HK1239800A1

HK1239800A1 - Fluid heating device

Info

Publication number: HK1239800A1
Application number: HK17113093.0A
Authority: HK
Inventors: 彻外村; 泰广藤本
Original assignee: 特电株式会社
Priority date: 2012-02-09
Filing date: 2017-12-11
Publication date: 2018-05-11

Description

Fluid heating device

The application is a divisional application of a patent application No. 201310047091, which is filed on 5.2.2013 and is entitled "fluid heating device".

Technical Field

The present invention relates to a fluid heating apparatus using an alternating current power supply.

Background

As shown in patent document 1, a fluid heating apparatus is known which generates a heated fluid by heating a fluid flowing inside a hollow conductor tube by supplying electricity to the conductor tube. In the fluid heating apparatus, an alternating current is applied from electrodes provided at both ends of the conductor tube, and an alternating current flows through the sidewall of the conductor tube, so that joule heat generated by the internal resistance of the conductor tube generates heat in the conductor tube itself. The fluid flowing through the conductor tube is heated by the heat generated by the conductor tube itself.

However, when an ac voltage is applied to both ends of the conductive pipe, the voltage is reduced due to the inductance of the conductive pipe, and therefore, there is a problem that the power factor of a circuit that applies an ac voltage to the conductive pipe is reduced.

Patent document 1: japanese patent laid-open publication No. 2011-86443

Disclosure of Invention

In order to solve the above problems, it is a primary object of the present invention to provide a fluid heating apparatus that can improve a circuit power factor and improve equipment efficiency by connecting a three-phase ac power supply to a conductor tube through which a fluid flows to perform energization heating.

That is, the fluid heating apparatus of the present invention is a fluid heating apparatus for heating a fluid flowing in a conductor pipe in which the fluid flows by applying a three-phase alternating voltage to the conductor pipe and heating the fluid flowing in the conductor pipe, and is characterized by comprising 3N conductor pipe layers formed by winding one conductor pipe or a plurality of conductor pipes electrically connected to each other in a spiral shape, wherein N is an integer of 1 or more, the 3N conductor pipe layers are arranged in a concentric circle shape such that respective resistance values are substantially equal and winding directions are the same, one end side of one of the adjacent conductor pipe layers is wound as a winding start portion and the other end side is wound as a winding end portion, the other end side of the other of the adjacent conductor pipe layers is wound as a winding start portion and the one end side is wound as a winding end portion, and the fluid heating apparatus heats the fluid flowing in the conductor pipe by applying a three-phase alternating voltage to the conductor pipe, and winding the conductor pipe layers in the winding direction, 2.… (3N-1)) conductor tube layer, and the winding start portion of the (N +1) th conductor tube layer, and the winding end portion of the first conductor tube layer and the winding start portion of the 3N (N +1) th conductor tube layer, are connected to any one phase of a three-phase ac power source, or the winding end portion of the N (N) th conductor tube layer and the winding start portion of the (N +1) th conductor tube layer are connected to any one phase of a three-phase ac power source, and the winding start portion of the first conductor tube layer and the winding end portion of the 3N (N +1) th conductor tube layer are connected to any one phase of a three-phase ac power source, thereby canceling out the entire magnetic fluxes generated by the 3N (3N) conductor tube layers.

According to this configuration, since the three-phase ac power supply is connected so that the impedance values of the respective conductor tube layers are substantially equal and the entire magnetic fluxes generated in the respective conductor tube layers of the 3N layers cancel each other out, the reactance generated in the respective conductor tubes can be reduced, and the power factor can be improved. Therefore, the equipment efficiency of the fluid heating device can be improved.

Preferably, the 3N-layer conductor tube layer is formed by continuously winding 3N layers of one conductor tube, and the fluid inlet and outlet formed by opening both end portions of the conductor tube are provided in a winding start portion of the first-layer conductor tube layer and a winding end portion of the 3N-th-layer conductor tube layer. Thus, a single conductor tube can be wound in multiple windings to form a single component, and the number of parts can be reduced, thereby facilitating handling. In addition, by connecting each phase of a three-phase ac power supply to the folded portions of the respective adjacent conductor tube layers, it is possible to heat the fluid with one fluid circuit.

Preferably, the 3N conductor tube layers are formed by winding M (M is 2, 3, … 3N) conductor tubes into 1 layer or winding them into a plurality of layers, and the fluid inlet and outlet are provided at the winding start portion or the winding end portion of the conductor tube layer where the openings are located at both ends of each conductor tube. Thus, since the 3N conductor tube layers are formed of M conductor tubes, at most M kinds of fluids can be heated simultaneously. Further, since the fluid inlet/outlet can be provided in at least one of the winding start portion and the winding end portion of any layer, the length of the conductor pipe (heating length) in which the fluid flows can be arbitrarily configured according to the heat capacity of the fluid.

Preferably, the 3N conductor tube layers are formed by winding 1 layer of each of 3N conductor tubes, and saturated steam is generated from water in 2N layers among the 3N conductor tube layers, and superheated steam is generated from the saturated steam in the remaining 1N layers. The ratio of the heat of the saturated steam at 130 ℃ generated from 20 ℃ water to the heat of the superheated steam at 700 ℃ generated from 130 ℃ saturated steam is about 2 to 1. Therefore, if a structure is adopted in which saturated steam is generated in the 2N layers and superheated steam is generated in the 1N layers, the current balance of the connected three-phase alternating-current power supply can be made approximately 1 to 1. Further, even when a low superheated steam temperature is used, an extreme imbalance such that the 1-phase current becomes zero does not occur. The current ratios of the three-phase ac power supplies at various superheated steam temperatures are as follows.

1 at 800 ℃: 1.04: 1.04

1 at 700 ℃: 1: 1

1 at 500 ℃: 0.90: 0.90

1 at 200 ℃: 0.70: 0.70

Preferably, the 1N layers for generating the superheated steam are disposed in the middle, the 1N layers among the 2N layers for generating the saturated steam are disposed on the inner side, and the remaining 1N layers are disposed on the outer side, so that the 1N layers for generating the superheated steam are sandwiched by the 2N layers for generating the saturated steam. Thus, the layer in which the high-temperature superheated steam flows is an intermediate layer sandwiched by the layers in which the saturated steam flows, and the heat transfer portion can be used as preheating for generating the saturated steam without unnecessarily releasing the heat of the superheated steam to the outside.

Preferably, the conductor tube layers connected to the respective phases of the three-phase ac power supply are electrically insulated between the respective phases, and the fluid heating apparatus further includes a current control device provided for the respective phases to individually control the current of the respective phases. In this way, the temperature of the connected conductor tube layers can be controlled individually.

Preferably, a magnetic material for a magnetic circuit is provided in at least one of the winding core hollow portion of the first conductor tube layer and the outer side of the 3N-th conductor tube layer. This allows magnetic fluxes generated by the passage of current through the conductive tube layers to pass through the magnetic body, and magnetic fluxes generated by the passage of current through the conductive tube layers can be easily cancelled out.

