JP2012021675A - Superheated steam generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a superheated steam generator whose size can be reduced.SOLUTION: The superheated steam generator 1 includes a primary coil 9, a tank 3, and a pipe 5. The tank 3 and the pipe 5 have a function of a secondary coil which is magnetically combined to the primary coil 9, and constitute a short circuit. By causing an AC current to flow the primary coil 9, the electromagnetic induction is generated so that the AC current flows in the pipe 5 and the tank 3. By this, a short current flows in the pipe 5 and the tank 3 to heat the pipe 5 and the tank 3. The saturated steam is generated inside the tank 3 by the heating and is sent to the pipe 5 to heat the saturated steam that flows in the inside of the pipe 5 for generating superheated steam.

Description

  The present invention relates to a superheated steam generator using electricity as a heat source.

  Superheated steam is steam at a higher temperature (for example, 400 to 500 ° C.) than saturated steam (about 100 ° C.), and can be used for heating or drying. There are a combustion boiler system and an electrical system in the superheated steam generator. The former is a method using a combustion boiler as a heat source used for generating superheated steam, and the latter is a method using electric power. An induction heating type superheated steam generator is a kind of electric system.

  In the induction heating, an alternating current is passed through an induction heating coil to generate an alternating magnetic flux, thereby causing an eddy current to flow through the conductive member to generate Joule heat, which is heated by Joule heat. As an induction heating type heating device, for example, a heating medium (oil etc.) is caused to flow in a spirally wound pipe to heat the heating medium by induction heating, and the heated heating medium is sent to a roll shell. There exists what heats a processed material on the surface of a shell (for example, refer to patent documents 1).

JP 2007-152651 A

  The production of superheated steam is divided into two processes: a process of heating water to generate saturated steam, and a process of heating saturated steam to generate superheated steam. Therefore, in both the combustion boiler method and the electric method, equipment and steam piping are arranged for each process. This was one cause that hindered miniaturization of the superheated steam generator.

  An object of this invention is to provide the superheated steam generator which can achieve size reduction.

  The superheated steam generator according to one aspect of the present invention that achieves the above object has the functions of a primary coil and a secondary coil that is magnetically coupled to the primary coil, and generates heat when a short-circuit current flows. A helical pipe member in which saturated steam flowing inside is heated by the heat generation to generate superheated steam, and the pipe member is connected to the pipe member so as to be able to supply the saturated steam to the pipe member, and the pipe member and a short circuit A tank member that generates heat when the short-circuit current flows to generate the saturated water vapor, and generates an electromagnetic induction by causing an alternating current to flow through the primary coil to generate an alternating current in the pipe member. And a control unit that controls the flow of the short-circuit current through the pipe member and the tank member.

  According to the present invention, a pipe member that functions as a secondary coil is connected to a tank member to form a short circuit, and an alternating current is caused to flow through the primary coil to cause an electromagnetic current to flow. A short-circuit current is passed through the pipe member and the tank member. The tank member and the pipe member generate heat by this short-circuit current, and saturated water vapor is generated in the tank member, and this saturated water vapor flows through the pipe member to generate superheated water vapor. Therefore, in the present invention, it is possible to share the electric system respectively used for the generation of saturated steam and superheated steam, so that the superheated steam generator can be downsized.

  In the above configuration, the tank member has an annular shape, and the pipe member and the tank member can function as the secondary coil.

  According to this configuration, since the tank member functions as a secondary coil in addition to the pipe member, electromagnetic induction can be generated in the pipe member and the tank member by passing an alternating current through the primary coil. Therefore, an alternating current (short circuit current) can be efficiently passed through the pipe member and the tank member.

  The said structure WHEREIN: The water supply pipe which supplies the water used for the production | generation of the said saturated water vapor | steam to the said tank member is further provided, and a part of said pipe member is wound around the said water supply pipe.

  According to this configuration, since the water supplied from the water supply pipe to the tank member is heated by a part of the pipe member wound around the water supply pipe, the generation efficiency of saturated water vapor in the tank member can be increased.

  The said structure WHEREIN: The said control part can let the alternating current of the frequency of commercial power supply flow through the said primary coil.

  According to this structure, since the alternating current of the frequency of a commercial power source is sent through the primary coil and the inverter is not used, the superheated steam generator can be downsized. The reason why the present invention does not need to use the inverter is that the superheated steam is generated not by induction heating but by using heat generated by passing a short-circuit current.

  According to the present invention, the superheated steam generator can be downsized.

It is a figure showing the whole superheated steam generating device composition concerning one embodiment of the present invention. It is a figure showing a section of a tank in which saturated steam is generated, and a part of a pipe in which superheated steam is generated. It is sectional drawing of the pipe along the arrow AA of FIG. It is a figure which shows the whole structure of the superheated steam generator which concerns on the modification of this embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing an overall configuration of a superheated steam generator 1 according to an embodiment of the present invention. FIG. 2 is a diagram showing a section of the tank 3 where saturated steam is generated and a part of the pipe 5 where superheated steam is generated. FIG. 3 is a sectional view of the pipe 5 taken along the line AA in FIG.

