JP7407438B2 - fluid heating device - Google Patents

Description

The present invention relates to a fluid heating device such as a superheated steam generating device.

As shown in Patent Document 1, a conventional fluid heating device heats the fluid flowing through the conductor tube by induction heating the conductor tube, which is a secondary coil, in which the conductor tube is spirally wound. A turned inner tube element, an outer tube element provided outside the inner tube element and wound spirally, and a connecting tube element that fluidly connects the inner tube element and the outer tube element and connects them by short circuit. A device with the following is being considered.

The conductor tube configured as described above has a configuration in which the inner tube element and the outer tube element are electrically connected in parallel by the connecting tube element. Then, due to the magnetic flux generated by the induction coil, a short circuit current flows through the closed circuit composed of the inner tube element and the outer tube element. That is, a short circuit current flows through the inner tube element from one axial end toward the other axial end, and a short circuit current flows through the outer tube element from the other axial end toward one axial end.

However, in the above superheated steam generation device, the conductor tube forms one short circuit (closed circuit), so the short circuit current flowing through the entire conductor tube is the same, and the conductor tube generates Joule heat almost uniformly. For this reason, for example, Joule heat is wasted on the inlet side of the conductor pipe, resulting in poor fluid heating efficiency. Furthermore, the temperature difference between the inlet side and the outlet side of the conductor tube increases, resulting in increased thermal stress and the conductor tube becoming susceptible to deterioration.

JP2017-191680A

The present invention has been made to solve the above problems, and its main objective is to improve the heating efficiency of fluid by the secondary conductor pipe and to reduce the deterioration of the conductor pipe due to thermal stress. This is what I did.

That is, the fluid heating device according to the present invention heats the fluid flowing through the secondary conductor pipe by induction heating the secondary conductor pipe, which is a secondary coil, and Next-side conductor pipe The conductor pipe includes an inner pipe element and an outer pipe element that are spirally wound in opposite directions, and one axial end of the inner pipe element and the outer pipe element and the other axial end of the inner pipe element and the outer pipe element. and a connecting pipe element that fluidly connects them and short-circuits them, and the plurality of conductor pipe units are connected so that the fluid can flow therethrough. shall be.

According to such a fluid heating device, since the secondary side conductor tube has a plurality of conductor tube units in which the inner tube element and the outer tube element are short-circuited, the short-circuit current flowing through each conductor tube unit is adjusted, The Joule heating value of each conductor tube unit can be adjusted. As a result, the temperature of the fluid can be raised in stages in each conductor tube unit, and the heating efficiency of the fluid by the secondary conductor tube can be improved. Further, the temperature difference between the inlet side and the outlet side of each conductor tube unit can be reduced, and deterioration of the conductor tubes due to thermal stress can be reduced.
Note that each conductor tube unit includes an inner tube element and an outer tube element that are spirally wound in opposite directions, and one axial end of the inner tube element and the outer tube element and the other axial end of the inner tube element and the outer tube element. Since it has a connecting pipe element that fluidly connects them and short-circuits them, the connection structure for configuring the short-circuit can be simplified.

As a specific configuration for adjusting the short-circuit current flowing through each conductor tube unit, it is desirable that the plurality of conductor tube units have different numbers of turns of tube elements constituting the plurality of conductor tube units. With this configuration, the short circuit current flowing through each conductor tube unit can be adjusted simply by changing the number of turns of the tube element of the conductor tube unit.

In order to heat the fluid in stages by the secondary conductor pipe, it is desirable that the plurality of conductor pipe units be connected in series with each other.
For example, in a plurality of conductor tube units connected in series, by increasing the number of turns of the tube element toward the downstream conductor tube unit, the induced current can be increased as it goes toward the downstream conductor tube unit, and the Joule heating value can be increased to make it easier to heat the fluid to a high temperature.
Note that in a plurality of conductor tube units connected in series, the number of turns of the tube element may be decreased as the conductor tube units are located on the downstream side.

