JP3117367B2 - Steam temperature reducer with mixer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steam temperature reducer for reducing the temperature of main steam or reheat steam in a commercial or industrial boiler.

[0002]

2. Description of the Related Art The structure of a conventional steam temperature reducer will be described with reference to FIGS. In this example, the steam temperature reducer is installed in a straight portion of the communication pipe 7, and the steam temperature reducer body 3 and the communication pipe 7 are connected in a straight line, and the nozzle is provided on the upstream side of the steam temperature reducer body 3. The nozzle body 11 is inserted from the nozzle 14, and the spray nozzle 1 is disposed at right angles to the steam flow. The nozzle end cover 13 is held down by the nozzle support bolt 15 to fix the spray nozzle 1.

[0003] As shown in FIG. 6, a nozzle injection port 12 of a spray nozzle 1 is provided at a central angle of 60 ° behind a steam flow.
The rows and height directions are arranged in a zigzag pattern within the inner diameter of the protection cylinder 6 described later, and most of the water droplets of the spray water spouting from the porous nozzle injection port 12 adhere to the wall surface of the protection cylinder 6 and spray. The water liquid film 4 is formed. The attached spray water-liquid film 4 receives heat from the steam flow 5 flowing in the protection cylinder 6 and evaporates while staying on the wall surface of the protection cylinder 6.

[0004] In the conventional steam temperature reducer, when spray water injection is poor, that is, when the spray water is offset or the spray water particle size is large, the spray water liquid film 4 is locally thickened. The heat transfer to the spray water liquid film 4 becomes worse. For this reason, the evaporation completion distance of the spray water becomes long, and in order to protect the steam temperature reducer main body 3 or the connecting pipe 7 from erosion by the spray water droplets, the protection cylinder 6 having a considerable length is vaporized immediately after the spray nozzle 1. In fact, it is inevitable that the temperature reducer main body 3 be provided fixedly.

[0005]

Problems to be solved by the conventional steam temperature reducer when spraying of spray water is poor, that is, the problems to be solved are as follows: (1) The spray water liquid film is deviated and the thick film As a result, heat transfer from the steam becomes worse. (2) For this reason, spray water that cannot be completely evaporated is brought into the downstream device in the form of a drain, and causes problems such as drain attack and thermal stress. It is summarized in that.

The present invention solves these problems found in the conventional steam temperature reducer, and is good even when the spray state of the spray water is poor or when the spray water amount changes due to a change in the boiler load. It is an object of the present invention to provide a steam temperature reducer capable of performing stable evaporation and performing a stable steam temperature reducing action.

[0007]

In order to solve the above-mentioned problems in a steam temperature reducer for injecting spray water into a steam flow to reduce the steam temperature, the steam temperature reducer according to the present invention injects spray water. Low from the average position of the injection port
Disposed in the upstream steam flow of a length equivalent to the inner diameter of the reducer body ,
A configuration having a mixer having a plurality of mixing elements arranged on a circumference concentric with the reducer body is adopted.

The mixer employed in the present invention has a plurality of fixed blades having a fixed inclination angle in the same direction as a mixing element, and imparts a swirling flow to a steam flow passing therethrough, or a mixer in a direction opposite to each other. It is possible to adopt a device having an inclination angle and generating a turbulent vortex in a vapor flow passing therethrough.

These mixing elements are made to have an outer diameter slightly smaller than the inner diameter of the reducer main body, and are installed at the inlet of the protective cylinder of the steam temperature reducer, or when the protective cylinder is not provided, the mixer is attached to the steam temperature reducer main body. Attach using mounting feet.

[0010] In the present invention,With steam temperature reducer
IsMixerSpray water is reduced from the average position of the injection port
Located upstream of the length equivalent to the main body inner diameterBecauseSpray
This is preferable because the efficiency of stirring the steam flow with respect to water is increased.

[0011]

According to the present invention, by providing the mixer at the steam inlet of the steam temperature reducer, even if the spray water has a poor spraying property, the swirling flow or the turbulent turbulent flow is generated through the mixing device. Mixing and agitation are caused by flowing the changed steam flow, and the spray water liquid film thickness adhering to the protection cylinder or the like can be made thin and uniform.

