JP5860340B2 - Liquid heater - Google Patents

Description

  The present invention relates to a liquid heater including a storage unit that stores a liquid to be heated, a heating unit that heats the liquid in the storage unit, and a control unit that adjusts the heating amount of the heating unit.

  Such a liquid heater heats the liquid (for example, water) in a storage part by a heating means and causes saturation boiling. Specific examples include a humidifier, an electric kettle, and an electric pot. By the way, “saturation boiling” is a state in which almost the entire liquid in the storage part reaches a substantially saturated temperature, and when the liquid in the storage part reaches a saturated boiling state, the liquid evaporates in the liquid in the storage part. Most of the generated vapor bubbles rise to the liquid level in the reservoir without bursting in the liquid in the reservoir and rupture at the liquid level.

  In such a liquid heater, conventionally, temperature detection means for detecting the temperature of the liquid in the storage section is provided, and based on the detection information of the temperature detection means, the control means immediately before the liquid in the storage section saturates and boils. The heating amount of the heating unit is adjusted so that the heating unit is heated with high energy until the set temperature (for example, 98 ° C.) is reached, and the heating unit is heated with low energy after reaching the set temperature. There was a thing (for example, refer to patent documents 1). As a result, after starting the heating operation of the heating means, that is, after starting the heating of the liquid in the storage unit, it is possible to save energy while shortening the rise time until the liquid in the storage unit is saturated and boiled. ing.

JP-A-9-96427

  By the way, in such a liquid heater, after heating the heating means to start heating the liquid in the storage part, in the temperature rising process until the liquid in the storage part is saturated and boiled, noise that is annoying to the user ( When the noise “shear” is generated and reaches a saturated boiling state, the noise is reduced. Such noise is not only harshing for the user, but also causes inconveniences such as difficulty in listening to the conversation, and improvement has been desired.

  The present invention has been made in view of such circumstances, and its purpose is to generate a temperature rise process until saturation boiling while preventing a rise time until the liquid in the reservoir is saturated and boiled. An object of the present invention is to provide a liquid heater that can reduce noise.

In order to achieve the above object, a liquid heater according to the present invention includes a storage unit that stores a liquid to be heated, a heating unit that heats the liquid in the storage unit, and a control unit that adjusts the heating amount of the heating unit. A liquid heater comprising:
In the temperature rising process until the liquid in the storage unit is heated to saturation boiling by the heating unit, the vapor bubbles generated in the heat transfer unit that transfers the heat from the heating unit to the liquid in the storage unit are A plosive generation suppression period is set to suppress a plosive generated by bursting in the liquid in the reservoir,
The control means makes the average value of the heating amount of the heating means in the burst sound generation suppression period smaller than the average value of the heating amount of the heating means in the initial heating period until the burst sound generation suppression period. In the point.

  In such a liquid heater, the temperature of the liquid in the entire storage unit does not reach the saturation temperature in the temperature rising process from the start of heating of the liquid in the storage unit to saturation boiling, and in the vicinity of the heat transfer unit. When the temperature of the liquid reaches the saturation temperature, a so-called subcooled boiling state occurs in which the liquid locally evaporates and vapor bubbles are generated in the heat transfer section (including the vicinity of the heat transfer section). When the vapor bubbles generated in the subcooled boiling state move away from the heat transfer section (including the vicinity of the heat transfer section) to a region where a liquid having a temperature lower than the saturation temperature exists, the vapor bubbles condense and collapse in the region. Bursts in the liquid in the reservoir and generates a popping sound. As described above, this plosive sound becomes annoying noise for the user. In addition, after the subcooled boiling state, that is, in a state where the temperature of the liquid in the entire storage unit reaches a substantially saturated temperature (saturated boiling state), not only the heat transfer unit (including the vicinity of the heat transfer unit) but also the storage unit The liquid evaporates as a whole, and vapor bubbles are generated. Most of these vapor bubbles reach the surface of the liquid without condensing and collapsing (breaking) in the liquid in the reservoir, and the above-mentioned burst sound ( Noise) is reduced.