In addition, the fluid heating device applies alternating voltage to the conductor pipe with fluid flowing inside to heat the fluid flowing in the conductor pipe by electrifying and heating, characterized by comprising a fluid heating section composed of one conductor tube or a plurality of conductor tubes electrically connected to each other, an alternating voltage is applied from an alternating current power supply to both end portions of an even number of dividing elements formed by equally dividing the impedance value of the fluid heating portion into even number, the even number of dividing elements are even number of conductor tube layers which are constituted by winding the conductor tubes in a spiral shape and are arranged in concentric circles with each other, respective resistance values of the even number of conductor tube layers are equal to each other, and applying alternating voltage to two end parts of the even number of conductor tube layers to enable the directions of currents flowing in the conductor tube layers to be opposite, so that magnetic fluxes generated by the even number of conductor tube layers are offset with each other as a whole.

According to this configuration, the resistance value of the fluid heating portion is substantially equally divided into an even number of parts to form a plurality of divided elements, and the directions of currents flowing through the plurality of divided elements are made opposite to each other, so that the entire structure cancels out each other, thereby suppressing a voltage drop due to inductance of the conductor tube and improving the power factor. Therefore, the equipment efficiency of the fluid heating device can be improved.

Further, as described below, voltage drop due to inductance can be suppressed and power factor can be improved by various structures.

Preferably, the even number of conductor tube layers are arranged such that winding directions of adjacent conductor tube layers are opposite to each other, a voltage of one of positive and negative polarities of an alternating voltage is applied to one end side of each of the conductor tube layers, and a voltage of the other of positive and negative polarities of an alternating voltage is applied to the other end side of each of the conductor tube layers. In this way, all of the even number of conductor layers are connected to one polarity at one end side and to the other polarity at the other end side, so that the circuit configuration can be simplified.

Preferably, the even number of conductor tube layers are arranged such that winding directions of adjacent conductor tube layers are in the same direction, one end side of one of the adjacent conductor tube layers is located on the same side as one end side of the other conductor tube layer, the other end side of the one conductor tube layer is located on the same side as the other end side of the other conductor tube layer, a voltage of one of positive and negative polarities of an alternating voltage is applied to one end side of the one conductor tube layer and the other end side of the other conductor tube layer, and a voltage of the other of the positive and negative polarities of the alternating voltage is applied to the other end side of the one conductor tube layer and one end side of the other conductor tube layer. Even with such a configuration, voltage drop due to inductance can be suppressed, and power factor can be improved.

Preferably, the even number of conductor tube layers are continuously wound so that the winding directions of the adjacent conductor tube layers are the same direction, a voltage of one of positive and negative polarities of an ac voltage is applied to one end side of each of the conductor tube layers, and a voltage of the other of positive and negative polarities of an ac voltage is applied to the other end side of each of the conductor tube layers. Thus, a single conductor tube can be wound in multiple windings, and the fluid heating portion can be formed of a single structural member, whereby the number of parts can be reduced, and handling can be facilitated.

Preferably, the magnetic material for the magnetic circuit is provided in at least one of the winding core hollow portion of the conductor tube layer wound in a spiral shape and the outer side of the conductor tube layer.

The fluid heating apparatus according to the present invention is a fluid heating apparatus for heating a fluid flowing in a conductive pipe in which the fluid flows by applying an alternating voltage to the conductive pipe and heating the fluid by passing the alternating voltage, the fluid heating apparatus including a fluid heating unit including one conductive pipe or a plurality of conductive pipes electrically connected to each other, wherein an even number of dividing elements are formed by equally dividing impedance values of the fluid heating unit into even numbers, and directions of currents flowing through the dividing elements are opposite to each other, and magnetic fluxes generated in the even number of dividing elements are entirely cancelled out by each other.

According to this configuration, since the resistance value of the fluid heating portion is substantially equally divided into an even number of divided elements, and the directions of currents flowing through the divided elements are opposite to each other, the entire structures cancel each other out, and therefore, a voltage drop due to inductance of the conductor tube can be suppressed, and the power factor can be improved. Therefore, the equipment efficiency of the fluid heating apparatus can be improved.

Preferably, the even number of dividing elements are even number of conductor tube layers formed by winding the conductor tube in a spiral shape, the resistance values of the plurality of conductor tube layers are substantially equal, the even number of conductor tube layers are arranged concentrically such that the winding directions of adjacent conductor tube layers are the same, the even number of conductor tube layers are electrically connected in series, a voltage of one of positive and negative polarities of an alternating voltage is applied to one end side of the even number of conductor tube layers connected in series, and a voltage of the other of positive and negative polarities of the alternating voltage is applied to the other end side of the even number of conductor tube layers connected in series. Thus, an ac power supply may be connected to one end side and the other end side of the even number of conductor tube layers connected in series, and the circuit configuration can be simplified.

Preferably, the magnetic material for the magnetic circuit is provided in at least one of the winding core hollow portion of the conductor tube layer wound in a spiral shape and the outer side of the conductor tube layer. Thus, magnetic fluxes generated by the conduction of electricity to the conductor tube layers can pass through the magnetic body, and the magnetic fluxes generated by the conduction of electricity to the conductor tube layers can be easily offset with each other.

The conductor pipe is not limited to a spiral shape, and may be a straight pipe shape. This makes it possible to simplify the structure of the conductor tube.

According to the present invention having such a configuration, the three-phase ac power supply is connected to the conductor tube through which the fluid flows to heat the fluid, thereby improving the power factor of the circuit and the efficiency of the apparatus.

Drawings

Fig. 1 is a diagram schematically showing the configuration of a fluid heating apparatus according to a first embodiment.

Fig. 2 is a diagram showing a fluid heating section structure of the fluid heating apparatus according to the first embodiment.

Fig. 3 is a wiring diagram of the various conductor tube layers of the first embodiment.

Fig. 4 is a diagram showing a fluid heating section structure of the fluid heating apparatus according to the first embodiment.

Fig. 5 is a wiring diagram of the various conductor tube layers of the first embodiment.

Fig. 6 is a diagram showing a characteristic comparison test circuit according to the first embodiment.

Fig. 7 is a diagram showing a fluid heating section structure of a fluid heating apparatus according to a second embodiment.

Fig. 8 is a diagram showing a fluid heating section structure of a fluid heating apparatus according to a second embodiment.

Fig. 9 is a diagram showing a fluid heating section structure of a fluid heating apparatus according to a second embodiment.

Fig. 10 is a diagram showing a fluid heating section structure of a fluid heating apparatus according to a second embodiment.

Fig. 11 is a diagram showing a circuit configuration of a spiral coil test of the 1-layer winding according to the second embodiment.

Fig. 12 is a diagram showing a circuit configuration of a spiral coil test of the 2-layer winding according to the second embodiment.

Fig. 13 is a diagram showing a circuit configuration of a spiral coil test of a 2-segment 2-layer winding according to the second embodiment.

