), which is extremely advantageous economically and also improves its operation. , there are numerous advantages in that labor savings for maintenance can be achieved.

[Brief explanation of the drawing]

Fig. 1 is a schematic sectional view of an embodiment of the steaming device for a natural circulation horizontal hairpin type waste heat water tube boiler of the present invention, and Fig. 2 is a sectional view of a conventional forced circulation type horizontal hairpin type waste heat water tube boiler. shows. Steam drum 2゜Boiler casing Wandering scum inlet Logumba forced circulation pump downcomer pipe 8. Inlet header 16, boiler bulkhead 1g, wandering waste outlet addition, bypass damper

Claims (1)

[Claims] 1. In a natural circulation horizontal hairpin type waste heat water tube boiler, an inlet damper is provided in the space between the exhaust gas inlet and the horizontal hairpin type water tube section to partition the lower part of the water tube section,
A steam generator for a waste heat boiler, further comprising a bypass damper provided on a partition wall within the boiler. 2. In the waste heat boiler according to claim 1, at the time of initial start-up in a cold state, an inlet damper that is provided in a space between the exhaust gas inlet and the horizontal hairpin type water pipe section and partitions the lower part of the water pipe section is provided. Fully close the boiler, fully open the bypass damper installed on the partition wall inside the boiler, let the exhaust gas pass through the bypass side, and let only the amount of exhaust gas leak from the inlet damper to gradually steam the water pipe, and after a desired fixed time, A method of operating a steaming device for a waste heat boiler, characterized in that steaming is performed by fully opening an inlet damper and fully closing a bypass damper.