  The superheated steam generator 1 includes an iron core 7, a primary coil 9, a tank 3 and a pipe 5. The iron core 7 and the primary coil 9 are used for the outer iron type transformer. The iron core 7 includes a left leg portion 11, a central leg portion 13 and a right leg portion 15 which are arranged at intervals. A primary coil 9 is wound on the upper part of the central leg 13. The primary coil 9 is connected to an AC power source 17.

  The tank 3 is an example of a tank member and has an annular shape surrounding the lower portion of the central leg portion 13 of the iron core 7. The tank 3 is connected to the water supply pipe 21 on the upper surface 19 of the tank 3, and the water 23 used for generating saturated water vapor is supplied from the water supply pipe 21 to the tank 3. The water 23 supplied to the tank 3 is heated inside the tank 3 to generate saturated water vapor. On the upper surface 19 of the tank 3, the tank 3 is connected to one end of the pipe 5, and saturated water vapor generated inside the tank 3 is supplied to the pipe 5.

  The pipe 5 is spirally wound at the central portion of the central leg portion 13 and drawn out before the primary coil 9. The saturated water vapor flowing inside the pipe 5 is heated inside the pipe 5 to generate superheated water vapor. The superheated steam passes through the pipe 5 and is supplied to the location where the superheated steam is used.

  The tank 3 and the pipe 5 have a function of a secondary coil that is magnetically coupled to the primary coil 9. The material of the tank 3 and the pipe 5 is a material with good thermal conductivity and electrical conductivity (for example, copper or aluminum).

  A portion of the pipe 5 drawn from the central leg 13 and the lower surface 25 of the tank 3 are electrically connected by a wiring 27. Thereby, the tank 3 and the pipe 5 are electrically short-circuited to form a short circuit.

  The control unit 29 controls the alternating current that flows from the alternating current power supply 17 to the primary coil 9. The controller 29 receives signals from the temperature sensors 31 and 33. The temperature sensor 31 is attached to the tank 3, and the control unit 29 measures the temperature of the tank 3 based on a signal from the temperature sensor 31. The temperature sensor 33 is attached to the pipe 5, and the control unit 29 measures the temperature of the pipe 5 based on a signal from the temperature sensor 33. The control unit 29 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like.

  The operation of the superheated steam generator 1 will be briefly described. Since the pipe 5 and the tank 3 have a function as a secondary coil that is magnetically coupled to the primary coil 9, when an alternating current is passed through the primary coil 9 by the control unit 29, electromagnetic induction is generated and an alternating current is generated in the pipe 5 and the tank 3. Flows. Since the pipe 5 and the tank 3 constitute a short circuit, the alternating current flows to the pipe 5 and the tank 3 as a short circuit current, and the pipe 5 and the tank 3 generate heat due to Joule heat.

  When the tank 3 generates heat, the water 23 inside the tank 3 is heated, and saturated water vapor is generated inside the tank 3. In order to prevent the tank 3 from bursting due to saturated steam, the supply of the water 23 from the water supply pipe 21 is adjusted by the control unit 29 so that the inside of the tank 3 is not filled with the water 23. Saturated water vapor generated inside the tank 3 rises and is guided from one end of the pipe 5 into the pipe 5. Since the pipe 5 generates heat due to the short-circuit current, the saturated steam flowing inside the pipe 5 is heated by the pipe 5 to generate superheated steam.

  Based on the temperature of the tank 3 measured using the temperature sensor 31 and the temperature of the pipe 5 measured using the temperature sensor 33, the control unit 29 generates saturated water vapor inside the tank 3, and the pipe 5 The alternating current flowing through the primary coil 9 is controlled so that superheated water vapor is generated inside.

  The reason why superheated steam having a temperature higher than that of the saturated steam can be generated inside the pipe 5 is relatively long because the pipe 5 is formed in a spiral shape, and as shown in FIGS. This is because the thermal energy applied to the saturated water vapor per unit volume can be increased because it is considerably smaller than the longitudinal sectional area of the tank 3.

  The main effects of the superheated steam generator 1 according to this embodiment will be described.

  (1) According to the present embodiment, the pipe 5 functioning as a secondary coil and the tank 3 are short-circuited by the wiring 27 to form a short circuit, and by causing an alternating current to flow through the primary coil 9, electromagnetic induction is generated. An alternating current is passed through the tank 3 and the pipe 5, and a short-circuit current is passed through the tank 3 and the pipe 5. The short circuit current causes the tank 3 and the pipe 5 to generate heat to generate saturated water vapor inside the tank 3, and this saturated water vapor flows through the pipe 5 to generate superheated water vapor. Therefore, in this embodiment, the electric system and the piping system used for generating saturated steam and superheated steam can be made common, so the superheated steam generating apparatus 1 can be downsized.

