JPH09178103A - Induction type super heated steam generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain superheated steam stably from water by a method wherein a steam separation container is connected between a heat exchanger tube having first and second coils and both the coils and shortcircuiting members are provided to electromagnetically isolate both the coils and the steam separation container by shortcircuiting the heat exchanger tube. SOLUTION: A water supply means 8 is driven by a controller 20 to introduce water to a first coil part 5 and a current is fed to an induction coil 2 from an AC power source. A magnetic flux generated in the induction coil 2 passes through the first and second coil parts 5 and 6 by way of a core member 1. An eddy current is caused in the surface of the coils by electromagnetic induction with the first and second coil parts 5 and 6 to generate an induction electromotive force. The first and second coil parts 5 and 6 form a closed electric circuit together with first and second shortcircuiting members 11 and 12. In this manner, the first and second coil parts 5 and 6 themselves function as heating body. This achieves higher efficiency of heat transfer and facilitates the separation of steam from hot water with the steam separation container 10 arranged on the downstream side of the first coil part 5 thereby enabling stable acquirement of superheated steam.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an induction heating type superheated steam generator in which a heat transfer tube is wound in a coil shape, and water is introduced into the heat transfer tube and induction heating is performed to generate superheated steam. .

[0002]

2. Description of the Related Art In recent years, an induction heating method is becoming widespread as a clean heating method that does not involve combustion. By utilizing this heating method, household cookware and hot water supply equipment (especially hot water supply equipment for baths) are used. Etc. have been proposed and are actually used.

In an apparatus utilizing the above heating system,
One that heats the fluid flowing in the pipeline is, for example, a configuration in which a pipeline made of a conductive material is arranged at the center of the induction coil, and the induction coil surrounds this pipeline in a substantially coaxial shape. An eddy current is generated in the pipe by passing an alternating current through the induction coil, and heating is performed by Joule heat generated by the eddy current.

In such a heating device, in which the pipe is coiled in order to increase the area of the heating portion, both the coiled pipe and the induction coil are connected to the core member. In the closed circuit formed by the coiled pipe and this member, the pipes are arranged in an interlinking state, and the pipe is short-circuited between the inflow side part and the outflow side part of the coiled part by a conductive member. There is also a structure in which the Joule heat generated by the induced current is used for heating by causing an induced current to flow. With this structure, it is possible to effectively use water that does not undergo phase change, such as heating water to obtain hot water or heating steam to obtain superheated steam. However, the so-called steam boiler, which involves a phase change from liquid to gas, cannot be applied because of the following inconveniences. That is, in such an electromagnetic heating system, the entire heat transfer surface of the heat transfer tube is heated more uniformly than a general steam generator using a heat source such as a burner, so that the entire heat transfer tube is covered. At the same time, bubbles due to evaporation and bubbles due to expansion of air in water are generated. These bubbles will push the bubbles above them further, so that water will be ejected from the outflow side of the pipe. Therefore, with the conventional structure, it is difficult to obtain a steam generator that can stably supply steam with a high degree of dryness from the start-up. Moreover, in the configuration of one heating pipe system and one power source, superheated steam from water The superheated steam generator which obtains is not achieved. In particular, superheated steam tends to be heavily used for research equipment and applications such as cleaning and sterilization. The superheated steam generator for such applications is required to be compact and have stable performance. It was not possible to obtain a superheated steam generator satisfying this requirement only by electromagnetically heating the.

[0005]