Fig. 14 is a wiring diagram of the various conductor tube layers of the modified embodiment.

Fig. 15 is a diagram showing a fluid heating section structure according to a modified embodiment.

Fig. 16 is a wiring diagram of the respective conductor tube layers of the modified embodiment.

Fig. 17 is a diagram showing a circuit configuration of a straight tube type conductor tube test according to a modified embodiment.

Description of the reference numerals

100 … fluid heating device

2 … conductor tube

3 … fluid heating part

3a … first layer of conductor tube layer

3b … second layer of conductor tube layer

3c … layer conductor layer of the third layer (layer conductor layer of the 3N layer)

4 … three-phase AC power supply

Detailed Description

(first embodiment)

An embodiment of the fluid heating apparatus according to the present invention will be described below with reference to the drawings.

As shown in fig. 1, a fluid heating apparatus 100 according to the present embodiment is configured such that a three-phase ac power supply 4 is connected to a hollow conductor tube 2, a fluid (for example, water, saturated steam, superheated steam, or the like) flows through the conductor tube 2, a three-phase ac voltage is applied to the conductor tube 2 to directly supply current, and the conductor tube 2 is heated by joule heat generated by an internal resistance of the conductor tube 2, thereby heating the fluid flowing through the conductor tube 2.

Specifically, the fluid heating apparatus 100 includes a fluid heating section 3, and the fluid heating section 3 is formed by winding a single conductor tube 2 or a plurality of conductor tubes 2 electrically connected to each other into a spiral conductor tube layer of 3N (N is an integer of 1 or more) layers.

The fluid heating section 3 may have various structures as shown in fig. 2 and 3.

The fluid heating section 3 shown in fig. 2 is composed of one conductor tube 2, and has a 3N-layer (N is an integer of 1 or more) conductor tube layer formed by equally dividing the impedance value of the entire fluid heating section 3 into 3N parts. In the present embodiment, three conductor tube layers 3a, 3b, and 3c each having N1 are used.

The three conductor tube layers 3a, 3b, 3c comprise: a first conductor tube layer 3a formed by winding one conductor tube 2 in a spiral shape from one end side to the other end side; a second conductor tube layer 3b connected to the other end of the first conductor tube layer 3a and spirally wound in the same direction as the winding direction of the first conductor tube layer 3a from the other end side to one end side; and a third conductor tube layer 3c connected to one end of the second conductor tube layer 3b and spirally wound in the same direction as the winding direction of the second conductor tube layer 3b from one end side to the other end side.

By configuring the three conductor tube layers 3a, 3b, and 3c in this way, one conductor tube layer (first layer) of adjacent conductor tube layers (for example, first and second layers) is wound with one end side as a winding start portion and the other end side as a winding end portion, and the other conductor tube layer (second layer) of adjacent conductor tube layers (for example, first and second layers) is wound with the other end side as a winding start portion and the one end side as a winding end portion. In addition, the conductor tube 2 is insulated with an insulator or a gap every winding. For example, it is conceivable to use the conductor tube 2 that is subjected to insulation processing such as providing an insulating layer on the outer circumferential surface. Or each plurality of turns can be divided into one group, and the groups are insulated. The number of groups is determined by the value of the current flowing through the conductor tube 2.

And adjusting the number of windings, the length of the tube, the diameter of the tube, the wall thickness, the diameter of the windings and the height of the windings to ensure that the impedance values of the three layers of conductor tube layers 3a, 3b and 3c are basically equal. In the present embodiment, the pipe diameter, the wall thickness, the number of windings, and the like of the conductor pipes 2 constituting the respective conductor pipe layers 3a, 3b, and 3c are made the same.

The three layers of conductor tube layers 3a, 3b, and 3c are formed by continuously winding three layers in the same winding direction and winding the layers into concentric circles. In other words, the three conductor tube layers 3a, 3b, and 3c of the fluid heating section 3 configured as described above are continuously and integrally configured. Here, it is preferable that the magnetic substance for a magnetic path is provided in at least one of the winding core hollow portion of the first conductor tube layer 3a and the outer side of the third conductor tube layer 3 c. In the case where the conductor tube layers are 6, 9, and … 3N layers, one conductor tube 2 is continuously wound concentrically from one end side to the other end side and then from the other end side to the one end side with the winding direction in the same direction.

Since the fluid heating section 3 configured as described above is formed by winding one conductor tube 2, fluid inlets and outlets 2Px and 2Py formed to open from both end portions of the conductor tube 2 are provided at the winding start portion of the first conductor tube layer 3a and the winding end portion of the third conductor tube layer 3 c. In the present embodiment, the fluid inlet/outlet 2Px at the winding start portion of the first conductor tube layer 3a is located on one end side (upper end side in fig. 2), and the fluid inlet/outlet 2Py at the winding end portion of the third conductor tube layer 3c is located on the other end side (lower end side in fig. 2). The fluid inlets and outlets 2Px and 2Py have structural portions such as flanges for connecting external pipes.

In the fluid heating unit 3, the phases (U-phase, V-phase, and W-phase) of the three-phase ac power supply 4 are connected, and a U-phase voltage, a V-phase voltage, and a W-phase voltage are applied to the three conductive tube layers 3a, 3b, and 3c, whereby the magnetic fluxes generated in the three conductive tube layers 3a, 3b, and 3c are cancelled out as a whole.

Specifically, as shown in fig. 3, the first phase (V-phase) of the three-phase ac power supply 4 is connected to the winding end portion of the first conductor tube layer 3a and the winding start portion of the second conductor tube layer 3b, the second phase (W-phase) of the three-phase ac power supply 4 is connected to the winding end portion of the second conductor tube layer 3b and the winding start portion of the third conductor tube layer 3c, and the third phase (U-phase) of the three-phase ac power supply 4 is connected to the winding start portion of the first conductor tube layer 3a and the winding end portion of the third conductor tube layer 3 c. That is, the three conductor tube layers 3a, 3b, and 3c have a circuit configuration in which the three-phase ac power supply 4 is connected in a delta configuration, and the phase difference between the ac currents flowing through the respective conductor tube layers 3a, 3b, and 3c is 60 degrees.

That is, a V-phase voltage is applied to a terminal provided in a turn-back portion connecting a winding end portion of the first conductor tube layer 3a and a winding start portion of the second conductor tube layer 3 b. A W-phase voltage is applied to a terminal provided in a turn-back portion connecting a winding end portion of the second conductor tube layer 3b and a winding start portion of the third conductor tube layer 3 c. Further, U-phase voltage is applied to terminals provided at or near the end of the conductive tube 2, which is the winding start portion of the first conductive tube layer 3a, and at or near the end of the conductive tube 2, which is the winding end portion of the third conductive tube layer 3 c.

By connecting the three-phase ac power supply 4 to the three conductor tube layers 3a, 3b, and 3c and applying a three-phase ac voltage, the sum of the resultant magnetic flux vectors generated by the currents flowing through the conductor tube layers 3a, 3b, and 3c is zero, so that the reactance generated in the conductor tube layers 3a, 3b, and 3c can be reduced, and the circuit power factor can be improved.