Therefore, according to the above characteristic configuration, in the temperature rising process, the vapor bubble separated from the heat transfer part (including the vicinity of the heat transfer part) is condensed and collapsed during the period in which the liquid in the storage part is in a subcooled boiling state. The burst generation suppression period is set in the period for suppressing the generated plosive sound, and the control means reaches the average value of the heating amount of the heating means in the plosive generation suppression period to the burst generation suppression period. The heating amount of the heating unit is adjusted so as to be smaller than the average value of the heating amount of the heating unit in the initial heating period until.
That is, in a state where the temperature of the liquid in the entire reservoir in the temperature rising process has not reached the saturation temperature, the liquid in the vicinity of the heat transfer portion among the liquid in the reservoir during the initial heating period until the plosive generation suppression period is reached. The temperature of the water still has not reached the saturation temperature (not in a subcooled boiling state), and almost no vapor bubbles are generated in the heat transfer section (including the vicinity of the heat transfer section). Therefore, the control means can heat the heating means in a relatively high energy state to raise the temperature of the liquid in the reservoir as fast as possible.
On the other hand, in the state where the temperature of the liquid in the entire storage portion in the temperature rising process has not reached the saturation temperature, the temperature in the vicinity of the heat transfer portion of the liquid in the storage portion is reduced during the plosive generation suppression period after the initial heating period. When the temperature reaches the saturation temperature (becomes a subcooled boiling state), many steam bubbles are generated in the heat transfer section (including the vicinity of the heat transfer section). For this reason, the control unit performs the heating operation in the low energy state lower than the high energy state in the initial heating period in the burst sound generation suppression period, and the unit time is longer than that in the case where the heating unit is heated in the high energy state. The number of vapor bubbles generated per unit time can be reduced, and the number of vapor bubbles condensed and broken down in the liquid per unit time can be reduced. Can be reduced.
Therefore, it is possible to provide a liquid heater that can reduce the noise generated in the temperature raising process until saturation boiling until the rise time until the liquid in the reservoir is saturated and boiled is lengthened.

According to a further characteristic configuration of the liquid heater according to the present invention, the plosive generation suppression period is divided into a plurality of periods,
The control means is such that the average value of the heating amount of the heating means in each of the plurality of periods is made smaller as the time elapses from the start of the plosive generation suppression period.

As the time from the start of the plosive sound generation suppression period elapses, the temperature of the liquid in the vicinity of the heat transfer section increases, so that steam bubbles are likely to be generated.
So, according to the said characteristic structure, the average value of the heating amount of the heating means in each of several periods of a plosive generation | occurrence | production suppression period is made small as the period by which the time from the start of a plosive generation suppression period passes. As a result, not much time has elapsed since the start of the plosive generation suppression period, and the average value of the heating amount of the heating means is relatively increased and the noise is increased in a period in which the generation of steam bubbles is relatively small. In a period in which the temperature of the liquid in the reservoir is increased while the amount of steam bubble generation is relatively low and the generation of vapor bubbles is relatively large over time, the average value of the heating amount of the heating means is relatively small, Noise can be reduced by reducing the number of steam bubbles generated per hour.
Therefore, the noise generated from the liquid heater can be surely reduced while further preventing the rise time from becoming longer.

According to a further feature of the liquid heater according to the present invention, the heating means is constituted by an electric heating means for heating the liquid by converting electric power into heat energy,
In order to make the average value of the electric power supplied to the electric heating unit in the burst sound generation suppression period smaller than the average value of the electric power supplied to the electric heating unit in the initial heating period, the control unit The point is to control the operation of the electric heating means.

According to the above characteristic configuration, by configuring the heating means with the electric heating means, the power supplied to the electric heating means can be adjusted with high accuracy, and the average value of the heating amount can be adjusted with high accuracy. Since this can be done, the number of vapor bubbles generated per unit time can be accurately reduced during the plosive generation suppression period.
Therefore, noise generated from the liquid heater can be accurately reduced.

  In a further characteristic configuration of the liquid heater according to the present invention, the control means has the same electric power of the electric heating means as the electric power of the electric heating means in the initial heating period in the burst sound generation suppression period. Or a high power period for adjusting to a high set power set to a power lower than that power, and a low power period for adjusting the power of the electric heating means to a low set power lower than the high set power or zero. In the form of repeating the cycle consisting of: at least one of the duty ratio of the high power period, the high set power, and the low set power is configured to adjust the power supplied to the electric heating means By adjusting the average value of the electric power supplied to the electric heating means to adjust the average value of the heating amount of the heating means.