The problem to be solved by the present invention is to provide an induction heating type superheated steam evaporator which can stably obtain superheated steam from water.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems and includes an induction coil arranged in a linked state with a core member, and an induction coil arranged in a linked state with the core member. A heat transfer tube having a first coil portion and a second coil portion, a steam separation container connected between an upstream side of the first coil portion and a downstream side of the second coil portion, and the heat transfer tube. A short circuit member that electromagnetically isolates the first and second coil units and the water-water separation container by short-circuiting is provided as a first feature, and the short circuit member is A first short-circuit member connected between an upstream side of the first coil portion and a downstream side of the second coil portion, and an upstream side of a connection portion of the first coil portion with the steam-water separation container and the second coil Connection between the steam water separation container and the downstream side of the connection part A second characteristic is that it is a second short-circuit member, and the short-circuit member is provided between an upstream side of the first coil portion and an upstream side of a connection portion of the first coil portion with the steam separation container. The first short-circuit member connected and the second
A third characteristic is that the second short-circuit member is connected between the downstream side of the coil portion and the downstream side of the connection portion of the second coil portion with the steam-water separation container. Furthermore,
The ratio of the amount of heat generated by the first coil portion to the amount of heat generated by the second coil portion is approximately equal to the ratio between the amount of energy required to make water into saturated steam and the amount of energy required to make saturated steam into superheated steam. The fourth feature is that the above-mentioned process is performed, and a steam separation plate is provided in the steam separation container.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION A basic embodiment of the present invention is configured as a superheated steam generator provided with a monotube type heat transfer tube. That is, in the superheated steam generator according to the present invention, the heat transfer tube for introducing the fluid is formed into a coil shape, and this coiled portion is used as a heat generating portion. Therefore, this configuration can set a large heat transfer area per volume. The coiled portion is arranged so as to interlink with the core member. An induction coil is arranged in the core member in a state of being linked to the core member, and therefore,
The coil-shaped portion and the induction coil are magnetically connected via the core member. At this time, both the induction coil and the coil-shaped portion may be in an interlinking state with the core member, but they are preferably arranged substantially coaxially in order to effectively use the magnetic flux generated by the induction coil.

The coiled portion is composed of a first coil portion on the upstream side and a second coil portion on the downstream side, and the heat generation ratio of the first coil portion and the second coil portion is water. The ratio of the amount of energy required to make saturated steam and the amount of energy necessary to make saturated steam superheated steam is made to substantially match. The adjustment of the heat generation amount of each of the first and second coil parts is performed by adjusting the inner and outer diameters of the tubes of the first coil part and the second coil part, the number of coil turns, dimensional elements such as the coil diameter, and the electrical resistance value. It is adjusted by selecting an appropriate material such as physical properties. If the tube diameter, the material, and the coil diameter are the same, the adjustment may be made according to the winding ratio. For example, the energy required to turn water (saturated water) at room temperature (about 20 ° C.) into saturated steam in the pressure range of 1 to 5 kg / cm ² G is approximately 646.4.
~ 658.0 kcal / kg, this saturated steam is 260
The energy required to turn into superheated steam at ° C is approximately 97 to 83 kcal / kg. Therefore, the amount of energy required to turn water into saturated steam is about 6 to 8 times the amount of energy required to turn saturated steam into superheated steam. Therefore, the ratio of the number of turns is about 6 to 8 times. Becomes

Further, a steam separation container is connected between the first coil portion and the second coil portion. This air / water separation container is for providing a boundary between the liquid phase portion and the gas phase portion between the first coil portion and the second coil portion, and therefore, the inside of the first coil portion is saturated by heating of water. The second to produce steam
The coil section generates superheated steam by heating saturated steam.

The first and second coil portions are short-circuited by a conductive member at locations other than the respective winding portions, thereby electromagnetically isolating the water / water separation container. The short-circuit member used at this time is between the upstream side of the first coil portion and the downstream side of the second coil portion, and the upstream side of the connection portion of the first coil portion with the steam separation container and the second coil portion. It is connected to the downstream side of the connection part with the air / water separation container in. With this configuration, the air-water separation container is isolated from the electrically closed circuit formed by the first and second coil parts and each short-circuit member, and does not generate an induction current so that it does not generate heat and thus becomes an overheating part. There is no. At this time, it is preferable in terms of thermal efficiency that each short-circuit member is brought as close as possible to each coil portion to reduce the electric resistance in the closed circuit. Further, each short-circuit member is provided between the upstream side of the first coil portion and the upstream side of the connection portion of the first coil portion with the water-water separation container, and between the downstream side of the second coil portion and the air side of the second coil portion. The steam-water separation container can be configured so as not to be affected by the induced current in each coil by connecting the water-separation container and the downstream side of the connection part.
In this case, the short-circuit member arranged between both ends of the first coil portion may be a conduit for communicating the both ends, and in this case, the energy consumed in the short-circuit member should also be used for steam generation. You can