[0012] Thus, heat transfer from the steam flow is promoted. This is because, by swirling the steam flow, etc., the residence length of the steam flow flowing in the protective cylinder can be increased, and the spray water is stirred as the turbulent steam flow, and the spray water liquid is further stirred. This is due to the improved heat transfer due to strong contact with the membrane.

[0013] In addition, the deviation of the steam temperature in the protective cylinder of the steam temperature reducer is equalized by turning the steam flow into a swirling flow or a turbulent vortex flow using a mixer in the same manner as described above. So the problem is solved.

According to the above operation, according to the steam temperature reducer of the present invention, heat can be effectively transferred from the steam flow to the spray water side, and the evaporation completion distance of the spray water can be shortened. The stability of the steam temperature at the outlet of the reducer will be obtained.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be specifically described based on the embodiments shown in FIGS. 1 to 4, the same components as those of the conventional apparatus shown in FIG. 5 are denoted by the same reference numerals.

(First Embodiment) First, a first embodiment shown in FIGS. 1 and 2 will be described. The first embodiment is a configuration example of a steam temperature reducer provided with a mixer 2 for generating a swirling flow in steam. In this embodiment, a case is shown in which the connecting pipe 7 and the steam temperature reducer connected thereto are connected in a straight line.
The same applies to the case where the connecting pipe 7 is connected at a right angle.

The steam temperature reducer body 3 connected to the connecting pipe 7
A nozzle nozzle 14 is provided at an upstream portion of the nozzle body 11, and a nozzle body 11 for supplying spray water to the spray nozzle 1 is provided here.
Is connected. The nozzle body 11 bends at a right angle downstream in the center of the reducer to reach the nozzle orifice 12. The spray nozzle body 11 is supported and fixed by nozzle support bolts 15.

A considerable length of protective sleeve 6 is provided slightly upstream of the nozzle orifice 12 to catch and evaporate the sprayed spray water and prevent it from damaging downstream piping equipment. In such a steam temperature reducer,
The mixer 2 of the present embodiment is installed at the entrance of the protective cylinder 6.

That is, by making the steam flow 5, which is a substantially parallel laminar flow before reaching the reducer, a swirling flow in the mixer 2, the mixing / stirring of the steam and the spray water is promoted. The mixer 2 is arranged on the upstream side of the steam flow 5 from the nozzle injection port 12. The mixer 2 has an inner diameter slightly smaller than the inner diameter of the reducer body 3 (same as the outer diameter of the protection cylinder 6).
This is a structure having eight fixed-wing-type swirling elements arranged on a circumference concentric with the reducer body 3.

The mixer 2 comprises a mixer body 21 and a mixer fixed blade 22 and is usually fixed to the protective cylinder 6. When there is no protection cylinder 6, it is fixed independently by the mixer mounting leg 24. Further, a distance L from the center of the nozzle injection port 12 to the mixer 2 shown in the figure is set to be approximately the same length as the inner diameter of the reducer body 3. The graph of FIG. 3 shows the transition of the mixing efficiency of spray water and steam when the distance between the mixer and the center of the nozzle injection port is changed. According to this, the point with the highest mixing capacity is 1.0D (the inner diameter of the reducer body 3 is D
), Which is the basis for setting L = about 1.0D.

As described above, the configuration of the steam temperature reducer provided with the mixer 2 makes it possible to spray the steam as a swirling flow against the spray water droplets having poor sprayability from the nozzle injection port 12. The steam and the spray water are mixed / stirred by flowing the water after the vicinity of the port 12, and the thickness of the spray water liquid film 4 attached to the protection cylinder 6 can be made thin and uniform. Thus, heat transfer from the steam flow 5 is promoted. This is because, by swirling the steam flow 5, the residence length of the steam flow 5 flowing in the protection cylinder 6 can be increased.

As for the deviation of the steam temperature in the protection cylinder 6 of the steam temperature reducer, the steam flow 5 is applied to the mixer 2 in the same manner as described above.
Thus, the problem is solved because the flow is leveled by forming a swirling flow.

(Second Embodiment) Next, a second embodiment shown in FIG. 4 will be described. According to the second embodiment, the first
This is a modification of the mixer 2 in the embodiment, and the basic configuration is not different from that shown in FIG.

