JP7190627B2 - Superheated steam generator and cooker - Google Patents

Description

TECHNICAL FIELD The present invention relates to a superheated steam generator that generates steam of 100° C. or higher, and a cooker equipped with this superheated steam generator.

As a conventional superheated steam generator, there is one disclosed in Patent Document 1. FIG. 11 is a cross-sectional view of the superheated steam generator described in Patent Document 1. FIG. As shown in FIG. 11, an evaporating heater 32 is embedded in the steam generating vessel 30 of this superheated steam generator, and a superheating heater 33 is positioned higher than the evaporating heater 32 in the steam generating vessel 30 . Buried. A steam generating chamber 31 is provided in the steam generating container 30, and the evaporation heater 32 evaporates water supplied from the water supply port 35 into the steam generating chamber 31 to generate steam. The generated steam b, on the way up in the steam generation chamber 31, comes into contact with the fin group 34 heated by the superheater 33, is superheated by the fin group 34, and flows out of the steam generation container 30 through the steam port 36. released. This configuration eliminates the need for a fan device for supplying the steam b to the superheater 33, thereby simplifying the configuration. Also, the effective area of the cooking chamber in the cooker to which the superheated steam generator is installed is not reduced due to the influence of the fan device.

JP-A-2006-349313

In the superheated steam generator of Patent Document 1, the evaporation heater 32 and the superheater 33 are embedded in the same steam generation container 30, so that the heat of the evaporation heater 32 can be transmitted to the fin group 34. The heat of the evaporative heater 32 can also be used to superheat the steam. The heat of the superheater 33 can also be used to evaporate the water in the steam generation chamber 31 by transferring it to the vicinity of the evaporation heater 32 of the steam generation container 30 . With such a configuration, the surplus heat not used for raising the temperature of the water by the evaporation heater 32, the heat used for evaporation, or the heat for superheating the steam by the superheater 33 is supplied to the other. Heat can be effectively used to achieve more efficient heating.

However, in the superheated steam generator of Patent Document 1, the steam generated by the evaporating heater 32 is superheated by the fin group 34 heated by the superheating heater 33 in the process of rising. In order to secure a sufficient heat area, it is necessary to increase the height dimension of the steam generating vessel 30 . In this case, the distance between the axes of the evaporative heater 32 and the superheating heater 33 increases, and the amount of heat released in the path until the heat of the evaporating heater 32 or the superheating heater 33 is transmitted to the other superheating heater 33 or the evaporating heater 32 increases. , there is a problem that the thermal efficiency is reduced.

According to the present invention, the distance between the axes of the evaporating heater and the superheating heater is shorter than the distance between the axes of the straight parts of the evaporating heater and the distance between the axes of the straight parts of the superheating heater. Provided is a superheated steam generator and a cooker equipped with the superheated steam generator capable of reducing the amount of heat released in a path that transmits heat to a superheater or a path that a superheater transmits to the vicinity of an evaporating heater, thereby improving thermal efficiency. for the purpose.

In order to solve the conventional problems, the superheated steam generator of the present invention includes:
a heating container, a water inlet for supplying water to the heating container, an evaporative heater for heating the heating container to evaporate the water supplied from the water inlet to the heating container, and steam generated by the evaporative heater and a superheater disposed outside the pipe for superheating the steam passing through the pipe by heating the pipe, wherein the evaporative heater and the superheater each have two or more The minimum distance between the axes of the evaporative heater and the superheating heater is the maximum distance between the axes of the straight part of the evaporating heater and the maximum distance between the axes of the straight parts of the superheating heater. It is configured to be shorter than the distance.

As a result, it is possible to provide a superheated steam generator with improved thermal efficiency by reducing the amount of heat released in the path in which the evaporating heater transmits heat to the vicinity of the superheater or in the path in which the superheating heater transmits heat to the vicinity of the evaporating heater.