When an alternating current is applied to the induction coil, the induction current flows in the closed circuit composed of the first and second coil parts and the short-circuit member (first and second short-circuit member). Therefore, the first and second coil parts are heated by the eddy current and the Joule heat generated by the induced current. That is, since a transformer is formed by the induction coil and the first and second coil portions, a large current flows through the first and second coil portions when an AC power source is connected to the induction coil. As a result, Joule heat is generated in each coil and heating is performed efficiently. Further, by using each coil portion as a heating portion in this manner, a heat transfer area (heat generation area) can be widened, and heat exchange can be efficiently performed. In this heating state, water evaporates inside the first coil portion to become saturated steam and flows into the steam-water separation container, and inside the second coil portion, saturated steam from the steam-water separation container. Is further heated to become superheated steam. Also, when the short-circuit member arranged between both ends of the first coil portion is a connecting pipe, the water in the connecting pipe is also heated by Joule heat due to the induced current to become steam, and the water inside the water-water separation container is formed. Flow into.

Here, as the core member, for example, a laminate of silicon steel sheets or a laminate of amorphous metal films, which is usually used as an iron core of a transformer, can be used. As the conductive wire material forming the induction coil, for example, a copper wire covered and insulated with glass fiber can be used.
Next, the pipe may be made of any material as long as it allows an electric current to flow, for example, a copper pipe, an iron (including steel) pipe, a stainless pipe, or the like. Also, the connecting pipe functioning as a short-circuit member may be made of any material as long as it can pass an electric current, like the above-mentioned pipe, and is, for example, a copper pipe, an iron (including steel) pipe, a stainless pipe, or the like. .

In this way, the first and second coil portions are formed in an appropriate ratio, and the vapor-water separation container is connected between them, so that each coil portion is independent of the liquid phase portion and the vapor phase portion. Since it is possible to easily separate the steam and the hot water in the steam-water separation container and introduce only the steam into the second coil portion, the superheated steam can be stably provided. Further, when the both ends of the first coil portion are connected by the connecting pipe, the connecting pipe functions as the above-described downfall pipe, so that the liquid droplets flowing out together with the steam from the first coil portion are coiled. Since it can be refluxed to the upstream side of the shaped portion, it is possible to stably supply the vapor having a high degree of dryness and heat the feed water to effectively use the heat.

Furthermore, in a preferred embodiment of the present invention, the water / water separation plate is provided in the water / water separation container, whereby the water in the first coil portion is boiled and is heated as bubbles together with bubbles. Even if it spouts, it is blocked by this steam separation plate and prevented from flowing into the second coil portion on the superheated steam generation side.

The control of the superheated steam generator is performed as follows, for example. First, regarding water supply control, the temperature on the downstream side of the first coil portion is detected, and continuous flow rate control is performed so that this temperature falls within a predetermined set temperature or set temperature range. Preferably, a temperature sensor is provided on the surface on the downstream side of the first coil section, the heating degree of the first coil section is detected by the output from the temperature sensor, and based on the difference between the heating degree and the set temperature. , A pulse type electromagnetic pump, etc., with variable flow rate water supply pump. Next, the induction heating control is performed by the first control as described above.
By providing a sensor for detecting the temperature downstream of the coil portion, the temperature of the first coil portion is controlled to a predetermined temperature by turning on / off the power supply to the induction coil and controlling the amount of power supply according to the change in the temperature. Or, it is controlled to be within the temperature range. That is, on the downstream side of the first coil portion, the state of heat transfer from the pipe to the internal fluid differs depending on whether the state of the internal water is liquid (water, hot water) or gas (steam), and the temperature changes. Therefore, by detecting this temperature, overheating can be prevented and stable control can be performed. Therefore, it is possible to easily adjust the amount of superheated steam generated and the temperature by combining the control of the induction heating amount and the control of the feed water.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. Incidentally, FIG. 1 is a side view showing a specific embodiment of the induction heating steam generator according to the present invention.
FIG. 2 is an explanatory plan view of FIG. In the drawing, the core member (1) has an oval shape.
In order to reduce its own eddy current loss, thin steel plates are laminated with an insulator interposed therebetween, and the thin steel plates also use a silicon steel plate or the like to reduce the specific resistance. The thickness of the core member is set to a magnetic flux density that does not reach magnetic saturation, and is preferably set to a cross-sectional area such that it is maintained at 20,000 Gauss or less. The induction coil (2) is arranged in a chain with one linear portion of the core member (1). The induction coil (2) is formed by winding a copper wire coated and insulated with glass fiber a predetermined number of times. The induction coil (2) is controlled in current value and frequency supplied by an appropriate power supply circuit. In this embodiment, a general commercial AC power supply (hereinafter, simply referred to as AC power supply) (3 ) Is connected.