Further, the fluid heating device of the present invention includes a closed magnetic path core disposed inside the secondary conductor tube, and a primary coil to which an alternating current voltage is applied, the fluid heating device being arranged concentrically around the closed magnetic path core. The first conductor tube and the second conductor tube may be provided in a spiral shape.
The respective conductor pipes are arranged in the order of the second conductor pipe, the secondary conductor pipe, and the first conductor pipe from the inside in the radial direction, and the first conductor pipe, the second conductor pipe, and the second conductor pipe. The secondary conductor pipes are connected in series in order, and water or steam is introduced from the introduction port provided in the first conductor pipe, and the water or steam is introduced into the secondary conductor pipe via the second conductor pipe. It is desirable that the superheated steam be led out from the outlet port.
With this configuration, a first conductor pipe and a second conductor pipe are used as the primary coil, and a secondary conductor pipe, which is a secondary coil, is provided between the first conductor pipe and the second conductor pipe. Therefore, the first conductor tube and the second conductor tube are heated by electricity and are heated using the heat radiation of the secondary conductor tube, so that the heat radiation from the secondary conductor tube to the outside of the device can be reduced. , thermal efficiency can be increased.
In addition, the first conductor pipe, the second conductor pipe, and the secondary conductor pipe are connected in series in this order, and water or steam is introduced from the introduction port provided in the first conductor pipe, and the water or steam is introduced through the second conductor pipe. Since superheated steam is led out from the lead-out port provided in the secondary conductor pipe, the superheated steam generation device can be simplified and downsized.
In addition, the number of turns of the first conductor tube and the second conductor tube that form the primary coil, the current-carrying cross-sectional area of the conductor tube, and the diameter of the through hole of the conductor tube are determined by setting the heat generation ratio and the heat transfer area ratio to the fluid. The fluid flow rate ratio can be adjusted.

In order to prevent the heat dissipation of the secondary conductor pipe from leaking to the outside of the device and to safely heat the first conductor pipe and the second conductor pipe due to the heat dissipation of the secondary conductor pipe, it is necessary to It is desirable that a heat insulating material is filled between the secondary conductor pipe and the second conductor pipe and the secondary conductor pipe.
With this configuration, the thickness of the insulation material between the first conductor pipe and the secondary conductor pipe, and the thickness of the insulation material between the second conductor pipe and the secondary conductor pipe, The heat transfer ratio from the conductor tube to the first conductor tube and the second conductor tube can be adjusted.

According to the present invention configured in this way, it is possible to improve the heating efficiency of the fluid by the secondary side conductor tube and to reduce deterioration of the conductor tube due to thermal stress.

1 is a cross-sectional view schematically showing the configuration of a fluid heating device according to an embodiment of the present invention. It is a figure which shows typically the arrangement|positioning in the radial direction of the fluid heating device of the same embodiment. It is a figure showing the composition of the closed magnetic circuit iron core of the same embodiment. It is a side view which shows typically the structure of the secondary side conductor pipe of the same embodiment. It is a figure which shows the coil connection and the flow of the fluid of the same embodiment.

EMBODIMENT OF THE INVENTION Below, one Embodiment of the superheated steam generation apparatus based on this invention is described with reference to drawings.

<1. Device configuration>
The superheated steam generation device 100 according to the present embodiment generates superheated steam by causing a conductor tube to generate heat by electromagnetic induction to heat water flowing through the conductor tube. In addition, the superheated steam generation device 100 may be one that generates superheated steam by heating saturated steam generated externally, for example.

Specifically, as shown in FIGS. 1 and 2, the superheated steam generation device 100 includes a closed magnetic path iron core 2 and a primary coil to which an alternating current voltage is applied, which are arranged concentrically around the closed magnetic path iron core 2. A spiral (coiled) first conductor pipe 31 and a second conductor pipe 32, and a spiral (coiled) secondary side which is a secondary coil through which an induced current flows and is arranged around the closed magnetic circuit iron core 2. A conductor pipe 4 is provided.

As particularly shown in FIG. 3, the closed magnetic circuit core 2 has two rectangular annular core elements 21 and 22, and the leg core portions 21a and 22a of the two core elements 21 and 22 are combined so as to be in close contact with each other. It is composed of The two core elements 21 and 22 have the same shape, and each core element 21 and 22 has a rectangular ring shape made of laminated magnetic steel plates such that the width decreases from the outside to the inside. This is a wound core that has been transformed into. Note that grain-oriented electrical steel sheets are used as the magnetic steel sheets. By using these core elements 21 and 22, the cross-sectional shape of the closed magnetic circuit core 2 becomes a multi-stage shape.

