JP4454877B2 - Steam dryness or wetness control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for arbitrarily controlling the dryness or wetness of steam supplied to various steam using apparatuses. Depending on the type of the steam using device, it is necessary to measure the so-called dryness X indicating the moisture content in the steam, that is, the ratio of the mass of the dry saturated steam to the total mass per unit volume of the steam. When the dryness is X, the wetness is represented by (1-X). In various boilers, equipment using steam power, drying equipment, and the like, for example, the operation efficiency and the drying state change depending on the moisture content in the steam, and thus the dryness or wetness is measured and controlled.
[0002]
[Prior art]
As a conventional dryness or wetness control device, for example, there is one described in Japanese Patent No. 2873640. This consists of a squeeze dryness meter or infrared wetness meter that measures the dryness of the steam, and a dryness and wetness control device that heats or cools the steam, and controls the dryness or wetness of the supplied steam. It can be arbitrarily controlled.
[0003]
[Problems to be solved by the invention]
The conventional dryness control device has a problem that the dryness or wetness cannot be controlled accurately and without time delay. This is because the cooling water is supplied into the steam to lower the dryness. Therefore, especially when the temperature difference between the cooling water and the steam is large, the cooling water becomes fine water droplets in the steam. It is impossible to mix uniformly and the dryness cannot be controlled with high accuracy. Moreover, since the said conventional thing supplies a heat medium to a coiled pipe and raises a dryness, after changing the temperature of a heat medium into a predetermined value, it supplies to a pipe and heats a vapor | steam It takes time and causes a time delay.
[0004]
Accordingly, an object of the present invention is to provide a steam dryness or wetness control device capable of accurately controlling the dryness or wetness without causing a time delay.
[0005]
[Means for Solving the Problems]
The means of the present invention taken to solve the above-mentioned problems include dryness or wetness measuring means for measuring the dryness or wetness of flowing down steam, and dryness or wetness adjusting means for adjusting the dryness or wetness of steam. A wetness adjusting means for controlling the dryness or wetness of the supplied steam to a predetermined value, wherein the dryness or wetness adjusting means includes a drain supply nozzle for supplying steam condensed drain, and an electromagnetic Consists of an induction heater, the drain supply nozzle is provided with a first fluid inlet to connect a branch vapor pipe, a drain pipe is connected to the second fluid inlet, and the electromagnetic induction heater is disposed in the pipe It is characterized by comprising a plurality of flat plate-like heating elements and a coil for generating magnetic flux attached to the outer periphery of the tube.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
When the dryness or wetness is controlled by using a drain supply nozzle and an electromagnetic induction heater to reduce the dryness, by supplying a drain that has almost no temperature difference between the condensed steam, Becomes a fine water droplet and can be uniformly mixed to control the dryness with high accuracy.
[0007]
On the other hand, when the dryness is increased, the dryness can be immediately increased by heating the steam without time delay by the electromagnetic induction heater. An electromagnetic induction heater is a stack of a plurality of stainless steel flat plates as a heating element in a pipe, and a coil that generates magnetic flux is attached to the outer periphery of the pipe, and the heating element itself is generated by high-frequency magnetic flux generated by this coil. When the electric power supplied to the coil is changed, the steam flowing down in the pipe can be heated and adjusted with little time delay.
[0008]
【Example】
Steam dryness or wetness control device comprising steam pipe 1 through which steam flows to control dryness or wetness, adjusting means 2 for adjusting dryness or wetness, and dryness or wetness measuring means 3 Configure. The steam pipe 1 is connected to the adjusting means 2 via the control valve 11 and the pressure sensor 20.
[0009]
The adjusting means 2 includes a drain supply nozzle 4 and an electromagnetic induction heater 5, and connects a branch steam pipe 7 that branches the steam pipe 1 to the first fluid inlet 6 of the drain supply nozzle 4 via a control valve 12. A drain pipe 9 to be described later is connected to the second fluid inlet 8. The drain from the drain pipe 9 and the steam from the branch steam pipe 7 are mixed by the nozzle 4 and supplied to the steam flow down pipe 10, thereby reducing the dryness of the flowing down steam and increasing the wetness. .
[0010]
A control valve 13, a steam trap 14, a heat exchanger 15, a control valve 16, and a branch steam pipe 17 are sequentially connected to the upstream side of the drain pipe 9. A cooling fluid supply pipe 18 and a discharge pipe 19 are connected to the heat exchanger 15, and the steam supplied from the branch steam pipe 17 is subjected to heat exchange to be drained. The drain condensed with steam is supplied from the drain pipe 9 to the drain supply nozzle 4 through the steam trap 14 and the control valve 13.
[0011]
The electromagnetic induction heater 5 includes a plurality of flat heating elements (not shown) arranged in a tube, and a coil 21 that generates magnetic flux on the outer periphery of the tube, and is electrically connected to the control box 22. The power and time supplied to the coil 21 by the control box 22 can be arbitrarily controlled.
[0012]
The control box 22 is also electrically connected to the dryness or wetness measuring means 3, the pressure sensor 20, and the control valves 11, 12, 13, 16, 23, 24. In the control box 22, the measured dryness or wetness is compared with the set input set value, and an opening signal to each control valve is issued so that the deviation between the two is set to zero, for example. The dryness or wetness of the supply steam in the steam pipe 1 is arbitrarily controlled.
[0013]
The drain condensed by heat exchange of the steam in the heat exchanger 15 is supplied from the drain pipe 9 to the drain supply nozzle 4, mixed with the steam, and injected into the pipe 10. The degree of dryness or wetness can be arbitrarily and accurately controlled.
[0014]
Further, the electromagnetic induction heater 5 can arbitrarily heat the steam flowing down in the steam pipe 5 without time delay.
[0015]
【The invention's effect】
As described above, according to the present invention, it is possible to accurately control the dryness or wetness of the flowing steam without causing a time delay.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a steam dryness or wetness control apparatus according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Steam piping 2 Dryness or wetness adjustment means 3 Dryness or wetness measurement means 4 Drain supply nozzle 5 Electromagnetic induction heater 7 Branch steam pipe 9 Drain pipe 15 Heat exchanger 17 Branch steam pipe 18 Cooling fluid supply pipe 21 Coil 22 Control box

Claims (1)

Provided with dryness or wetness measurement means for measuring the dryness or wetness of the steam flowing down, and dryness or wetness adjustment means for adjusting the dryness or wetness of the steam, and the dryness or wetness of the supplied steam The degree of dryness or wetness adjustment means is configured by a drain supply nozzle for supplying drain condensed with steam and an electromagnetic induction heater, and the first fluid inlet is connected to the drain supply nozzle. To connect the branch steam pipe, connect the drain pipe to the second fluid inlet, and attach the electromagnetic induction heater to a plurality of plate-like heating elements arranged in the pipe and the outer periphery of the pipe A steam dryness or wetness control device characterized by comprising a coil that generates a magnetic flux.

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