According to the above characteristic configuration, in the pop sound generation suppression period, by adjusting the power supplied to the electric heating means in a form in which a cycle consisting of a high power period and a low power period is repeated, the rise of the liquid in the reservoir is increased. While ensuring the desired speed, the amount of steam bubbles generated per unit time throughout the burst sound generation suppression period can be reduced by setting the heating amount to a minimum or zero during the low power period of each cycle. It can be reduced more reliably.
Therefore, noise generated from the liquid heater can be reduced more reliably.

A further characteristic configuration of the liquid heater according to the present invention is provided with a temperature detection means for detecting the temperature of the liquid in the reservoir,
The plosive generation suppression period is set based on detection information of the temperature detection means.

The ease of generation of vapor bubbles in the vicinity of the heat transfer section during the plosive generation suppression period depends on the temperature of the liquid in the vicinity of the heat transfer section in the storage section.
Therefore, according to the above characteristic configuration, since the plosive generation suppression period can be accurately set based on the detection information of the temperature detection means for detecting the temperature of the liquid in the reservoir, in the plosive generation suppression period, By heating the heating means with low energy, the number of vapor bubbles generated per unit time can be reduced, and the noise generated from the liquid heater can be reduced appropriately.

  A further characteristic configuration of the liquid heater according to the present invention is that the whole or a part of the period from when the temperature detected by the temperature detecting means reaches 50 ° C. until it reaches 90 ° C. is the suppression of the generation of the plosive sound. The point is that the period is set.

The inventors of the present invention conduct experiments to examine the correlation between the temperature of the liquid in the reservoir and the state of generation of vapor bubbles, and the detected temperature of the temperature detecting means reaches 90 ° C. after reaching 50 ° C. It was confirmed that it became a subcooled boiling state in the period up to.
According to the above characteristic configuration, the period from when the temperature detected by the temperature detecting means reaches 50 ° C. until it reaches 90 ° C., that is, the period during which a relatively large amount of vapor bubbles are generated due to the subcooled boiling state and burst in the liquid. Therefore, the plosive generation suppression period is accurately set to a period during which noise should be reduced.
Therefore, the burst generation suppression period is accurately set to a period during which noise should be reduced, and in the burst generation suppression period, the heating means is operated with low energy to reduce the number of steam bubbles generated per unit time. Since it reduces, the noise generated from a liquid heater can be reduced appropriately.

  The liquid heater according to the present invention is further characterized in that the control means controls the heating amount of the heating means during a period during which the detected temperature of the temperature detection means is higher than a predetermined set temperature in the burst sound generation suppression period. Is that the temperature detected by the temperature detecting means is smaller than the average value of the heating amount of the heating means during a period in which the temperature is not more than the set temperature.

In the plosive generation suppression period, since the temperature of the liquid in the vicinity of the heat transfer section is higher in the end side period than in the start side period with a predetermined set temperature as a boundary, steam bubbles are likely to be generated. .
According to the above characteristic configuration, in the period on the start side of the plosive generation suppression period in which vapor bubbles are not yet easily generated, noise is increased by relatively increasing the average value of the heating amount of the heating means. In the period on the end side of the plosive generation suppression period in which the temperature rise of the liquid in the storage portion is accelerated while suppressing vaporization and vapor bubbles are likely to be generated, the average value of the heating amount of the heating means is relatively small, and unit time Noise is reduced by reducing the number of steam bubbles generated per hit.
Therefore, the noise generated from the liquid heater can be reduced while further preventing the rise time from becoming longer.

Perspective view showing the appearance of the humidifier Perspective view of humidifier with part of lid cut out Humidifier longitudinal section Vertical section of electric heater unit Block diagram showing the control configuration of the humidifier The figure which shows the time chart of the temperature of the water in an inner container, and the time chart of control action The figure which shows the time chart of the temperature of the water in an inner container, and the time chart of control action The figure which shows the relationship between the temperature of the water in the inner container and the magnitude of the noise generated from the humidifier The figure which shows the time chart of the control action which concerns on another embodiment The figure which shows the time chart of the control action which concerns on another embodiment The figure which shows the time chart of the control action which concerns on another embodiment The figure which shows the time chart of the control action which concerns on another embodiment The figure which shows the time chart of the control action which concerns on another embodiment The figure which shows the time chart of the control action which concerns on another embodiment

Hereinafter, based on the drawings, an embodiment when the present invention is applied to a humidifier as an example of a liquid heater will be described.
As shown in FIGS. 1 to 3, this humidifier has a generally bottomed cylindrical container body 100 having an inner container 1 (an example of a storage part) that stores water W (an example of a liquid) to be heated. And a generally disc-shaped lid 200 that can open and close the opening 2 at the top of the container main body 100. The lid body 200 is supported by the hinge portion 3 provided at the opening edge of the container body 100 so as to be swingable around a horizontal axis, and by a swing operation using the hinge portion 3 as a swing axis, The opening 2 of the container body 100 can be freely opened and closed.