The first conductor tube 31 and the second conductor tube 32 are each wound in a single layer, and the second conductor tube 32 is disposed on the inside in the radial direction, and the first conductor tube 31 is disposed on the outside in the radial direction. Further, an introduction port P1 is provided at one axial end of the first conductor pipe 31, and the other axial end of the first conductor pipe 31 is connected to the other axial end of the second conductor pipe 32. . Note that a flow rate adjustment valve 5 for adjusting the flow rate of water flowing into the first conductor pipe 31 is provided at or near the introduction port P1. Furthermore, an AC power supply (not shown) that applies an AC voltage is connected to a power supply terminal 61 provided at one axial end of the first conductor tube 31 and a power supply terminal 62 provided at one axial end of the second conductor tube 32. It is connected to the.

The first conductor tube 31 and the second conductor tube 32 are configured so that the wound portions of the conductor tubes 31 and 32 do not short-circuit with each other. Note that the winding portion refers to one spiral turn. Specifically, the first conductor tube 31 is subjected to an insulation treatment such as wrapping an insulator (not shown) around its outer circumferential surface, so that the wound portions of the first conductor tube 31 are not short-circuited to each other. It is configured not to. Furthermore, in the second conductor tube 32, the outer circumferential surfaces of the respective winding portions are wound with gaps so that they do not contact each other, so that the winding portions of the second conductor tube 32 are configured to avoid short-circuiting each other. has been done.

The secondary conductor pipe 4 is arranged between the first conductor pipe 31 and the second conductor pipe 32. Further, one axial end of the secondary conductor tube 4 is connected to one end of the second conductor tube 32, and the other axial end of the secondary conductor tube 4 is provided with an outlet port P2. Note that a temperature sensor 7 for controlling the temperature of superheated steam is provided at or near the outlet port P2. With such a configuration, the conductor pipes 31, 32, and 4 are arranged in the order of the second conductor pipe 32, the secondary conductor pipe 4, and the first conductor pipe 31 from the inside in the radial direction, and the first conductor pipe 31 , the second conductor pipe 32 and the secondary conductor pipe 4 are connected in series in this order.

As shown in FIG. 4, the secondary conductor pipe 4 has a plurality of (for example, two) conductor pipe units 4A and 4B, and these conductor pipe units 4A and 4B are free of water or water vapor. Connected for flow. Note that, hereinafter, one conductor tube unit 4A will be referred to as a first conductor tube unit 4A, and the other conductor tube unit 4B will be referred to as a second conductor tube unit 4B.

Each conductor tube unit 4A, 4B includes an inner tube element 41 and an outer tube element 42 that are spirally wound in opposite directions, and one end of the inner tube element 41 and the outer tube element 42 in the axial direction and the other end in the axial direction. It has connection pipe elements 43 and 44 that fluidly connect the ends and short-circuit them. A radial gap is formed between the inner tube element 41 and the outer tube element 42 when viewed from the axial direction. Moreover, each tube element 41, 42 is wound with a gap so that the outer circumferential surfaces of each wound portion do not contact each other.

The plurality of conductor tube units 4A and 4B have different numbers of turns of tube elements 41 and 42 that constitute them. In this embodiment, the inner tube element 41 of the first conductor tube unit 4A has a smaller number of turns than the inner tube element 41 of the second conductor tube unit 4B, and the outer tube element 42 of the first conductor tube unit 4A has a smaller number of turns than the inner tube element 41 of the second conductor tube unit 4B. The number of turns is smaller than that of the outer tube element 42 of the conductor tube unit 4B.

The plurality of conductor tube units 4A and 4B are connected to each other in series. Specifically, the other connecting tube element 44 of the first conductor tube unit 4A is connected to one connecting tube element 43 of the second conductor tube unit 4B, so that they are connected in series. Here, the other connecting pipe element 44 of the first conductor pipe unit 4A and one connecting pipe element 43 of the second conductor pipe unit 4B are a connection that connects the first conductor pipe unit 4A and the second conductor pipe unit 4B. It is composed of a tube 45.

