JP5748202B2 - Superheated steam generator - Google Patents

Description

  The present invention relates to a superheated steam generator that generates superheated steam by induction heating.

  High-temperature superheated steam of 300 ° C to 600 ° C is generated by heating a tank filled with water to generate saturated steam of 100 ° C to 150 ° C, and heating the generated saturated steam to 300 to 600 ° C according to the flow. Is done. Induction heating may be used in heating saturated steam. The induction heating in this case is configured by arranging a heating element in which a large number of through-holes that generate Joule heat by being induced by an alternating current flowing through the coil are arranged inside a cylindrical shape of a coil in which a conducting wire is wound in a cylindrical shape. The saturated water vapor is heated by the heat of the heating element while flowing through the through hole.

JP 2005-233572 A JP 2010-210225 A

  In the superheated steam generator as described above, since the heater that heats water to obtain saturated steam is a tank filled with water, the heat transfer area in contact with water is small, the heat transfer efficiency is inferior, and the temperature of the water It is difficult to manage. Further, since the heater for heating the saturated steam heats the saturated steam that goes straight through the heating element, there is a problem that the heating element needs to be lengthened in order to transmit sufficient heat and the size of the heating element increases.

  The problem to be solved by the invention is to make the superheated steam generator small and compact, increase the heat transfer rate to water and saturated steam, and improve temperature controllability.

In order to solve the above-described problems, the present invention provides a superheated steam generator in which a conductor tube that generates heat by an alternating current flowing through the primary coil is wound around a closed magnetic circuit core around which the primary coil is wound. And a second induction heater in which a conductor tube that generates heat by an alternating current flowing through the primary coil is wound around a closed magnetic circuit core around which the primary coil is wound, and the first induction heater One end of the conductor pipe of the induction heater is connected to the water supply pipe, the other end is connected to one end of the conductor pipe of the second induction heater, and water is filled into the conductor pipe of the first induction heater. A superheated steam generating device that generates saturated steam and heats the generated saturated steam through the inside of a conductor pipe of the second induction heater to generate superheated steam , the primary steam generator of the second induction heater A coil is connected between two phases of a three-phase power source via a single-phase voltage controller, and the first induction heater The primary coil is a T-seat coil of a Scott connection transformer connected to the three-phase power source via a three-phase voltage controller, and the main coil of the Scott connection transformer is the primary coil of the second induction heater. It is configured to connect between two phases of a three-phase power source to which a coil is connected.

According to the present invention, since the closed magnetic circuit core around which the primary coil is wound is wound with the conductor tube through which water and saturated steam flow, the leakage magnetic flux due to the closed magnetic circuit core is extremely reduced, and the conductor is effectively The tube can be heated, and there is no harmful effect of induction heating of peripheral devices. Furthermore, the power factor is high, the power receiving capacity can be reduced, and the efficiency is increased. In addition, since the conductor tube is wound, its length can be increased, the heat transfer area is increased, and the temperature difference between the conductor tube temperature and water or saturated water vapor flowing through the conductor tube is reduced. The temperature controllability of the water vapor can be improved and the size and size can be reduced.

It is a circuit diagram of the heating part which concerns on the Example of this invention. It is a half section showing the structure of the induction heater concerning the example of the present invention. FIG. 1 is a configuration diagram showing the configuration of the conductor tube of FIG. 1, (a) is a plan view (b), a side view, and (c) is a partially enlarged view. It is a half section showing the structure of other induction heaters concerning the example of the present invention.

Embodiments of the present invention will be described with reference to the drawings. First, the induction heater used in the embodiment will be described with reference to FIGS. 2 and 3. In FIG. 2, 1 is an iron core constituting a closed magnetic circuit (hereinafter simply referred to as an iron core; the figure shows a leg iron core portion), 2 is a primary coil wound around the iron core, 3 is SUS wound around the iron core, etc. A conductor tube 4 is a brazed welded portion that is mechanically and electrically connected and fixed. The conductor tube 3 is mechanically and electrically connected and fixed between adjacent conductor tubes by TIG welding, and is electrically a single secondary coil in which the secondary coil is short-circuited. In the superheated steam generator in this embodiment, two induction heaters configured in this way are configured by connecting conductor tubes.
Hereinafter, the induction heater that generates saturated steam is referred to as a first induction heater, and the induction heater that generates superheated steam is referred to as a second induction heater.

  That is, in the generation of saturated steam, water is filled from the lower inlet 3a of the conductor tube 3 of the first induction heater into the conductor tube 3 to a predetermined position near the outlet 3b, and an AC voltage is applied to the primary coil 2. Apply. By applying this voltage, an alternating magnetic flux is generated in the iron core 1, an induced current is generated in the conductor tube 3, which is a secondary coil that is linked to the alternating magnetic flux, and the conductor tube 3 generates resistance heat due to this current. Water in the tube 3 is heated to produce saturated water vapor, and the saturated paper vapor is sent into the conductor tube 3 of the second induction heater.

At this time, although the water level decreases due to the generation and release of saturated water vapor, the water level is detected by a level meter or the like, and water is supplied in accordance with the decrease in the water level. Further, the temperature of water in the conductor tube 3, that is, the temperature of saturated water vapor is detected, and the current flowing through the primary coil 2 is controlled so as to reach a predetermined temperature (for example, 130 ° C.). In the secondary coils coiled Turn conductor pipe 3 wound, take total length of the guide body tube 3 is long, the temperature difference between the temperature and its water inside the conductive tube 3 increases the heat transfer area is small The temperature of the saturated water vapor can also be detected by detecting the temperature of the conductor tube 3.