In the present invention, the distance between the axes of the evaporating heater and the superheating heater is shorter than the distance between the axes of the straight parts of the evaporating heater and the distance between the axes of the straight parts of the superheating heater. The amount of heat radiated in the path through which the heat is transmitted to or through the path through which the overheating heater transmits to the vicinity of the evaporative heater can be reduced, and the thermal efficiency can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS The perspective view of the superheated steam generator in Embodiment 1 of this invention. 1 is an exploded perspective view of a superheated steam generator according to Embodiment 1 of the present invention; External view of the superheated steam generator viewed from the X direction in FIG. External view of the same superheated steam generator viewed from the Y direction in FIG. AA line sectional view in FIG. BB line sectional view in FIG. CC line sectional view in FIG. Schematic diagram of the configuration of an oven equipped with a superheated steam generator according to Embodiment 1 of the present invention A perspective view of a superheated steam generator according to Embodiment 2 of the present invention. An exploded perspective view of a superheated steam generator according to Embodiment 2 of the present invention. Schematic cross-sectional view showing a schematic configuration of a conventional superheated steam generator shown in Patent Document 1

A first invention comprises a heating container, a water supply port for supplying water to the heating container, an evaporation heater for heating the heating container to evaporate the water supplied from the water supply port to the heating container, and a pipe through which steam generated by an evaporative heater passes; and a superheater disposed outside the pipe for superheating the steam passing through the pipe by heating the pipe, wherein the evaporative heater and the superheater each has two or more straight parts, and the minimum distance between the axes of the evaporative heater and the superheater is the maximum distance between the axes of the straight parts of the evaporative heater and the straight part of the superheater The superheated steam generator is configured to be shorter than the maximum distance between the axes of the.

As a result, the distance between the evaporative heater and the superheater is reduced, so that the heat of the evaporative heater is transferred to the vicinity of the superheater, or the heat of the superheater is transferred to the vicinity of the evaporative heater. It is possible to improve the thermal efficiency.

In a second invention, particularly in the first invention, the water supplied from the water supply port moves along the longitudinal direction of the evaporative heater, and the steam generated by the evaporative heater is transferred to the evaporative heater or the superheater. The superheated steam generator is configured to move along the longitudinal direction of the heater.

As a result, it becomes easier to keep the evaporating heater close to the flow path in the heating container where the water moves, and the heat from the evaporating heater can be easily transferred to the water, so that the water can be raised efficiently. Warm and allow to evaporate. Also, in the flow path through which the evaporated steam moves, the evaporative heaters are easily kept close to each other, and the heat of the superheater is easily transferred to the steam, so that the temperature of the steam can be efficiently increased. Further, when the water heated by the evaporation heater evaporates in the middle of the flow path along the evaporation heater, it can be superheated to 100° C. or more in the remaining flow path along the evaporation heater.

In a third invention, in particular, in the first invention, a heat exchange promoting portion is provided in the pipe, and the heat exchange promoting portion is composed of a core rod and a helical body wound around the outer periphery of the core rod. It is a superheated steam generator.

As a result, the steam passing through the pipe moves inside the pipe along the helical body, increasing the contact area between the inner surface of the pipe heated by the superheater and the steam, thereby improving the heat exchange efficiency. can.

A fourth invention is the superheated steam generator according to the first invention, wherein the evaporating heater, the pipe, and the superheating heater are configured to be in close contact with the heating vessel.

As a result, when the heat of the evaporative heater is transferred to the vicinity of the superheater, or when the heat of the superheater is transferred to the vicinity of the evaporative heater, the heat is transferred only to the heating container, enabling rapid heat transfer. Become.

In a fifth aspect, in particular, in the first aspect, a heat transfer section is provided between the pipe and the overheating heater, and an evaporating section composed of the heating vessel, the water supply port, and the evaporating heater; The superheated steam generator is provided with a joint where a superheating section composed of a pipe, the superheater, and the heat transfer section is joined.

As a result, the heat of the superheater provided outside the pipe is transferred to the pipe via the heat transfer section, so that the heat of the superheater is efficiently transferred to the pipe, and the heat of the superheater efficiently heats the pipe. Steam can be superheated. In addition, by joining the evaporating part and the superheating part at the joining part, when the heat of the evaporating heater is transferred to the superheating part or when the heat of the superheating heater is transferred to the evaporating part, the substance that acts as resistance to heat transfer is eliminated. By minimizing the amount of intervening heat, quick heat transfer becomes possible.