Further, one axial end of the second conductor pipe 32 is connected to one connecting pipe element 43 of the first conductor pipe unit 4A, and the other connecting pipe element 44 of the second conductor pipe unit 4B has a lead-out port. P2 is provided. With this configuration, the fluid flowing from one of the connecting pipe elements 43 of the first conductor pipe unit 4A is branched by the connecting pipe element 43 into the inner pipe element 41 and the outer pipe element 42 of the first conductor pipe unit 4A, and then flows. The fluids flowing through the inner pipe element 41 and the outer pipe element 42 join together at the connecting pipe element 44 of the first conductor pipe unit 4A. The combined fluid flows through the connecting pipe 45 and flows into one connecting pipe element 43 of the second conductor pipe unit 4B. The fluid flowing in from one connecting pipe element 43 of the second conductor pipe unit 4B branches through the connecting pipe element 43 into the inner pipe element 41 and outer pipe element 42 of the second conductor pipe unit 4B, and flows into the inner pipe element 43. 41 and the outer pipe element 42 flows out from the outlet port P2 via the connecting pipe element 44 of the second conductor pipe unit 4B.

Further, the secondary conductor pipe 4 configured in this manner has a configuration in which the inner pipe element 41 and the outer pipe element 42 are electrically connected in parallel by the connecting pipe elements 43 and 44 in each of the conductor pipe units 4A and 4B. Become. That is, the secondary conductor pipe 4 of this embodiment has a configuration in which two parallel circuits are connected in series. Then, due to the magnetic flux generated by the first conductor tube 31 and the second conductor tube 32, which are the primary coils, one closed circuit is formed by the inner tube element 41 and the outer tube element 42 in the first conductor tube unit 4A, and a short circuit current is generated. flows, and in the second conductor tube unit 4B, one closed circuit is formed by the inner tube element 41 and the outer tube element 42, and a short circuit current flows. In other words, a short-circuit current flows through the inner tube element 41 from one axial end toward the other axial end, and a short-circuit current flows through the outer tube element 42 from the other axial end toward one axial end. flows.

In addition, in the superheated steam generation device 100 of this embodiment, as shown in FIGS. 1 and 2, there is a gap between the first conductor pipe 31 and the secondary conductor pipe 4, and between the second conductor pipe 32 and the secondary conductor pipe. 4 is filled with a heat insulating material 8. This heat insulating material 8 is also filled in the gaps between the wound portions of the second conductor tube 32, and is also filled between the inner tube element 41 and the outer tube element 42 of the secondary conductor tube 4. In this embodiment, a casing 9 is provided around the outer periphery of the first conductor tube 31, and a heat insulating material 8 is provided between the first conductor tube 31 and the casing 9. In addition, a heat insulating material 8 may be filled between the leg core portions 21a, 22a of the closed magnetic circuit core 2 and the second conductor pipe 32.

In the superheated steam generation device 100 of this embodiment configured in this way, an AC voltage is applied to the power supply terminal 61 provided on the first conductor pipe 31 and the power supply terminal 62 provided on the second conductor pipe 32 by an AC power supply. As a result, an alternating current flows through the first conductor tube 31 and the second conductor tube 32, and magnetic flux flows through the closed magnetic circuit iron core 2. Due to the magnetic flux, a short circuit current flows through each conductor tube unit 4A, 4B of the secondary side conductor tube 4, and each conductor tube unit 4A, 4B of the secondary side conductor tube 4 individually generates Joule heat. In addition, the first conductor tube 31 and the second conductor tube 32 generate Joule heat due to energization when an alternating current voltage is applied to them, and are also heated by heat transfer from the secondary conductor tube 4 .

Here, since each tube element 41, 42 of the first conductor tube unit 4A has a smaller number of turns than each tube element 41, 42 of the second conductor tube unit 4B, the induced electromotive force of the first conductor tube unit 4A is This is smaller than the induced electromotive force of the second conductor tube unit 4B. As a result, the short circuit current flowing through the first conductor tube unit 4A is smaller than the short circuit current flowing through the second conductor tube unit 4B. Thereby, the heating temperature is raised in stages from the first conductor tube unit 4A to the second conductor tube unit 4B.