A heat transfer tube (4) made of a conductive material is wound around the outer circumference of the induction coil (2) in the form of a coil.
The coil parts (5) and (6) are arranged substantially coaxially. Therefore,
These first and second coil parts (5) and (6) are also the induction coil.
Similar to (2), the core member (1) is linked to the core member (1), and the induction coil (2) and the first and second coil portions (5),
(6) is in a state of being magnetically coupled through the core member (1). The first coil portion on the upstream side (the lower side in FIG. 1)
The turn ratio in (5) and the second coil section (6) on the downstream side (upper side in Fig. 1) is required to turn the saturated steam into superheated steam. It is set in consideration of the ratio with the amount of energy. In this embodiment, since the pipe diameter, material and coil diameter of the first and second coil portions (5) and (6) are the same, It is adjusted.
For example, with this superheated steam generator, pressure of 1-5 kg /
In the case of obtaining superheated steam at 260 ° C in the cm ² G range,
The ratio of the number of turns of the first coil portion (5) (or the ratio of electrical resistance) is about 6 to 8 times that of the second coil portion (6). A water supply means is provided at an inflow side portion (7) upstream (lower side in FIG. 1) of the winding portion of the first coil portion (5) around the core member (1).
(8) is connected, and water is introduced into the inside of the first coil part (5) by this water supply means (8). In addition, this water supply means
As (8), a pump capable of continuously adjusting the flow rate, for example, a pulse type electromagnetic pump is used. On the other hand, a cooker, a heating device, a sterilizer, etc. are provided at the outflow side portion (9) on the downstream side (upper side in FIG. 1) of the winding portion of the second coil portion (6) around the core member (1). The superheated steam using device (not shown) is connected.

Further, between the first coil portion (5) and the second coil portion (6), that is, the core member of the first coil portion (5).
The downstream side (upper side in FIG. 1) of the winding portion around (1) and the upstream side (lower side in FIG. 1) than the winding portion around the core member (1) of the second coil portion (6). An air / water separation container (10) is connected between them. With the above configuration, the induction heating steam generator of the present invention is configured as a steam generator including a monotube type heat transfer tube.

Further, the inflow side portion of the first coil portion (5)
A first short-circuit member (11) made of a conductive member is mechanically and electrically connected between (7) and the outflow side portion (9) of the second coil portion (6). Between the upstream side of the connection portion of the first coil portion (5) with the steam / water separation container (10) and the downstream side of the connection portion of the second coil portion (6) with the steam / water separation container (10). Similarly, a second short-circuit member (12) made of a conductive member is mechanically and electrically connected between the two. With this configuration, an electrically closed circuit connected to the first coil portion (5), the second short-circuit member (12), the second coil portion (6), the first short-circuit member (11), and the first coil portion (5) is formed. Formed, the steam separator (10) is electrically isolated from them. The first coil portion
(5) When a screw-type pipe connecting member is used at the connection point between the second coil part (12) and the water / water separation container (10), the threaded part should be insulated with packing, sealing tape, etc. By interposing a conductive material, the electrical isolation of the steam-water separation container (10) becomes more reliable.

The control device (20) in the induction heating type superheated steam generator uses the induction signal based on the detection signal from the temperature sensor (21) provided on the downstream side of the first coil section (5). The power supply control means (22) connected between the coil (2) and the AC power supply (3) and the water supply means (8) are controlled. That is, in the control device (20) of this embodiment, the temperature of the heat transfer tube (4) at the position of the downstream side of the first coil portion (5) (upstream side to the steam separation container (10)) is set to the temperature. Sensor (21)
Monitored by the first coil unit according to this temperature change
The heating condition of (5) is detected, and based on the difference between this heating condition and the set temperature, the water supply means is set so that the output from the temperature sensor (21) is within a predetermined set temperature or set temperature range.
By continuously controlling the flow rate of (8) and controlling the power supply control means (22) according to the change of the temperature, on / off of the energization to the induction coil (2) and further the energization amount can be controlled. The temperature of the first coil portion (5) is adjusted and controlled so as to be within a predetermined set temperature or set temperature range.

