JPH04177002A - Boiler - Google Patents

Abstract

PURPOSE:To prevent drain from being generated in the main steam by controlling the temperature of the superheated steam to a specified temperature by making the superheated steam exchange heat with saturated water. CONSTITUTION:During the operation of a boiler a stop valve 10 at the inlet of steam of a hot boiler and a stop valve 12 at the outlet of steam of the hot boiler are respectively closed, stop valves 14 and 16 of the steam communicating pipe are both opened, part of the steam in a main steam pipe 5 which is heated by a heater 4 and the temperature of which is raised too high is led to a heat transfer pipe 9 through the steam communicating pipe 15 and the steam pipe 11 of the hot boiler, and the temperature of the steam is lowered by making the steam exchange heat with the boiler water in the water cylinder 1 through the heat transfer pipe 9. The steam the temperature of which is lowered is returned to the main steam pipe 5 through the steam pipe 13 and the steam communicating pipe 17 of the hot boiler. And, the main steam which is sent directly through a main steam temperature adjusting valve 18 and the temperature of which is not lowered and the steam the temperature of which is lowered are mixed and the temperature of the main steam as a whole is lowered. The temperature of the main steam the temperature of which is lowered is detected by a main steam temperature adjusting device 7 and the degree of opening of the main steam temperature adjusting valve 18 is so controlled as to bring the temperature of the mains steam to a specified temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a boiler system, and more particularly to a boiler system equipped with a heat exchanger for a warm can in a water barrel.

[Conventional technology]

In the conventional boiler device, as shown in FIG.
One end of the is attached. The other end of the heater 4 is connected to a main steam pipe 5, and a spray type attemperator 6 is provided in the middle of the main steam pipe 5. Spray water is injected into the interior of the spray type attemperator 6, and the temperature of the main steam is adjusted by the injected spray water. For example, if the main steam heated by the heater 4 rises in temperature too much,
The temperature of the main steam is detected by the main steam temperature controller 7, and the spray water flow rate control valve 8 is opened based on the detection signal, so that spray water is injected into the inside of the spray type attemperator 6 and the main steam is The temperature is reduced.

A heat transfer tube 9 is disposed inside the water barrel 1, and one end of the heat transfer tube 9 is connected to a warm can steam pipe 11 having a warm can steam inlet stop valve 10, and the other end is connected to a warm can steam outlet stop valve 12. The warm can steam pipes 13 each have a

[Problem to be solved by the invention]

However, the above conventional technology has the following problems.

In other words, if the boiler equipment is small and the boiler is operated at low load, the flow rate of main steam passing through the spray type sterilizer will decrease, resulting in poor mixing of the main steam and spray water, and the steam Temperature becomes difficult to control.

In addition, many boilers use soft water as spray water, and when this soft water is injected into the spray type desuperheater, the steam purity decreases due to the many impurities contained in the soft water. will be limited.

Furthermore, if the temperature of the main steam to be controlled is close to the saturation temperature, condensate may be mixed into the steam.

An object of the present invention is to provide a boiler device that can easily control steam temperature in a wide range of loads from low to high loads even in a small boiler, and can maintain steam purity in a good state. .

[Means to solve the problem]

In order to achieve the above object, the present invention provides a water barrel in which heat exchanger tubes for warming cans are provided, and a steam barrel that is connected to the water barrel via a water tube group and stores steam generated in the water tube group. , a heater connected to the steam barrel that heats steam coming from the steam barrel and sends it to the main steam pipe, wherein a part of the steam flowing in the main steam pipe is transferred to the water barrel. The present invention is characterized in that a means is provided for introducing the steam into the heat pipe to reduce its temperature and then returning the steam to the main steam pipe.

[Effect]

According to the above configuration, the temperature of the main steam can be reduced by flowing a part of the main steam through the heat transfer tube in the water barrel during operation of the boiler. When this cooled main steam is returned to the main steam pipe, the overheated main steam directly coming from the heater is mixed with the steam that has passed through the heat transfer tube in the water barrel, and the main steam as a whole is It becomes possible to reduce the temperature.

In this case, since the temperature of the main steam is reduced by the main steam itself, it is possible to avoid impurities from entering the main steam.
It becomes possible to maintain high steam purity.

In particular, since temperature control is performed by indirectly exchanging heat between the main steam and saturated water, the main steam does not drop below the saturation temperature, and no condensate is generated in the main steam. Furthermore, since the temperature of the main steam can be controlled by adjusting the flow rate of steam flowing to the heat transfer tubes in the water barrel, the temperature can be easily controlled even during low load operation.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings. Note that the same parts as in the prior art are denoted by the same reference numerals, and detailed explanation thereof will be omitted.