As a result, as shown in FIG. 5, water introduced from the introduction port P1 of the first conductor pipe 31 flows through the first conductor pipe 31 and the second conductor pipe 32, and thereby It is heated by the conductor pipe 32 and becomes high temperature water or saturated steam. Thereafter, the high temperature water or saturated steam that has flowed into the secondary conductor pipe 4 from the second conductor pipe 32 is heated in stages by each conductor pipe unit 4A, 4B of the secondary conductor pipe 4, and becomes superheated steam. It is derived from the derivation port P2.

<2. Effects of this embodiment>
According to the superheated steam generation device 100 configured in this way, the secondary conductor pipe 4 has a plurality of conductor pipe units 4A and 4B in which the inner pipe element 41 and the outer pipe element 42 are connected in a short circuit. By adjusting the short-circuit current flowing through the units 4A and 4B, the Joule calorific value of each conductor tube unit 4A and 4B can be adjusted. As a result, the temperature of the fluid can be raised in stages in each conductor pipe unit 4A, 4B, and the heating efficiency of the fluid by the secondary conductor pipe 4 can be improved. Further, the temperature difference between the inlet side and the outlet side of each conductor tube unit 4A, 4B can be reduced, and deterioration of the tube elements 41, 42 due to thermal stress can be reduced.

Note that each conductor tube unit 4A, 4B fluidly connects one axial end of the inner tube element 41 and the outer tube element 42, which are spirally wound in opposite directions, and the other axial ends thereof. Since they are also short-circuited, the connection structure for configuring the short-circuit can be simplified.

Further, since the plurality of conductor tube units 4A, 4B have different numbers of turns of the tube elements 41, 42 constituting them, simply changing the number of turns of the tube elements 41, 42 of the conductor tube units 4A, 4B is sufficient. , the short circuit current flowing through each conductor tube unit 4A, 4B can be adjusted.

Furthermore, in the plurality of conductor tube units 4A and 4B connected in series, by increasing the number of turns of the tube elements 41 and 42 in the conductor tube unit 4B on the downstream side, the induced current can be made larger in the conductor tube unit 4B on the downstream side. By increasing the Joule heating value, it is possible to easily heat the fluid to a high temperature in stages.

In addition, a first conductor pipe 31 and a second conductor pipe 32 are used as the primary coil, and a secondary conductor pipe 4 as a secondary coil is provided between the first conductor pipe 31 and the second conductor pipe 32. Therefore, the first conductor pipe 31 and the second conductor pipe 32 are electrically heated and heated using the heat dissipation of the secondary conductor pipe 4, so that the heat from the secondary conductor pipe 4 to the outside of the device is heated. can reduce heat dissipation and increase thermal efficiency. In addition, the first conductor pipe 31, the second conductor pipe 32, and the secondary conductor pipe 4 are connected in series in this order, and water or steam is introduced from the introduction port P1 provided in the first conductor pipe 31, and the second conductor pipe 32 is connected in series. Since the superheated steam is led out from the lead-out port P2 provided in the secondary conductor pipe 4 via the conductor pipe 32, the superheated steam generation device 100 can be simplified and downsized. Here, in the first conductor tube 31 and the second conductor tube 32 that form the primary coil, the heat generation ratio and heat transfer to the fluid are determined by setting the respective number of turns, current carrying cross-sectional area of the conductor tube, and communication hole diameter of the conductor tube. The area ratio and fluid flow rate ratio can be adjusted.

Since the heat insulating material 8 is filled between the first conductor pipe 31 and the secondary conductor pipe 4 and between the second conductor pipe 32 and the secondary conductor pipe 4, the heat of the secondary conductor pipe 4 is radiated. It is possible to safely realize heating of the first conductor pipe 31 and the second conductor pipe 32 due to leakage of heat to the outside of the device and heat dissipation of the secondary conductor pipe 4. Here, depending on the thickness of the heat insulating material 8 between the first conductor pipe 31 and the secondary conductor pipe 4 and the thickness of the heat insulating material 8 between the second conductor pipe 32 and the secondary conductor pipe 4, The heat transfer ratio from the secondary conductor pipe 4 to the first conductor pipe 31 and the second conductor pipe 32 can be adjusted.