The fluid heating unit 3 shown in fig. 4 is composed of three conductive pipes 2 electrically connected to a three-phase ac circuit including a three-phase ac power supply 4, and has 3N layers (N is an integer of 1 or more) of conductive pipes formed by equally dividing the impedance value of the entire fluid heating unit 3 by 3N parts. In the present embodiment, three conductor tube layers 3a, 3b, and 3c having N equal to 1 are used.

The three conductor tube layers 3a, 3b, 3c comprise: a first conductor tube layer 3a formed by winding one conductor tube 2 in a spiral shape from one end side to the other end side; a second conductor tube layer 3b formed by winding one conductor tube 2 in a spiral shape from the other end side to one end side; the third conductor layer 3c is formed by winding one conductor tube 2 in a spiral shape from one end side to the other end side.

The winding directions of the conductor tube layers 3a, 3b and 3c are the same, and the number of windings, the tube length, the tube diameter, the wall thickness, the winding diameter and the winding height are adjusted to make the impedance values of the conductor tube layers 3a, 3b and 3c basically equal. In the present embodiment, the pipe diameter, the wall thickness, the number of windings, and the like of the conductor pipes 2 constituting the respective conductor pipe layers 3a, 3b, and 3c are made the same. When the conductor tube layers are 6, 9, and … 3N layers, the conductor tubes 2 wound from one end side to the other end side and the conductor tubes 2 wound from the other end side to the one end side are alternately arranged so that the winding directions of the conductor tubes 2 are the same.

In the fluid heating section 3 configured as described above, each of the conductor tube layers 3a, 3b, and 3c is formed of one conductor tube 2, and the fluid inlets and outlets 2Px and 2Py are provided at the winding start portion and the winding end portion of each of the conductor tube layers 3a, 3b, and 3c, respectively, and the fluid inlets and outlets 2Px and 2Py are located on one end side (upper end side in fig. 4) and the other end side (lower end side in fig. 4). The fluid inlets and outlets 2Px and 2Py have structural portions such as flanges for connecting external pipes.

In the fluid heating section 3, by applying the three phases (U phase, V phase, W phase) of the three-phase ac voltage from the three-phase ac power supply 4 to the three conductor tube layers 3a, 3b, 3c, the magnetic fluxes generated in the three conductor tube layers 3a, 3b, 3c cancel each other out as a whole.

Specifically, as shown in fig. 5, the first phase (V-phase) of the three-phase ac power supply 4 is connected to the winding end portion of the first conductor tube layer 3a and the winding start portion of the second conductor tube layer 3b, the second phase (W-phase) of the three-phase ac power supply 4 is connected to the winding end portion of the second conductor tube layer 3b and the winding start portion of the third conductor tube layer 3c, and the third phase (U-phase) of the three-phase ac power supply 4 is connected to the winding start portion of the first conductor tube layer 3a and the winding end portion of the third conductor tube layer 3 c. That is, the three conductor tube layers 3a, 3b, and 3c have a circuit configuration in which the three-phase ac power supply 4 is connected in a delta configuration, and the phase difference between the ac currents flowing through the respective conductor tube layers 3a, 3b, and 3c is 60 degrees.

That is, a V-phase voltage is applied to terminals provided at or near the end of the conductive tube 2, which is the winding termination portion of the first conductive tube layer 3a, and at or near the end of the conductive tube 2, which is the winding start portion of the second conductive tube layer 3 b. W-phase voltage is applied to terminals provided at or near the end of the conductive tube 2, which is the winding termination portion of the second conductive tube layer 3b, and at or near the end of the conductive tube 2, which is the winding start portion of the third conductive tube layer 3 c. U-phase voltages are applied to terminals provided at or near the end of the conductive tube 2 serving as a winding start portion of the first conductive tube layer 3a and at or near the end of the conductive tube 2 serving as a winding end portion of the third conductive tube layer 3 c.

Further, the first phase (V phase) of the three-phase ac power source 4 may be connected to the winding start portion of the first conductor tube layer 3a and the winding end portion of the second conductor tube layer 3b, the second phase (W phase) of the three-phase ac power source 4 may be connected to the winding start portion of the second conductor tube layer 3b and the winding end portion of the third conductor tube layer 3c, and the third phase (U phase) of the three-phase ac power source 4 may be connected to the winding end portion of the first conductor tube layer 3a and the winding start portion of the third conductor tube layer 3 c.

By connecting the three-phase ac power supply 4 to the three conductor tube layers 3a, 3b, and 3c and applying a three-phase ac voltage, the sum of the resultant magnetic flux vectors generated by the currents flowing through the conductor tube layers 3a, 3b, and 3c is made zero, so that the reactance generated in the conductor tube layers 3a, 3b, and 3c can be reduced, and the circuit power factor can be improved. Since the fluid inlets and outlets 2Px and 2Py are provided in the respective conductor tube layers 3a, 3b, and 3c, the fluids flow through the respective conductor tube layers 3a, 3b, and 3c, and therefore, at most three kinds of fluids can be heated simultaneously.

In addition, in the case where the fluid heating section 3 shown in fig. 4 is used and superheated steam is generated from water, it is conceivable that saturated steam is generated from water in 2N layers among the conductor tube layers of the 3N layers and superheated steam is generated from saturated steam in the remaining 1N layers. In this case, from the viewpoint of utilizing thermal energy, it is preferable that the 1N layers generating superheated steam are disposed in the middle, the 1N layers among the 2N layers generating saturated steam are disposed on the inner side, and the remaining 1N layers are disposed on the outer side, and the 1N layers generating superheated steam are sandwiched by the 2N layers generating saturated steam.

Specifically, water is introduced into the first and third conductor tube layers 3a and 3c to generate saturated steam, and the saturated steam generated in the conductor tube layers 3a and 3c is introduced into the second conductor tube layer 3b to generate superheated steam. With such a configuration, the phase current balance of each phase of the connected three-phase ac power supply 4 can be made approximately 1 to 1. Further, by forming the conductor tube layer 3b through which high-temperature superheated steam flows as an intermediate layer sandwiched between the conductor tube layers 3a and 3c through which saturated steam flows, the heat transfer portion can be used as preheating for generating saturated steam without unnecessarily releasing the heat of the superheated steam to the outside.

Next, a test for improving the power factor of the fluid heating apparatus 100 configured as described above will be described. In the following experiments, a single-phase ac power supply having a frequency of 800Hz was used to clearly show the tendency of comparison.

The cross-sectional area of the handle is 8.042mm²A copper wire having a diameter of 3.2mm was wound in a spiral shape by 60 turns to form coil layers, and the first layer coil layer, the second layer coil layer and the third layer coil layer were wound from one end side to the other end side, respectively, and were arranged in concentric circles so that the winding directions thereof were the same, and fig. 6 shows a circuit configuration in the following case: (1) three layers are connected in series, and a single-phase alternating current power supply (frequency 800 Hz; test No.1, FIG. 6(1)) is connected to a winding start portion of the first coil layer and a winding end portion of the third coil layer; (2) three-phase AC power supplies (frequency 800 Hz; test No.2, FIG. 6(2)) were connected to the three layers, respectively, in the manner described above.