A sixth invention is a cooker equipped with the superheated steam generator of any one of the first to fifth inventions. This enables high-performance cooking using superheated steam.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. Also, the present invention is not limited by this embodiment.

(Embodiment 1)
A configuration of a superheated steam generator and a cooker equipped with the superheated steam generator according to Embodiment 1 of the present invention will be described with reference to FIGS. 1 to 8. FIG. FIG. 1 shows a perspective view of a superheated steam generator according to Embodiment 1 of the present invention. FIG. 2 shows an exploded perspective view of the superheated steam generator according to Embodiment 1 of the present invention. FIG. 3 shows an external view of the superheated steam generator viewed from the X direction in FIG. FIG. 4 shows an external view of the superheated steam generator viewed from the Y direction in FIG. FIG. 5 shows a cross-sectional view taken along line AA in FIG. FIG. 6 shows a cross-sectional view taken along line BB in FIG. FIG. 7 shows a sectional view taken along line CC in FIG. FIG. 8 shows a schematic diagram of the configuration of an oven equipped with a superheated steam generator according to Embodiment 1 of the present invention.

As shown in FIGS. 1 to 7, the superheated steam generator 10 according to the first embodiment includes a heating container 11 having a space-like heating container interior 11A and an opening of the heating container 11. It has a heating container cover 12 and a water supply pipe 13A attached to the outer surface of the heating container cover 12 and supplying water to the inside 11A of the heating container. A water supply port 13, which is one end of the water supply pipe 13A, communicates with the inside of the heating container 11A. A plurality of fins are formed in the inside 11A of the heating container so that the flow path through which the water supplied from the water supply port 13 flows meanders.

The inside 11A of the heating container is formed in a substantially rectangular parallelepiped shape, and one short side portion is formed in a U shape. The superheated steam generator 10 further includes an evaporating heater 14 and a superheating heater 15 which are U-shaped heaters. An evaporative heater 14, a superheater 15 and a pipe 16 are embedded in the heating container 11 so that the evaporative heater 14, the superheater 15 and the pipe 16 are in close contact with each other in the heating container 11A. The evaporation heater 14 is configured to evaporate the water supplied to the heating container 11 from the water supply port 13 by heating the heating container 11 . The pipe 16 has a structure through which the vapor generated in the heating container 11A by the evaporation heater 14 passes. One end of the pipe 16 is separated from the heating container cover 12 and communicates with the inside 11A of the heating container. The superheater 15 is arranged outside the pipe 16 and heats the pipe 16 to superheat the steam passing through the pipe 16 .

As shown in FIGS. 4 and 6, water is supplied from the outside through a water supply pipe 13A into the heating vessel 11A from a water supply port 13. As shown in FIG. The water supplied from the outside is assumed to be tap water, and is usually supplied at a temperature of 0 to 30°C. The water a supplied to the inside 11A of the heating container passes through the flow path along the straight portion 14b which is the longitudinal direction of the evaporation heater 14 inside the heating container 11A. By forming the flow path along the straight portion 14b, the distance between the flow path in the heating container 11A and the evaporative heater 14 becomes short, and the heat of the evaporative heater 14 is easily transferred to the flow path. The water a supplied to the inside 11A of the heating container passes through the flow path of the inside 11A of the heating container, and the water a receives heat from the heating container 11 heated by the evaporation heater 14 and is heated. By configuring the flow path of the heating container 11 so that the water a meanders, the contact area between the heating container 11 and the water a can be increased, and the heat exchange efficiency can be improved. The water a heated in the heating container 11A starts to evaporate when the pressure in the heating container 11A reaches around 100° C. when the pressure in the heating container 11A is atmospheric pressure. The evaporated water a moves inside the heating container 11A as steam b indicated by a dotted line in FIG. When the vapor b evaporates in the flow path of the heating container 11A, it can be superheated to 100.degree.

The vapor b in the heating vessel 11A evaporated by the evaporation heater 14 moves to the pipe 16 as shown in FIGS. As shown in FIGS. 7 to 9, a superheater 15 is provided outside the pipe 16, and the heat of the superheater 15 is transferred to the pipe 16 via the heating container 11. As shown in FIG. The steam b passing through the pipe 16 and having a temperature of 100° C. or more contacts the inner surface of the pipe 16 heated by the superheater 15 , is further heated, and is discharged from the other end of the pipe 16 to the outside.