In the induction heating type superheated steam generator having the above construction, the water supply means (8) is driven by the control device (20) to introduce water into the first coil portion (5),
An AC current from the AC power supply (3) is supplied to the induction coil (2) by a power supply control means (22). At this time, the water level is controlled so as to be located inside the steam separation container (10) or near the upper end of the first coil portion (5) below the water level. The magnetic flux generated by the induction coil (2) passes through the core member (1) and the first and second coil portions (5) and (6). In these first and second coil parts (5) and (6),
Electromagnetic induction causes an eddy current on its surface and an induced electromotive force. In addition, the first and second coil portions (5),
Since (6) constitutes an electrically closed circuit together with the first and second short-circuit members (11) and (12), an induced current also flows in this closed circuit due to this induced electromotive force. Therefore,
The electrically closed circuit, that is, the first and second coil parts (5), (6)
Will be heated by the Joule heat due to the induced current, and will also be heated by the Joule heat due to the eddy current. At this time, the turns ratio in the first coil portion (5) and the second coil portion (6) is such that the amount of energy required to turn water into saturated steam and the amount of energy required to turn saturated steam into superheated steam. Since it is set in consideration of the ratio with
Appropriate heating is performed in the first coil section (5) to turn water into saturated steam, and appropriate heating is performed in the second coil section (6) to turn this saturated steam into a predetermined superheated steam. Be done. Therefore, the water supply from the water supply means (8) is heated inside the first coil part (5) to become steam, which is a steam separation container.
It flows into (10). Inside this air / water separation container (10),
Saturated water of the steam stays in the steam-water separation container (10), so that the saturated steam flows into the second coil portion (6). Then, in the second coil portion (6), the saturated steam is further heated and becomes superheated steam, which is supplied from the outflow side portion (9) to the above-mentioned equipment using superheated steam.

As described above, in the present invention, since the first and second coil portions (5) and (6) themselves function as a heating element, the heat transfer efficiency is good, and the power loss is in addition to the reason described below. The heat is transferred to the first coil portion.
By providing the steam-water separation container (10) on the downstream side of (5), it is possible to easily separate steam and hot water in the steam-water separation container (10). The superheated steam can be obtained by providing it to the two coil parts (6).

Further, in this embodiment, by providing the air / water separation plate (13) in the air / water separation container (10) for blocking the opening of the first coil portion (5), the Even if the water in the coil part (5) bumps and is ejected together with steam as hot water, it is blocked by this steam separation plate (13) and prevented from flowing out to the second coil part (6) side. With this configuration, the superheated steam can be supplied more stably.

The connection points of the first and second short-circuit members (11) and (12) are not limited to those in the above-mentioned embodiment, and in short, the water-and-water separation container (10) is the first and second coil parts. It is sufficient if the configuration is not affected by the induced current flowing in (5) and (6). This example will be described with reference to FIGS. Here, FIG.
Is a side view of another embodiment, and FIG. 4 is a plan view of the embodiment shown in FIG. In the embodiment shown in FIGS. 3 and 4, the first short-circuit member (11) is connected to the first coil portion (5).
Mechanically and electrically connected between the inflow side portion (7) of the pipe and the upstream side of the connecting portion of the steam / water separation container (10) in the first coil portion (5), and the second short-circuit member (12) Mechanically and electrically between the outflow side part (9) of the second coil part (6) and the downstream side of the connection part of the steam / water separation container (10) in the second coil part (6). It is connected. With this configuration, the first coil portion (5)
And the first short-circuit member (11), the second coil portion
An independent electric closed circuit can be formed by the (6) and the second coil part (6), and the steam-water separation container (10) is connected to the first and second coil parts (5), (6). It is possible to adopt a configuration that is not affected by the induced current in. In this case, the first
The first short-circuit member (11) arranged between both ends of the coil part (5),
As shown in the figure, the first coil portion (5) may be a conduit for communicating between both ends thereof. In this case, the first short-circuit member (1
The induced current flowing in 1) can also be used for steam generation.