At this time, as shown in table 1 below, in the case of test No.1, the power factor was 0.020, and in the case of test No.2, the power factor of the coil layer of the first layer was 0.151, the power factor of the coil layer of the second layer was 0.153, and the power factor of the coil layer of the third layer was 0.060. In this way, it is considered that in the case of fig. 6(2), since the magnetic fluxes generated in the respective conductor tube layers cancel each other out, the voltage drop can be suppressed, and the power factor can be improved. In addition, in the case of the ac voltage converted to the commercial frequency of 60Hz, the power factor of the coil layer of the first layer was 0.898, the power factor of the coil layer of the second layer was 0.900, the power factor of the coil layer of the third layer was 0.627, and the average power factor of each layer was 0.836 with respect to the power factor of test No.1, and in the case of test No. 2. In a fluid heating apparatus having a large power, since a three-phase ac power supply is generally used, as described above, the power factor in the case of using a three-phase ac power supply can be greatly improved, and a significant effect is also obtained in terms of improvement in the efficiency of the apparatus.

TABLE 1

According to the fluid heating apparatus 100 of the present embodiment configured as described above, the three-phase ac power supply 4 is connected so that the resistance values of the respective conductor tube layers 3a, 3b, and 3c are substantially equal and the magnetic fluxes generated in the respective three conductor tube layers 3a, 3b, and 3c are entirely cancelled out, so that the reactance generated in the respective conductor tube layers 3a, 3b, and 3c can be reduced, and the power factor can be improved. The equipment efficiency of the fluid heating apparatus 100 can be improved.

(second embodiment)

A second embodiment of the present invention will be explained below.

The fluid heating apparatus 100 of the present embodiment includes a fluid heating section 3 including one conductor tube 2 or a plurality of conductor tubes 2 electrically connected to each other.

As shown in fig. 7 to 10, the fluid heating section 3 may have various configurations.

The fluid heating section 3 shown in fig. 7 is composed of two conductive pipes 2 electrically connected by an ac circuit including an ac power supply 4, and an ac voltage is applied from the ac power supply 4 to both end portions of an even number (2 in the present embodiment) of dividing elements 3a and 3b formed by equally dividing the impedance value of the entire fluid heating section 3 into even number parts.

Each of the dividing elements 3a and 3b is a conductor tube layer formed by spirally winding a conductor tube 2 having fluid inlets and outlets 2Px and 2Py at both ends thereof for allowing a fluid to be heated to flow in and out. The number of windings, the tube length, the tube diameter, the wall thickness, the winding diameter, and the winding height are adjusted so that the impedance values of the two conductor tube layers 3a and 3b as the two dividing elements are substantially equal to each other. In the present embodiment, the pipe diameter, the wall thickness, the number of windings, and the like of the conductor pipes 2 constituting the respective conductor pipe layers 3a, 3b are made the same.

Furthermore, the conductor tube 2 is insulated on each turn with an insulation or a gap. For example, it is conceivable to use the conductor tube 2 that is subjected to an insulating process such as providing an insulating layer on the outer circumferential surface. Or each plurality of turns can be divided into one group, and the groups are insulated. The number of groups is determined by the value of the current flowing through the conductor tube 2.

The two conductor tube layers 3a and 3b are arranged in 2 layers so that the winding directions thereof are opposite to each other, and are arranged concentrically. In the case where the number of conductor tube layers is an even number of 4 or more, the conductor tube layers are arranged concentrically such that the winding directions of adjacent conductor tube layers are opposite to each other. Here, it is preferable that the magnetic substance for a magnetic path is provided in at least one of the winding core hollow portion of the inner conductor tube layer 3a and the outer side of the outer conductor tube layer 3 b.

In the fluid heating section 3 configured as described above, the fluid inlets and outlets 2Px and 2Py of the conductor tubes 2 constituting the respective conductor tube layers 3a and 3b are located on one end side (upper end side in fig. 7) and the other end side (lower end side in fig. 7). The fluid inlets and outlets 2Px and 2Py have flange portions for connecting external pipes.

In the fluid heating section 3, a voltage of one of positive and negative polarities of an ac voltage (a positive voltage in fig. 7) is applied to one end side (an upper end side in fig. 7) of each of the conductive tube layers 3a and 3b, and a voltage of the other of the positive and negative polarities of the ac voltage (a negative voltage in fig. 7) is applied to the other end side (a lower end side in fig. 7) of each of the conductive tube layers 3a and 3 b.

That is, a terminal (not shown) for applying an ac voltage of one polarity from the ac power source 4 is connected to one end portion of the conductive pipe 2 constituting the conductive pipe layers 3a and 3b, which constitutes the fluid inlet/outlet 2Px on one end side, or to the vicinity thereof. A terminal (not shown) for applying a voltage of the other polarity of the ac voltage from the ac power supply 4 is connected to the other end of the conductive pipe 2 constituting the conductive pipe layers 3a and 3b, which constitutes the fluid inlet/outlet 2Py on the other end side, or to the vicinity thereof.

As described above, when an ac voltage is applied to the respective conductive tube layers 3a and 3b, the directions of currents flowing in the respective conductive tube layers 3a and 3b are opposite to each other, and the directions of magnetic fluxes generated when current is applied to one conductive tube layer 3a and the directions of magnetic fluxes generated when current is applied to the other conductive tube layer 3b are opposite to each other, and cancel each other out.

The fluid heating section 3 shown in fig. 8 is the same as the fluid heating section 3 shown in fig. 7 and the like in terms of the structure of the conductive tube layers 3a and 3b as two dividing elements, but the winding direction of the conductive tube layers 3a and 3b and the method of applying an ac voltage are different.

That is, the two conductor tube layers 3a and 3b are arranged in two layers so that the winding directions thereof are the same direction, and are arranged in concentric circles. In addition, when the number of conductor tube layers is an even number of 4 or more, the conductor tube layers are also arranged in a concentric circle so that the winding directions thereof are the same.

In the fluid heating section 3 configured as described above, a voltage of one of the positive and negative polarities of the ac voltage (positive voltage in fig. 8) is applied to one end side of one of the two conductive tube layers 3a and 3b, and a voltage of the other of the positive and negative polarities of the ac voltage (negative voltage in fig. 8) is applied to the other end side of the one conductive tube layer 3 a. Further, a voltage of one of positive and negative polarities of the alternating voltage (positive voltage in fig. 8) is applied to the other end side of the other conductive tube layer 3b of the two conductive tube layers 3a and 3b, and a voltage of the other of positive and negative polarities of the alternating voltage (negative voltage in fig. 8) is applied to the one end side of the other conductive tube layer 3 b. That is, a voltage of the same polarity is applied to one end side of the one conductive tube layer 3a and the other end side of the other conductive tube layer 3b, and a voltage of the same polarity is applied to the other end side of the one conductive tube layer 3a and the one end side of the other conductive tube layer 3 b.