Further, as shown in FIGS. 5 and 7, a heat exchange promoting portion 17 is provided in the pipe 16, and the heat exchange promoting portion 17 is formed between a core rod 17a arranged in the center of the pipe 16 and an outer periphery of the core rod 17a. It is composed of a spiral body 17b wound around. The core rod 17a and the spiral body 17b are welded and fixed at the joint 17c of the spiral body 17b and the core rod 17a. The spiral body 17b and the pipe 16 are welded and fixed at the joint 17d of the spiral body 17b and the pipe 16. As shown in FIG. The steam b in the heating container 11A evaporated by the evaporation heater 14 flows outside the core rod 17a at the center of the pipe 16 and along the spiral body 17b. Go straight through the gaps between the pipes 16 . The steam moving along the spiral body 17b has a larger contact area with the inner surface of the pipe 16, and can improve the heat exchange efficiency. The steam that does not follow the spiral body 17b is also separated from the inner surface of the pipe 16 by the core rod 17a, so that the steam does not pass through the central part of the pipe 16 where heat is difficult to transfer, so that the steam passes near the inner surface of the pipe 16. This also has the effect of improving the heat exchange efficiency. Further, by providing the heat exchange promoting portion 17, the flow passage area in the pipe 16 is reduced, and the flow velocity of the steam b is increased, so that the convective heat flux between the inner surface of the pipe 16 and the steam b can be increased. By providing the heat exchange promoting section 17, even if the superheater 15 is controlled at a temperature not exceeding 300°C, the temperature of the superheated steam can be increased to 250°C or higher.

The positional relationship between the evaporation heater 14 and the superheater 15 will be described with reference to FIGS. 3, 4 and 7. FIG. The evaporating heater 14 and the superheating heater 15 have a circular cross-section.

When each heater of the evaporative heater 14 and the superheat heater 15 is U-shaped, the same heater has two straight portions like the straight portion 14b of the evaporative heater 14 in FIG. When the straight portions of the evaporative heater 14 and the superheater 15 are arranged in parallel, the distance d between the evaporative heater axes and the distance e between the superheater heater axes in FIG. and the maximum inter-axis distance of the linear portion of the overheating heater 15 .

In the superheated steam generator 10 of the present embodiment, the distance between the evaporative heater 14 and the superheater 15 is greater than the maximum distance d between the axes of the linear portion 14 b of the evaporative heater 14 and the maximum distance e between the axes of the linear portion 15 of the superheater 15 . is configured so that the minimum value of the inter-axis distance c of is small. With such a configuration, the heat of the evaporative heater 14 can be easily transmitted to the vicinity of the superheater 15 , and the heat of the evaporative heater 14 can also be used to superheat the steam passing through the pipe 16 . On the contrary, the heat of the superheater 15 can be easily transferred to the vicinity of the evaporation heater 14, so that the heat of the superheater 15 can be used for evaporating water.

Evaporation heaters and overheating heaters are not limited to one U-shaped heater, but may be composed of two or more linear heaters, or may be composed of two or more curved heaters. Also, the minimum value of the distance between the axes of the evaporative heater and the superheater shall be smaller than the maximum distance between the axes of the straight parts of the evaporative heater and the maximum distance between the axes of the straight parts of the superheater. to get the same effect.

As an assumed usage method of the superheated steam generator 10 of the present embodiment, first, the superheater 15 is preheated to a predetermined temperature of 100° C. or higher, and then water is supplied from the water supply port 13 to the heating container 11A. , water is evaporated by the evaporation heater 14, the evaporated steam is superheated by passing it through the pipe 16 heated by the superheater 15, and the superheated steam at a predetermined temperature of 100° C. or higher is discharged to the outside.

For example, under the condition that water at 10°C is supplied at 0.3g/s, when the specific heat of water is 4.2J/(g°C) and the latent heat of vaporization is 2250J/g, it takes 1 second to evaporate water. requires a minimum power of about 790 W. Under the condition that steam of 100°C passes through the pipe 16 at 0.3 g/s, when the temperature is raised to 250°C by the superheater 15, the specific heat of the steam is 2.1 J/(g·°C). The lowest power required is approximately 100 W, which is less power consumption than the evaporation heater 14 .