FIG. 4 shows a mixer employed in the second embodiment. The configuration of the mixer 20 shown in FIG.
Unlike the mixer 2 used in the embodiment, all the mixing elements of the mixer 20 are configured so as not to have the same outflow angle. The outer diameter, thickness, etc. of the mixer 20 are basically the same as those of the mixer 2, but differ in the function for mixing the vapor stream 5.

That is, in the mixer 20 shown in FIG. 4, a mixer fixed blade 22 on the center side and a mixer fixed blade 23 on the outer peripheral side are provided concentrically and double with respect to the mixer body 21. And
The outflow directions of the mixer fixed blades 22 and the mixer fixed blades 23 are configured to be opposite to each other, and the steam flow 5 passing therethrough can be changed from a laminar flow to a turbulent vortex.

The structure of the second embodiment is the same as that shown in FIG. 1 except that the mixer is changed to the one having the above configuration. As described above, the configuration of the steam temperature reducer provided with the mixer 20 allows the steam to be sprayed from the spray 2 from the nozzle injection port 12 against the spray droplets having poor sprayability.
By flowing the turbulent turbulent flow in the vicinity of the nozzle orifice 12 by 0, mixing / stirring is promoted, and the thickness of the spray water liquid film 4 adhered to the protective cylinder 6 can be made thin and uniform.
Thus, heat transfer from the steam flow 5 is promoted.

This is because heat is improved by stirring the spray water with the steam flow 5 as a turbulent vortex and further bringing the spray water into strong contact with the spray water liquid film 4. Regarding the deviation of the steam temperature in the protection cylinder 6 of the steam temperature reducer,
As described above, since the steam flow 5 is leveled by making it a turbulent vortex, the problem is solved as in the case of the first embodiment.

As described above, in both the first embodiment and the second embodiment, heat is effectively transferred from the steam flow 5 to the spray water side, and the evaporation completion distance of the spray water is shortened. At the same time, the stability of the steam temperature at the outlet of the steam temperature reducer can be obtained.

[0029]

In the steam temperature reducer according to the present invention, the inner diameter of the reducer body is determined from the average position of the injection port for spraying spray water.
The following effects can be obtained by employing a configuration in which the mixer is disposed on the upstream side of the steam flow of a considerable length .

(1) Even when the spray from the spray nozzle is poor, the spray-diffusion effect of the spray water can be obtained, and the evaporating action of the spray water is improved.

(2) The steam temperature can be reduced stably even when the spray amount suddenly increases when the boiler load changes, and the performance of the steam temperature reducer is improved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a configuration of a steam temperature reducer with a mixer according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA in FIG. 1;

FIG. 3 is a graph showing a relationship between a mounting position and a stirring efficiency in a mixer employed in a steam temperature reducer according to the present invention.

FIG. 4 shows a mixer employed in a steam temperature reducer according to a second embodiment of the present invention, wherein (a) is a front view and (b) is (a).
Sectional drawing which follows the AA line of FIG.

FIG. 5 is a sectional view showing a configuration of a conventional steam temperature reducer.

6 is an enlarged view showing a configuration of a spray nozzle used in the steam temperature reducer shown in FIG. 5, (a) is a sectional view,
(B) is a plan view.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Spray nozzle 2 Mixer 3 Steam temperature reducer main body 4 Spray water liquid film 5 Steam flow 6 Protection cylinder 7 Communication tube 11 Nozzle main body 12 Nozzle injection port 14 Nozzle nozzle stand 15 Nozzle support bolt 20 Mixer 21 Mixer main body 22 Mixing Mixer fixed blade 23 Mixer fixed nozzle 24 Mixer mounting leg

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F22G 5/12

Claims (3)

(57) [Claims] 1. A steam temperature reducer for injecting spray water to a steam flow to reduce the steam temperature, wherein the inner diameter of the reducer main body is measured from an average position of an injection port for injecting the spray water.
A steam temperature reducer with a mixer, comprising: a mixer having a plurality of mixing elements arranged on a circumference concentric with the reducer body, which is disposed in a steam stream on the upstream side of a considerable length . . 2. The steam temperature reducer with a mixer according to claim 1, wherein said plurality of mixing elements are constituted by a plurality of fixed blades having a fixed inclination angle in the same direction. 3. The plurality of mixing elements are constituted by a plurality of fixed blades having fixed inclination angles opposite to each other.
A steam temperature reducer with a mixer according to the above.