That is, a terminal (not shown) for applying an ac voltage of one polarity from the ac power source 4 is connected to one end portion or its vicinity of the fluid inlet/outlet 2Px forming one end side of the conductor tube 2 constituting the one conductor tube layer 3a, and a terminal (not shown) for applying an ac voltage of the other polarity from the ac power source 4 is connected to the other end portion or its vicinity of the fluid inlet/outlet 2Py forming the other end side of the conductor tube 2 constituting the one conductor tube layer 3 a. A terminal (not shown) for applying an ac voltage of one polarity from the ac power source 4 is connected to the other end portion of the conductive tube 2 constituting the other conductive tube layer 3b constituting the fluid inlet/outlet 2Py on the other end side or its vicinity, and a terminal (not shown) for applying an ac voltage of the other polarity from the ac power source 4 is connected to one end portion of the conductive tube 2 constituting the other conductive tube layer 3b constituting the fluid inlet/outlet 2Px on one end side or its vicinity.

By applying an ac voltage to the respective conductive tube layers 3a and 3b in this manner, the directions of currents flowing through the respective conductive tube layers 3a and 3b are opposite to each other, and magnetic fluxes generated when current is applied to one conductive tube layer 3a and magnetic fluxes generated when current is applied to the other conductive tube layer 3b are opposite to each other and cancel each other out.

The fluid heating section 3 shown in fig. 9 is constituted by one conductor tube 2 electrically connected by an ac circuit including an ac power supply 4, and an ac voltage is applied from the ac power supply 4 to both end portions of an even number (2 in the present embodiment) of the dividing elements 3a and 3b formed by equally dividing the impedance value of the entire fluid heating section 3 into even number parts.

The two dividing elements 3a, 3b are formed by an inner conductor tube layer 3a and an outer conductor tube layer 3b, the inner conductor tube layer 3a winds a conductor tube 2 in a spiral shape from one end side to the other end side, the outer conductor tube layer 3b is connected to the other end of the conductor tube layer 3a, and the conductor tube is wound in a spiral shape from the other end side to one end side in the same direction as the winding direction of the inner conductor tube layer 3 a. The resistance values of these conductor tube layers 3a, 3b are substantially equal. In the present embodiment, the number of windings and the like of the conductor tube layers 3a and 3b are made the same.

In this way, the winding directions are aligned in the same direction, and the 2 layers are connected into a concentric circle, and 2 conductor tube layers 3a and 3b are formed by winding 2 layers. In other words, the fluid heating portion configured as described above is formed by integrally and continuously connecting the two conductor tube layers 3a and 3 b. In the case where the number of conductor tube layers is an even number of 4 or more, one conductor tube 2 is continuously wound in a concentric circle from one end side to the other end side and then from the other end side to the one end side with the winding direction being the same.

In the fluid heating section 3 configured as described above, the two fluid inlets and outlets 2Px and 2Py are located on one end side (upper end side in fig. 9) regardless of the number of conductor tube layers.

In the fluid heating section 3, a voltage of one of positive and negative polarities of an ac voltage (a positive voltage in fig. 9) is applied to one end side (an upper end side in fig. 9) of each of the conductor tube layers 3a and 3b, and a voltage of the other of the positive and negative polarities of the ac voltage (a negative voltage in fig. 9) is applied to the other end side of each of the conductor tube layers 3a and 3b by connecting the folded sections of each of the conductor tube layers 3a and 3b, that is, an intermediate position between two fluid inlets and outlets. In this way, a common voltage is applied to the adjacent ends (portions divided into the dividing elements) of the two conductor tube layers 3a and 3 b.

That is, a terminal (not shown) for applying a voltage of one polarity of the ac voltage from the ac power source 4 is connected to an end portion of the conductor tube 2 constituting each of the conductor tube layers 3a and 3b constituting one of the fluid inlet and outlet 2Px or the vicinity thereof, and a terminal (not shown) for applying a voltage of one polarity of the ac voltage from the ac power source 4 is connected to an end portion of the conductor tube 2 constituting each of the conductor tube layers 3a and 3b constituting the other of the fluid inlet and outlet 2Py or the vicinity thereof. Further, a terminal (not shown) for applying an ac voltage of the other polarity from the ac power supply 4 is connected to the other end of each of the conductor tube layers 3a and 3b at the folded portion connected to the conductor tube layers 3a and 3 b. The connection piece 31 in fig. 9 is provided at the folded-back portion (intermediate position) and connects the connection terminal of the ac power supply 4.

By applying an ac voltage to the respective conductive tube layers in this way, the directions of currents flowing through the respective conductive tube layers 3a and 3b are opposite to each other, and magnetic fluxes generated when current is applied to one conductive tube layer 3a and magnetic fluxes generated when current is applied to the other conductive tube layer 3b are opposite to each other and cancel each other out.

The fluid heating section 3 shown in fig. 10 has the same configuration of the conductive tube layers 3a and 3b as the two dividing elements as the fluid heating section 3 shown in fig. 7, but differs in the winding direction, the connection method, and the method of applying an ac voltage for the conductive tube layers 3a and 3 b.

That is, the two conductor tube layers 3a and 3b are arranged in two layers so that the winding directions thereof are the same direction, are arranged concentrically, and are electrically connected in series to the ac power supply 4. Specifically, as shown in fig. 10, the other end sides of the conductor tube layers 3a and 3b are connected by the conductive member 5 to short-circuit them, thereby electrically connecting the other end of the one conductor tube layer 3a and the other end of the other conductor tube layer 3 b. In the case where the number of conductor tube layers is an even number of 4 or more, the conductor tube layers are connected in series by electrically connecting one end side or the other end side of the adjacent conductor tube layers.

In the fluid heating section 3, a voltage of one of positive and negative polarities of an ac voltage (positive voltage in fig. 10) is applied to one end side of the two conductive tube layers 3a and 3b connected in series, that is, one end side of the one conductive tube layer 3a, and a voltage of the other of positive and negative polarities of an ac voltage (negative voltage in fig. 10) is applied to the other end side of the two conductive tube layers 3a and 3b connected in series, that is, one end side of the other conductive tube layer 3 b.

That is, a terminal (not shown) for applying an ac voltage of one polarity to the end portion of the fluid inlet/outlet 2Px on one end side of the conductive tube 2 constituting the one conductive tube layer 3a or the vicinity thereof is connected, and a terminal (not shown) for applying an ac voltage of the other polarity to the end portion of the fluid inlet/outlet 2Px on one end side of the conductive tube 2 constituting the other conductive tube layer 3b or the vicinity thereof is connected.

By applying an ac voltage to the respective conductive tube layers 3a and 3b in this manner, the directions of currents flowing through the respective conductive tube layers 3a and 3b are opposite to each other, and magnetic fluxes generated when current is applied to one conductive tube layer and magnetic fluxes generated when current is applied to the other conductive tube layer are opposite to each other and cancel each other out.