To generate superheated steam, saturated steam sent from the first induction heater is introduced from the lower inlet 3 a of the second induction heater, and an AC voltage is applied to the primary coil 2. By applying this voltage, an alternating magnetic flux is generated in the iron core 1, an induced current is generated in the conductor tube 3, which is a secondary coil that is linked to the alternating magnetic flux, and the conductor tube 3 generates resistance heat due to this current. Saturated water vapor in the tube 3 is heated. Even in this case, the temperature of the superheated water vapor in the conductor tube 3 is controlled by a current flowing through the primary coil 2 so that the temperature of the conductor tube 3 is detected and a predetermined temperature (for example, 500 ° C.) is obtained.

As shown in FIG. 4, the conductor tube 3 of the induction heater is formed by winding the primary coil 2 between the primary coils 2, that is, along the iron core 1, and along the primary coil 2 on the outer periphery of the primary coil 2. Then, the conductor tube 3 is wound, the adjacent conductor tubes 3 are electrically and mechanically connected and fixed, and the primary coil 2 is wound along the conductor tube 3. When the secondary coil composed of the conductor tube 3 is arranged in this way, the magnetic flux crossing with the secondary coil increases, thereby increasing the current flowing through the conductor tube 3 and increasing the heating efficiency.

  By the way, large power reception of factory equipment must use a three-phase AC power supply. FIG. 1 shows a circuit in which two induction heaters according to an embodiment of the present invention can be connected without causing a large unbalance in the current between three phases (U, V, W) of a three-phase AC power source. Show. In FIG. 1, 5 is a three-phase AC power source, 6 is a three-phase voltage controller, 7 is a Scott connection transformer, 8 is a single-phase transformer, and 9 is a single-phase voltage controller.

The primary coil (conductor tube) of the first induction heater that generates saturated steam from water is the primary coil 2 of the T seat transformer of the Scott connection transformer 7, and the second coil that generates superheated steam from the saturated steam. The primary coil (conductor tube) of the induction heater is the primary coil 2 of the single-phase transformer. The three input terminals (U1, V1, W1) of the Scott connection transformer 7 are connected to the respective phases (U, V, W) of the three-phase AC power source via the three-phase voltage controller 6, respectively. The input terminals (V2, W2) of the primary coil 2 of the single-phase transformer 8 are connected to the V-phase and the W-phase in the illustrated example of the three-phase AC power supply via the single-phase voltage controller 9, respectively. With this connection, the current flowing through the primary coil of the first induction heater and the current flowing through the primary coil of the second induction heater can be individually controlled.

Note that if the T seat transformer and the main transformer are Scott-connected, and the number of turns between V 1 and W 1 of the main transformer is N, the number of turns between V 1 and O (connection part) and W 1 − The number of windings between O is N / 2 and the number of windings between U 1 and O of the T-seat transformer is (√3) N / 2. As long as this condition is satisfied, the T-seat transformer and the main transformer are single-phase transformers. It may be constituted by a vessel or may be a three-phase integrated type. In the case of the three-phase integrated type, if the cross-sectional area of both ends of the tripod iron core to which the T seat and the main transformer winding are applied is S, the central leg cross-sectional area is (√2) S.

Now, assuming that 130 ° C. saturated steam is obtained with the first induction heater and 500 ° C. superheated steam is obtained with the second induction heater, the caloric ratio is about 2: 1. When the primary coil of the first induction heater is connected between U and V of the three-phase power source and the primary coil of the second induction heater is connected between V and W, the current ratio is U: V: W = 1: 1.323: 0.5, the ratio of the maximum current to the minimum current is 2.65 times, and a large unbalance is generated in the current between the three phases, and such a connection increases the capacity of the power receiving facility. . However, if the primary coil of the first induction heater is the primary coil of the Scott connection transformer, the current ratio is U: V: W = 1: 0.661: 0.661 and the maximum current is obtained. And the minimum current ratio are 1.51 times, the large imbalance can be suppressed, and the increase in capacity of the power receiving equipment can be suppressed.

1 Closed magnetic circuit core (iron core)
2 Primary coil 3 Conductor tube 4 Welded part 5 Three-phase power supply (Three-phase AC power supply)
6 Three-phase voltage controller 7 Scott connection transformer 8 Single-phase transformer 9 Single-phase voltage controller

Claims (1)

A closed magnetic circuit core around which a primary coil is wound, a first induction heater in which a conductor tube that generates heat by an alternating current flowing through the primary coil is wound, and a closed magnetic circuit core around which a primary coil is wound, A second induction heater wound with a conductor tube that generates heat with an alternating current flowing in the primary coil, one end of the conductor tube of the first induction heater is connected to a water supply pipe, and the other end is Connected to one end of the conductor tube of the second induction heater, filled with water in the conductor tube of the first induction heater to generate saturated water vapor, and the generated saturated water vapor to the second induction heater A superheated steam generator for generating superheated steam by flowing through a conductor tube , wherein a primary coil of the second induction heater is connected between two phases of a three-phase power source via a single-phase voltage controller. The primary coil of the first induction heater was connected to the three-phase power source via a three-phase voltage controller And T locus coil cot connection transformer, characterized by comprising connecting the main seat coil of the Scott connection transformer between two phases of the three-phase power source connected to the primary coil of the second induction heater Superheated steam generator.

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