As shown in FIG. 1, in the boiler apparatus of the present invention, one end of a steam communication pipe 15 having a steam communication pipe stop valve 14 is connected to a main steam pipe 5.
The other end of this steam communication pipe 15 is connected to the hot can steam pipe 11.

Further, one end of a steam communication pipe 17 having a steam communication pipe stop valve 16 is also connected to the middle of the main steam pipe 5, and the other end of this steam communication pipe 17 is connected to the hot can steam pipe 13. On the main steam pipe 5, the connection part between the steam communication pipe 15 and the main steam pipe 5 is located upstream of the connection part between the steam communication pipe 17 and the main steam pipe 5, and the main steam pipe is located between the two connection parts. A steam temperature control valve 18 is provided. The opening degree of this main steam temperature control valve 18 is determined by the main steam v
It is controlled by a signal from a main steam temperature controller 7 disposed on the main steam temperature controller 5.

Next, the operation of this embodiment will be explained.

When the boiler is not operating, close the steam connection stop valve 1.
4 and 16, open the hot can steam inlet stop valve 10 and the warm can steam outlet stop valve 12, respectively, and supply warm can steam to the heat transfer tube 9, thereby heating the boiler water in the water barrel l. Since the boiler device can be maintained in a warm state, the boiler device can be started quickly.

During boiler operation, the warm can steam inlet stop valve 1° and the warm can steam outlet stop valve 12 are closed, and the steam communication pipe stop valve 14,
16 are both opened, and a part of the steam in the main steam pipe 5, which has been heated by the heater 4 and has become too hot, is guided to the heat transfer pipe 9 via the steam communication pipe 15 and the hot can steam pipe 11. The heat exchanger tube 9 exchanges heat with the boiler water in the water barrel 1 to reduce the temperature. The reduced temperature steam is transferred to the main steam pipe 5 via the warm can steam pipe 13 and the steam communication pipe 17.
Return to Then, the main steam whose temperature has not been reduced and which has been directly sent through the main steam temperature control valve 18 is mixed with the steam whose temperature has been reduced by the heat transfer tube 9, and the temperature of the main steam as a whole is reduced. The reduced temperature of the main steam is detected by the main steam temperature controller 7, and the opening degree of the main steam temperature control valve 18 is controlled so that the main steam temperature reaches a predetermined temperature.

In the above embodiment, the heat exchanger tube 9 for warm cans was used to reduce the temperature of the main steam, but there is a heat exchanger tube other than the heat exchanger tube 9 for warm cans in the water body 1, that is, a main steam attenuator. A heat exchanger tube exclusively for heating may be provided in the water barrel.

Furthermore, it is of course possible to use a conventional spray type attemperator together with the boiler apparatus shown in FIG.

〔Effect of the invention〕

As explained above, according to the present invention, the temperature of the main steam is reduced using the heat exchanger tube for warming the boiler when the boiler is stopped, so there is no need to install a new device as a desuperheater for the main steam. It is very economical.

In addition, since the superheated steam is controlled to a predetermined temperature by heat exchange with saturated water, it is possible to prevent the temperature from dropping below the saturation temperature and from generating condensate in the main steam, and to adjust the flow rate of steam flowing to the heat exchanger. By doing so, the temperature of the main steam can be controlled, so the temperature can be easily controlled even during low load operation.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram of a boiler device of the present invention, and FIG. 2 is an overall configuration diagram of a conventional boiler device. ■...Water barrel, 2...Steam barrel, 3...Water tube group, 4 river superheater, 5...Main steam pipe, 7...Main steam temperature controller,
9...Heat transfer tube, 10...Warm can steam inlet stop valve, 11.
13... Warm can steam pipe, 12... Warm can steam outlet stop valve, 14.16... Steam communication pipe stop valve, 15.17... Steam communication pipe, 18... Main steam temperature adjustment valve.

Claims (1)

[Claims] 1. A water barrel with heat transfer tubes for warming cans installed inside, a steam barrel connected to the water barrel via a water tube group and storing steam generated in the water tube group, and a steam barrel connected to the steam barrel. and a heater for heating steam coming from the main steam pipe and sending it to the main steam pipe, in which a part of the steam flowing in the main steam pipe is introduced into a heat transfer tube in the water body to reduce the steam temperature. A boiler apparatus characterized in that a means is provided for returning the steam to the main steam pipe after the steam is released.