Next, a test for improving the power factor of the fluid heating apparatus 100 configured as described above will be described. In the following experiments, in order to clearly show the tendency of comparison, a single-phase ac power supply having a frequency of 800Hz was used, but in an actual fluid heating apparatus, a single-phase ac power supply having a commercial frequency of 50Hz or 60Hz was used, and the power factor was higher than that shown below.

Fig. 11 shows a circuit configuration in the following case: the cross-sectional area of the handle is 8.042mm²A single-phase AC voltage (frequency 800 Hz; test No.1, FIG. 11(1)) was applied to a coil element formed by spirally winding 60 turns of a copper wire having a diameter of 3.2 mm; and two coil elements each formed by spirally winding 30 turns of the copper wire are arranged in the axial direction, a voltage of one of positive and negative polarities of a single-phase alternating current voltage (frequency 800Hz) is applied to the other end side of one coil element and the one end side of the other coil element, and a single-phase cross is applied to the one end side of the one coil element and the other end side of the other coil elementThe flow voltage is a voltage of the other of the positive and negative polarities (test No.2, FIG. 11 (2)).

At this time, as shown in table 2 below, the power factor was 0.039 in the case of test No.1, and 0.048 in the case of test No.2 at the same power as test No. 1. In this way, in the case of fig. 11(2), since the magnetic fluxes generated in the respective conductor tube layers cancel each other out, it is considered that the voltage drop can be suppressed and the power factor can be improved.

TABLE 2

Test No.	Voltage (V)	Current (A)	Power (W)	Power factor
					1	98.65	35.37	140	0.039
2	39.16	71.03	130	0.048

Fig. 12 shows a circuit configuration in the following case: the cross-sectional area of the handle is 8.042mm²A 3.2 mm-diameter copper wire was spirally wound in 60 turns from one end side to the other end side in the same direction as the winding direction to form a coil layer, and 60 turns were wound from the other end side to the one end side to form a coil layer, and a single-phase ac voltage (frequency 800 Hz; test No.1, fig. 12(1)) was applied to both ends of the 2-layer coil element; and applying a voltage of one of positive and negative polarities of a single-phase alternating current voltage (frequency 800Hz) to one end side of the coil element and applying a voltage of the other of positive and negative polarities of a single-phase alternating current voltage to the other end side of the coil element (test No.2, fig. 12 (2)).

At this time, as shown in table 3 below, the power factor was 0.026 in the case of test No.1, and 0.225 in the case of test No.2 at the same power as test No. 1. In this way, in the case of fig. 12(2), since the magnetic fluxes generated in the respective conductor tube layers cancel each other out, it is considered that the voltage drop can be suppressed and the power factor can be improved. The power factor when the single-phase ac power supply having the commercial frequency of 60Hz was 0.324 in the case of test No.1 and 0.951 in the case of test No. 2.

TABLE 3

Test No.	Voltage (V)	Current (A)	Power (W)	Power factor
					1	192.2	17.04	84	0.026
2	8.26	34.46	64	0.225

Fig. 13 shows a circuit configuration in the following case: the cross-sectional area of the handle is 8.042mm²In a 2-layer coil element in which a coil layer was formed by spirally winding 60 turns of a copper wire having a diameter of 3.2mm from one end side to the other end side and 60 turns from the other end side to the one end side so that the winding direction was the same direction, a voltage of one of positive and negative polarities of a single-phase alternating voltage (frequency 800Hz) was applied to a central position between the one end and the other end of the coil element, and a voltage of the other of positive and negative polarities of the single-phase alternating voltage was applied to the one end side and the other end side of the coil element.

In this case, as shown in table 4 below, the power factor was 0.248 when the power was the same as that of test No.2 shown in fig. 12 (2). In the case of fig. 13, the power factor is improved as compared with the case shown in fig. 12 (2). Further, the power factor when a single-phase alternating-current power supply of a commercial frequency of 60Hz was employed was 0.960.

TABLE 4

Test No.	Voltage (V)	Current (A)	Power (W)	Power factor
					1	3.47	69.6	60	0.248

According to the fluid heating apparatus 100 of the present embodiment configured as described above, since the directions of currents flowing through the plurality of divided elements 3a and 3b formed by equally dividing the impedance value of the fluid heating portion by an even number are opposite to each other, and the entire configurations cancel each other out, a voltage drop due to the inductance of the conductor tube 2 can be suppressed, and the power factor can be improved. The equipment efficiency of the fluid heating apparatus 100 can be improved.

(other modified embodiment)

The present invention is not limited to the embodiments.

For example, although the above embodiment has been described with respect to the case where three conductor tube layers 3a, 3b, and 3c are provided (the case where N is 1), the same applies to the case where N is 2 or more. In this case, any one of three-phase ac power sources is connected to the winding start portion of the conductor tube layer of the N-th (N is 1, 2, … 5) th layer and the winding end portion of the conductor tube layer of the (N +1) th layer, and any one of three-phase ac power sources is connected to the winding end portion of the conductor tube layer of the first layer and the winding start portion of the conductor tube layer of the 3N-th layer, or any one of three-phase ac power sources is connected to the winding end portion of the conductor tube layer of the N-th layer and the winding start portion of the conductor tube layer of the (N +1) th layer, and any one of three-phase ac power sources is connected to the winding start portion of the conductor tube layer of the first layer and the winding end portion of the conductor tube layer of the 3N-th layer.

Fig. 14 shows a wiring diagram of a fluid heating section having 6 (N: 2) conductor tube layers. Fig. 14 shows the following case: a first phase (V phase) of a three-phase alternating current power supply 4 is connected to a winding start part of a first layer of a conductor tube layer and a winding end part of a second layer of the conductor tube layer, a second phase (W phase) of the three-phase alternating current power supply 4 is connected to a winding start part of a second layer of the conductor tube layer and a winding end part of a third layer of the conductor tube layer, a third phase (U phase) of the three-phase alternating current power supply 4 is connected to a winding start part of a third layer of the conductor tube layer and a winding end part of a fourth layer of the conductor tube layer, a first phase (V phase) of the three-phase alternating current power supply 4 is connected to a winding start part of a fourth layer of the conductor tube layer and a winding end part of a fifth layer of the conductor tube layer, a second phase (W phase) of the three-phase alternating current power supply 4 is connected to a winding start part of a fifth layer of the conductor tube layer and an winding end part of a sixth layer of the conductor tube layer, and a third phase (U phase) of the three-phase alternating current power supply 4 is connected to And a winding start of the conductor tube layer of the sixth layer.

As shown in fig. 15, a fluid inlet/outlet 2P may be provided in at least one of the winding start portion and the winding end portion of any of the 3N conductor tube layers. That is, M (M is 2, 3, … 3N) conductor tubes 2 are wound in 1 layer or continuously wound in a plurality of layers to form a 3N-layer conductor tube layer, and the fluid inlet/outlet 2P may be provided at a winding start portion or a winding end portion of the conductor tube layer where both end portions of each conductor tube 2 are opened.