By making the secondary conductor tube 4 a secondary coil with multiple turns, the excitation current can be reduced and the leakage impedance can be reduced, so the cross-sectional area of the closed magnetic circuit iron core 2 can be made smaller and the amount of iron core used can be reduced. Iron loss can be reduced and thermal efficiency can be increased. Further, since the closed magnetic circuit iron core 2 is formed into a multi-stage shape to increase the surface area of the iron core, the cooling effect can be increased.

Furthermore, since the configuration is such that an AC power source that applies an AC voltage is connected to one axial end of the first conductor tube 31 and one axial end of the second conductor tube 32, the power supply wiring can be easily routed. .

<3. Modified embodiments of the present invention>
Note that the present invention is not limited to the above embodiments.
For example, in the embodiment, the first conductor tube 31 and the second conductor tube 32 are each wound in a single layer, but at least one of the first conductor tube 31 or the second conductor tube 32 is wound in two layers or more. It may be of.

Further, in the above embodiment, the secondary conductor pipe 4 has a configuration in which two conductor tube units 4A and 4B are connected in series, but it may have a configuration in which three or more conductor tube units are connected in series. In addition, the secondary conductor pipe 4 may have a configuration in which a plurality of conductor pipe units are connected in parallel.

Furthermore, in the embodiment described above, the winding diameters of the conductor tube units are the same, but they may be different.

Furthermore, each of the conductor tube units 4A and 4B in the above embodiment has a double tube structure, but may have a quadruple tube structure or an even number of tube elements. In this case, every two pipe elements are connected by a connecting pipe element. For example, it is conceivable that a plurality of the secondary conductor pipes 4 of the above embodiment are arranged concentrically.

In the embodiment described above, the conductor tubes 31 and 32 were used as the primary coils, but solid coils may also be used.

In the embodiment described above, a device that heats water or steam as a fluid has been described, but it may be a device that heats other liquids or gases.

In addition, it goes without saying that the present invention is not limited to the embodiments described above, and that various modifications can be made without departing from the spirit thereof.

100... Superheated steam generation device 2... Closed magnetic path iron cores 21, 22... Iron core elements 21a, 22a... Leg core portion 31... First conductor tube 32... Second conductor tube 4. ...Secondary side conductor pipe 4A...Conductor pipe unit 4B...Conductor pipe unit 41...Inner pipe element 42...Outer pipe elements 43, 44...Connecting pipe element P1...Introduction port P2...Output port 8...Insulating material

Claims (5)

A fluid heating device that heats fluid flowing through the secondary conductor pipe by induction heating a secondary conductor pipe that is a secondary coil,
A closed magnetic circuit iron core,
A primary coil to which an alternating current voltage is applied, comprising one first conductor tube and one second spiral conductor tube arranged concentrically around the closed magnetic circuit iron core,
The secondary conductor pipe is
a plurality of conductor pipe units arranged between the first conductor pipe and the second conductor pipe;
a connecting pipe arranged between the first conductor pipe and the second conductor pipe and connecting the plurality of conductor pipe units;
The plurality of conductor pipe units are
an inner tube element and an outer tube element spirally wound in opposite directions;
A fluid heating device comprising: a connecting pipe element that fluidly connects one axial end of the inner pipe element and the outer pipe element and the other axial end of the inner pipe element, and short-circuits them. The fluid heating device according to claim 1, wherein the plurality of conductor tube units have different numbers of turns of tube elements constituting the conductor tube units. The fluid heating device according to claim 1 or 2, wherein the plurality of conductor tube units are connected to each other in series. The respective conductor pipes are arranged in the order of the second conductor pipe, the secondary conductor pipe, and the first conductor pipe from the inside in the radial direction, and the first conductor pipe, the second conductor pipe, and the secondary conductor pipe. The conductor tubes are connected in series,
Water or steam is introduced from an introduction port provided in the first conductor pipe, and superheated steam is led out from an outlet port provided in the secondary conductor pipe via the second conductor pipe. A fluid heating device according to any one of claims 1 to 3. Any one of claims 1 to 4, wherein a heat insulating material is filled between the first conductor pipe and the secondary conductor pipe and between the second conductor pipe and the secondary conductor pipe. The fluid heating device described in .