[0025]

As described above, according to the present invention, the first and second coil portions formed by winding the heat transfer tube are electromagnetically coupled to the induction coil, and the first and second coil portions are electrically connected to each other. Since the steam-water separation container is connected to the first coil portion, water can be heated in the first coil portion, and only the steam separated by the steam-water separation container can be heated in the second coil portion to obtain superheated steam. An induction heating type superheated steam generator that can stably obtain superheated steam on a stand can be provided. Furthermore, since the air-water separation container is configured so as not to be affected by the induced current generated in the first and second coils by the first and second short-circuiting members, heat is generated by the induced current. Therefore, the heating for obtaining the superheated steam is performed only by the first and second coil portions, so that the heating can be easily controlled. Moreover, the first
The ratio of the calorific value of the coil part and the second coil part is set to be substantially equal to the ratio of the amount of energy required to turn water into saturated steam and the amount of energy required to turn saturated steam into superheated steam. By doing so, appropriate heating can be performed in each coil portion, so that energy loss can be prevented and efficiency can be improved. Furthermore, by providing a steam separation plate in the steam separation container, by any chance,
Even if the water in the first coil part bumps and is ejected together with bubbles as hot water, it can be blocked by this water-water separation plate and prevented from flowing into the second coil part, so that a stable supply of superheated steam is ensured. Becomes

[Brief description of the drawings]

FIG. 1 is a side view illustrating a specific embodiment of an induction heating type superheated steam generator according to the present invention.

FIG. 2 is an explanatory plan view of the embodiment shown in FIG. 1;

FIG. 3 is a side view of another specific example of the induction heating type superheated steam generator according to the present invention.

4 is an explanatory plan view of the embodiment shown in FIG.

[Explanation of symbols]

 (1) Core member (2) Induction coil (3) AC power supply (4) Heat transfer tube (5) First coil part (6) Second coil part (7) Inflow side part (8) Water supply means (9) Outflow side Part (10) Air-water separation container (11) First short-circuit member (12) Second short-circuit member (13) Water-water separation plate (20) Control device (21) Temperature sensor (22) Power supply control means

Claims (5)

[Claims] 1. An induction coil (2) arranged in an interlinking state with a core member (1), a first coil portion (5) arranged in an interlinking state with the core member (1), and a second coil portion. A heat transfer tube (4) having (6), and a steam separation container (10) connected between the upstream side of the first coil section (5) and the downstream side of the second coil section (6)
By short-circuiting the heat transfer tube (4), the first coil part (5), the second coil part (6) and the water / water separation container (10)
An induction heating type superheated steam generator, comprising: 2. The short-circuit member comprises the first coil portion (5).
Connection between the first short-circuit member (11) connected between the upstream side of the coil and the downstream side of the second coil section (6) and the steam-water separation container (10) in the first coil section (5) Upstream of the section and the second
The induction heating type superheat according to claim 1, which is a second short-circuit member (12) connected between a coil portion (6) and a downstream side of a connection portion with the steam-water separation container (10). Steam generator. 3. The short-circuit member comprises the first coil portion (5).
First short-circuit member (11) connected between the upstream side of the first coil part (5) and the upstream side of the connection part of the steam / water separation container (10) in the first coil part (5), and the second coil part (6 ) And the second side
The induction heating type superheat according to claim 1, which is a second short-circuit member (12) connected between a coil portion (6) and a downstream side of a connection portion with the steam-water separation container (10). Steam generator. 4. The ratio of the calorific value of the first coil section (5) to the second coil section (6) is such that the amount of energy required to make water into saturated steam and the saturated steam to be superheated steam. The induction heating type superheated steam generator according to claim 1, claim 2 or claim 3, wherein the ratio is substantially equal to the amount of energy required for the above. 5. A steam separation plate (1) is provided in the steam separation container (10).
The induction heating type superheated steam generator according to claim 1, claim 2, claim 3, or claim 4, characterized in that 3) is provided.