Specifically, fig. 15 (a) shows a case where: in a fluid heating unit having 6 layers of conductor pipes, a first conductor pipe 2 of two conductor pipes 2 is continuously and spirally wound for 4 layers, and a second conductor pipe 2 is continuously and spirally wound for 2 layers, and fluid inlets and outlets 2Px and 2Py are provided at a winding start portion of the first layer and a winding end portion of the fourth layer, and a winding start portion of the fifth layer and a winding end portion of the sixth layer. Thus, since the fluids flow through the respective conductive pipes 2, it is possible to heat at most two fluids at the same time.

Further, fig. 15 (B) shows a case where: in a fluid heating section having 6 conductor layers, a first conductor tube 2 of 3 conductor tubes 2 is continuously and spirally wound in three layers, a second conductor tube 2 is continuously and spirally wound in 2 layers, and a third conductor tube 2 is continuously and spirally wound in 1 layer, and fluid inlets and outlets 2Px and 2Py are provided at a winding start portion of the first layer and a winding end portion of the third layer, a winding start portion of the fourth layer and a winding end portion of the fifth layer, and a winding start portion and a winding end portion of the sixth layer. Thus, since the fluids flow through the respective conductive pipes 2, it is possible to simultaneously heat up at most three kinds of fluids.

That is, by variously setting the number of the conductor pipes to be wound and the number of the layers to be wound around each conductor pipe, the fluid inlet/outlet 2P can be provided at least at one of the winding start portion and the winding end portion of any layer.

In the above embodiment, the fluid inlet and outlet are formed by openings at both ends of the conductor tube, but the fluid inlet and outlet may be formed by forming openings in the side wall of the conductor tube. In this way, in the plurality of conductor layers formed by winding a single conductor tube in a multilayer manner, the fluid inlet and outlet can be provided at the winding start portion or the winding end portion of the conductor tube layer excluding the winding start portion and the winding end portion where both end portions of the conductor tube are open.

As shown in fig. 16, when the conductor tube layers 3a, 3b, and 3c connecting the phases of the three-phase ac power supply 4 are electrically insulated from each other as in the fluid heating unit 3 shown in fig. 4, a current control device 6 for individually controlling the phases of the three-phase ac power supply may be provided. The current control device 6 is configured by, for example, a thyristor, and individually controls the currents flowing through the respective conductive tube layers 3a, 3b, and 3c by individually controlling the currents of the respective phases. This allows the temperature of each conductor layer connected to each phase to be controlled independently.

For example, in the above embodiment, the dividing member is formed by winding a conductor pipe in a spiral shape, but the fluid heating section may be formed by a conductor pipe having a straight pipe shape, and the dividing member may have a straight pipe shape. In this case, the two fluid ports 2P are located at the axial ends of the conductor tube 2, respectively.

Fig. 17 shows a test for improving the power factor of a fluid heating apparatus having a fluid heating portion constituted by such straight tube-shaped dividing members.

Fig. 17 shows a circuit configuration in the following case: a single-phase AC voltage (frequency 800 Hz; test No.1, FIG. 17(1)) was applied to both ends of a stainless steel tube having a diameter of 34mm, a tube length of 2200mm and a tube wall thickness of 1.65 mm; and dividing the stainless steel tube into two halves, applying a voltage of one of positive and negative polarities of a single-phase alternating voltage (frequency 800Hz) to both ends of the stainless steel tube, and applying a voltage of the other of positive and negative polarities of the single-phase alternating voltage to a middle position (a boundary position between two dividing elements) of the stainless steel tube (test No.2, fig. 17 (2)).

At this time, as shown in table 5 below, the power factor was 0.1715 in the case of test No.1, and 0.1985 in the case of test No.2 at the same power as test No. 1. In this way, in the case of fig. 17(2), since the magnetic fluxes generated in the two divided elements cancel each other out, it is considered that the voltage drop can be suppressed and the power factor can be improved.

TABLE 5

Test No.	Voltage (V)	Current (A)	Power (W)	Power factor
					1	2.97	66.75	34.0	0.1715
2	1.593	131.58	41.6	0.1985

As shown in tables 6 to 8 below, the superheated steam or the like generated by the fluid heating apparatus 100 according to the present embodiment can be used in various application examples (applications). That is, the fluid heating apparatus 100 according to the present embodiment can be used by being incorporated into equipment corresponding to the application examples shown in tables 6 to 8.

In addition, the present invention is not limited to the above embodiment, and various modifications may be made without departing from the spirit of the present invention.

TABLE 6

TABLE 7

TABLE 8

Claims

1. A fluid heating apparatus for heating a fluid flowing in a conductor pipe having the fluid flowing therein by applying an alternating voltage to the conductor pipe and heating the conductor pipe by energization,

comprises a fluid heating section composed of a single conductor tube or a plurality of conductor tubes electrically connected to each other, wherein an alternating voltage is applied from an alternating current power supply to both end portions of an even number of dividing elements formed by equally dividing an impedance value of the fluid heating section into even number parts,

the even number of dividing elements are even number of conductor tube layers which are constituted by winding the conductor tubes in a spiral shape and are arranged in concentric circles with each other,

the resistance values of the even number of conductor tube layers are equal to each other,

and applying alternating voltage to two end parts of the even number of conductor tube layers to enable the directions of currents flowing in the conductor tube layers to be opposite, so that magnetic fluxes generated by the even number of conductor tube layers are offset with each other as a whole.

2. Fluid heating device according to claim 1,

the even number of conductor tube layers are arranged such that the winding directions of adjacent conductor tube layers are opposite,

a voltage of one of positive and negative polarities of an alternating voltage is applied to one end side of each of the conductive tube layers, and a voltage of the other of the positive and negative polarities of the alternating voltage is applied to the other end side of each of the conductive tube layers.

3. Fluid heating device according to claim 1,

the even number of conductor tube layers are configured to make the winding directions of the adjacent conductor tube layers in the same direction,

one end side of one of the adjacent conductor tube layers is located on the same side as one end side of the other conductor tube layer, the other end side of the one conductor tube layer is located on the same side as the other end side of the other conductor tube layer,

applying a voltage of the same one of positive and negative polarities of an alternating voltage to one end side of the one conductive tube layer and the other end side of the other conductive tube layer,

and applying a voltage with the same polarity of the other of the positive and negative polarities of the alternating voltage to the other end side of the one conductor tube layer and the one end side of the other conductor tube layer.

4. Fluid heating device according to claim 1,

the even number of conductor tube layers are continuously wound in a mode that the winding direction of the adjacent conductor tube layers is the same,

5. The fluid heating apparatus according to claim 1, wherein a magnetic body for a magnetic circuit is provided on at least one of a core hollow portion of the conductor tube layer wound in a spiral shape and an outer side of the conductor tube layer.