However, in order to superheat the steam, it is necessary to raise the temperature of the superheater 15, the pipe 16, and the heating container 11 around the pipe 16 to a predetermined temperature in the preheating stage. At 100 W, there is a possibility that the temperature cannot be raised to the predetermined temperature within the specified preheating time.

Conversely, if the power consumption of the superheater 15 is designed to be 100 W or more in order to raise the temperature to a predetermined temperature within the specified preheating time, the power consumption becomes excessive after preheating is completed, and the superheater 15 is kept at a predetermined temperature. However, if the power consumption that can be used by the entire superheated steam generator is limited, the power cannot be used as heat when the superheater 15 is off, and is wasted. Become.

For example, under the condition that the power consumption of the entire superheated steam device is 1300 W or less, if 600 W is required to raise the temperature of the superheater 15, the pipe 16, and the heating container 11 around the pipe 16 to a predetermined temperature within the preheating time, The power consumption that can be used by the evaporation heater 14 is 700 W or less. If it is desired to evaporate water at 0.3 g/s, the power consumption of the evaporation heater 14 is insufficient.

In addition, since 100 W is sufficient for the superheating heater 15 once preheating is completed to superheat the steam, 500 W becomes redundant in the superheating heater 15 even though the power consumption of the evaporating heater 14 is insufficient. Become.

At this time, as in the present embodiment, the distance c between the axes of the evaporative heater 14 and the overheating heater 15 is reduced so that the heat of the overheating heater 15 can be easily transmitted to the vicinity of the evaporating heater 14. By transferring the surplus electric power of the heater 15 as heat to the vicinity of the evaporation heater 14 and using it to raise the temperature and evaporate the water, it is possible to make up for the shortage of the power consumption of the evaporation heater 14 . On the contrary, in the preheating stage, the heat of the evaporation heater 14 is not used for evaporating water. can be used to raise the temperature of the heating container 11 to a predetermined temperature.

The superheated steam generator 10 of the present embodiment can be mounted on a cooking device that uses superheated steam for cooking, such as a heating oven as shown in FIG. In FIG. 8 , the water stored in the water storage tank 4 is supplied into the superheated steam generator 10 by the pump 5 . The water supplied into the superheated steam generator 10 is turned into a predetermined superheated steam of 100° C. or higher by the superheated steam generator 10 and introduced into the heating chamber 2 in the heating oven main body 1, thereby cooking using superheated steam. becomes possible. Moreover, the cooker is not limited to a heating oven, and can be used as a cooker such as a rice cooker or a microwave oven.

(Embodiment 2)
The configuration of the superheated steam generator according to Embodiment 2 of the present invention will be described with reference to FIGS. 9 and 10. FIG. FIG. 9 shows a perspective view showing a state where the superheated steam generator according to Embodiment 2 of the present invention is joined at the joining portion. FIG. 8 shows an exploded perspective view of a superheated steam generator according to Embodiment 2 of the present invention.

In the embodiment of the present invention, matters different from those of Embodiment 1 will be explained, and explanations of those having the same configuration, effect, etc. as those of Embodiment 1 will be omitted.

As shown in FIGS. 9 and 10, the superheated steam generator 10 according to the second embodiment includes a heating vessel 11, a water supply pipe 13A for supplying water into the heating vessel 11, an evaporating section 20 composed of an evaporating heater 14, A superheating section 21 composed of the superheating heater 15, the pipe 16, and the heat transfer section 18 provided between the superheating heater 15 and the pipe 16 is joined at the evaporating section joining section 19a and the superheating section joining section 19b. ing.

The superheated steam generator 10 in Embodiment 2 has a configuration that can be separated into an evaporating section 20 and a superheating section 21 .

In the overheating unit 21, the heat transfer unit 18 is arranged so as to cover the gap and the surroundings of the overheating heater 15 and the pipe 16 so as to be in close contact with each other, so that the heat from the surface of the overheating heater 15 is It can be transmitted to the pipe 16 quickly.