  (2) For example, when a fluid (water, saturated steam) is heated by using a heater as a heating element, the heater has a relatively small heat transfer area and the fluid has a relatively slow temperature transfer. The problem is that the fluid being heated exceeds the heat resistance temperature of the heater and the heater itself is excessively heated. In particular, if the flow rate of the fluid is reduced, such a problem becomes significant. On the other hand, according to the present embodiment, since the tank 3 and the pipe 5 are heated by supplying a short-circuit current to the tank 3 and the pipe 5, the entire tank 3 and the entire pipe 5 serve as a heating element. Therefore, since the fluid is heated on the inner surface of the tank 3 and the inner surface of the pipe 5, the heat transfer area can be increased as compared with the heater, and as a result, the heating efficiency and the heating capacity can be increased. Thereby, it can prevent that a fluid and a heat generating body (the tank 3 and the pipe 5) are heated too much. Moreover, since the whole tank 3 and the whole pipe 5 become a heat generating body, according to this embodiment, an output can be enlarged compared with a heater.

  (3) According to the present embodiment, the secondary coil is configured by the annular tank 3 and the spiral pipe 5. Thereby, since an electromagnetic induction can be generated in the pipe 5 and the tank 3 by flowing an alternating current through the primary coil 9, an alternating current (short-circuit current) can be efficiently passed through the pipe 5 and the tank 3. In the present embodiment, the tank 3 has an annular shape surrounding the central leg 13 so that the tank 3 is a component of the secondary coil. However, since the tank 3 does not have a structure surrounding the central leg portion 13, an aspect in which the tank 3 is not a constituent element of the secondary coil is also possible.

  (4) In the induction heating type superheated steam generator, since the AC of the commercial power supply is converted to a high frequency by the inverter, the energy efficiency is poor and the inverter is essential. On the other hand, according to the present embodiment, a short-circuit current is passed through the pipe 5 and the tank 3 to cause the pipe 5 and the tank 3 to generate heat, and superheated steam is generated using the generated heat. Therefore, an inverter is not necessary, and it is only necessary to use the AC power supply 17 as a commercial power supply and pass an AC current having the frequency of the commercial power supply to the primary coil 9. Thus, according to this embodiment, since an inverter is unnecessary, the superheated steam generator 1 can be reduced in size and the manufacturing cost can be reduced. Moreover, since it is only necessary to flow an alternating current having a frequency of a commercial power source through the primary coil, energy efficiency can be improved as compared with the induction heating method.

  (5) According to the present embodiment, the controller 29 monitors the temperature of the tank 3 using the temperature sensor 31 and monitors the temperature of the pipe 5 using the temperature sensor 33, and based on these monitoring The temperature of the tank 3 and the pipe 5 is controlled by adjusting the alternating current flowing through the primary coil 9. Therefore, since the responsiveness is good when controlling the temperature of the tank 3 and the pipe 5, the temperature control of the tank 3 and the pipe 5 becomes easy.

  Next, a modification of this embodiment will be described. FIG. 4 is a diagram showing an overall configuration of a superheated steam generator 41 according to a modification of the present embodiment, and corresponds to FIG. The superheated steam generator 41 shown in FIG. 4 is different from the superheated steam generator 1 shown in FIG. 1 in that a part of the pipe 5 is wound around the water supply pipe 21. Specifically, one end of the pipe 5 is connected to the tank 3 on the upper surface 19 of the tank 3, and the pipe 5 is wound around the water supply pipe 21 on the upper surface 19 of the tank 3 and then wound around the central leg 13.

  According to the modified example, a part of the pipe 5 wound around the water supply pipe 21 functions as a water supply preheater, whereby a tank from the water supply pipe 21 is formed by a part of the pipe 5 wound around the water supply pipe 21. Since the water 23 supplied to the tank 3 is heated, the generation efficiency of saturated water vapor in the tank 3 can be increased.

DESCRIPTION OF SYMBOLS 1,41 ... Superheated steam generator 3 ... Tank (an example of a tank member)
5 ... Pipe (an example of a pipe member)
9 ... Primary coil 29 ... Control unit

Claims (4)

A primary coil;
A spiral pipe member having a function of a secondary coil that is magnetically coupled to the primary coil, generating heat when a short-circuit current flows, and heating the saturated water vapor flowing therein to generate superheated water vapor When,
A tank member that is connected to the pipe member so as to be able to supply the saturated water vapor to the pipe member and constitutes a short circuit with the pipe member, and generates saturated water vapor by generating heat when the short-circuit current flows. When,
A superheated steam comprising: a control unit that controls the flow of the short-circuit current through the pipe member and the tank member by causing electromagnetic induction by causing an alternating current to flow through the primary coil to flow an alternating current through the pipe member. Generator.   The superheated steam generator according to claim 1, wherein the tank member has an annular shape, and the pipe member and the tank member function as the secondary coil. A water supply pipe for supplying water used to generate the saturated steam to the tank member;
The superheated steam generator according to claim 1 or 2, wherein a part of the pipe member is wound around the water supply pipe.   The superheated steam generator according to any one of claims 1 to 3, wherein the control unit causes an alternating current having a frequency of a commercial power source to flow through the primary coil.

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