By configuring the superheated steam generator 10 to be separated into the evaporating section 20 and the superheating section 21 as in the second embodiment, when the evaporating section 20 and the superheating section 21 are joined together, the evaporating section 20 and the superheating section 21 By providing a heat insulating material or an air layer on the contact surface, it is possible to partially suppress the amount of heat transmitted from the evaporative heater 14 or the superheater 15 to the vicinity of the superheater 15 or the vicinity of the evaporative heater 14 . For example, the heat in the vicinity of the pipe 16 in the superheating unit 21 is important for superheating the steam, so if water comes into contact with the vicinity of the pipe 16 and excessive heat is taken away by the water, the amount of heat in the vicinity of the pipe 16 becomes insufficient. However, the steam passing through pipe 16 may not be sufficiently superheated. Therefore, by providing a heat insulating material in a part of the contact portion between the pipe 16 of the superheating part 21 and the evaporating part 20, heat transfer from the pipe 16 of the superheating part 21 near the evaporating part 20 is suppressed, and the inside of the pipe 16 is suppressed. The amount of heat can be retained to superheat the passing steam.

INDUSTRIAL APPLICABILITY The present invention realizes an improvement in the heat exchange efficiency of a superheated steam generator, and can be used in other fields such as drying equipment and sterilizing equipment that use superheated steam in addition to cooking machines.

a water b steam c distance between axes d distance between axes e distance between axes 1 heating oven main body 2 heating chamber 4 water storage tank 5 pump 10 superheated steam generator 11 heating vessel 11A heating vessel interior 12 heating vessel cover 13 water inlet 13A water supply pipe 14 Evaporation heater 14a Evaporation heater shaft 14b Straight part 15 Overheating heater 15a Overheating heater shaft 16 Pipe 17 Heat exchange promoting part 17a Core rod 17b Spiral body 17c Joint part 17d Joint part 18 Heat transfer part 19a Evaporation part joint part 19b Superheating part joint part 20 Evaporator 21 Superheater

Claims (6)

a heating vessel;
a water supply port for supplying water to the heating container;
an evaporation heater that heats the heating container to evaporate the water supplied to the heating container from the water supply port;
a pipe through which the vapor generated by the evaporative heater passes;
a superheater disposed outside the pipe and heating the pipe to superheat steam passing through the pipe;
the evaporating heater and the superheating heater have two or more linear portions ,
The linear portion of the evaporative heater and the linear portion of the overheating heater facing each other are configured to be parallel and parallel,
The minimum distance between the axes of the cross-sectional centers of the evaporative heater and the superheater is
A superheated steam generator configured to be shorter than the maximum distance between the axes of the cross-sectional centers of the straight portions of the evaporative heater and the maximum distance between the axes of the cross-sectional centers of the straight portions of the overheating heater. The water supplied from the water inlet moves along the longitudinal direction of the evaporative heater, and the steam generated by the evaporative heater moves along the longitudinal direction of the evaporative heater or the superheater. The superheated steam generator according to claim 1. A heat exchange promoting part is provided in the pipe,
2. The superheated steam generator according to claim 1, wherein the heat exchange promoting part comprises a core rod and a spiral body wound around the outer periphery of the core rod. a heating vessel;
a water supply port for supplying water to the heating container;
an evaporation heater that heats the heating container to evaporate the water supplied to the heating container from the water supply port;
a pipe through which the vapor generated by the evaporative heater passes;
a superheater disposed outside the pipe and heating the pipe to superheat steam passing through the pipe;
the evaporating heater and the superheating heater have two or more linear portions,
The minimum distance between the axes of the evaporative heater and the superheater is
configured to be shorter than the maximum distance between the axes of the straight portions of the evaporative heater and the maximum distance between the axes of the straight portions of the overheating heater,
A superheated steam generator, wherein the evaporating heater, the pipe, and the superheating heater are in close contact with the heating vessel. A heat transfer section is provided between the pipe and the superheater,
2. The apparatus according to claim 1, further comprising a joining portion for joining an evaporating portion including the heating container, the water inlet, and the evaporating heater, and a superheating portion including the pipe, the superheater, and the heat transfer portion. Superheated steam generator. A cooker comprising the superheated steam generator according to any one of claims 1 to 5.

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