As shown in FIG. 3, the container body 100 is configured such that an annular rim member 5 is fitted into a lip portion of a bottomed cylindrical outer shell member 4, and the bottomed cylindrical inner container 1 is fitted to the lip member 5. The lid 200 is configured to freely open and close the opening 2 of the rim member 5 (that is, the container main body 100).
As shown in FIGS. 1 and 3, the container body 100 heats the water W stored in the inner container 1 and can adjust the heating amount thereof, and the heating amount of the heating unit H. The controller 7 (an example of the control means) that controls the operation of the humidifier, such as adjustment of the temperature, a temperature sensor 8 (an example of the temperature detection means) that detects the temperature of the water W in the inner container 1, and the controller 7 are operated. An operation unit 9 for transmitting control information, a handle 6 and the like are provided.

Next, each part of the container body 100 will be described.
As shown in FIGS. 3 and 4, the bottom of the inner container 1 is provided with a heater mounting recess 1a that is recessed upward, and the sensor mounting recess that is further recessed upward in the center of the heater mounting recess 1a. A recess 1b is provided.
The heating means H is constituted by an electric heater unit 10 (an example of an electric heating means) that converts water into heat energy and heats the water W. The electric heater unit 10 has a sensor arrangement hole 10h in the center. It is comprised in the board shape provided with. The electric heater unit 10 is fitted in the heater mounting recess 1 a and is supported by the heater receiving member 30 below the bottom portion of the inner container 1. Further, the temperature sensor 8 is connected to the electric heater unit 10. A sensor receiving member 31 connected to the heater receiving member 30 below the bottom of the inner container 1 in a state of being accommodated in the sensor mounting recess 1b through the sensor mounting hole 10h and in contact with the bottom of the inner container 1. Supported by That is, the temperature sensor 8 is configured to detect the temperature of the portion facing the sensor mounting hole 10 h of the electric heater unit 10 at the bottom of the inner container 1 as the temperature of the water W in the inner container 1.

  As shown in FIG. 4, the electric heater unit 10 includes a plate-like main heater 11 and a humidifying heater 12. Specifically, the electric heater unit 10 includes a main heater 11, a humidifying heater 12, and three insulating plates 13 stacked in this order: an insulating plate 13, a humidifying heater 12, an insulating plate 13, a main heater 11, and an insulating plate 13. In the state, it is housed in a flat box-like heater case 14 and configured in a disk shape.

The heater case 14 is made of a metal having excellent heat conductivity, such as aluminum, and includes a cylindrical inner wall portion 14h for forming the sensor arrangement hole 10h in the center portion.
The main heater 11 and the humidifying heater 12 are so-called mica heaters. The mica heater is configured by winding a heating wire 16 (for example, nichrome wire) around a mica (mica) heat dissipation plate 15, and an inner wall portion 14 h of the heater case 14 is inserted through a substantially central portion of the heat dissipation plate 15. Holes are provided.
The insulating plate 13 is made of a plate-shaped material made of mica, and is provided with a hole through which the inner wall portion 14h of the heater case 14 is inserted at a substantially central portion.
The main heater 11 has a higher output than the humidifying heater 12, and the main heater 11 is supplied with, for example, a rated power of 575 W, and the humidifying heater 12 is supplied with a rated power of 410 W, for example.

When the electric heater unit 10 is energized and heated, the heat generated from the electric heater unit 10 is transferred to the water W in the inner container 1 through the bottom of the inner container 1, Water W is heated and boiled, and steam S is generated.
That is, as shown in FIG. 3 and FIG. 4, the portion of the bottom surface of the inner container 1 facing the inside of the inner container 1 in the heater mounting recess 1 a faces the sensor arrangement hole 10 h of the electric heater unit 10. The portion excluding the portion functions as the heat transfer section 17 that transfers the heat generated from the electric heater unit 10 to the water W in the inner container 1.
Incidentally, in this embodiment, the area of the heat transfer section 17 is set to 133 cm ^2, and the ratio of the area of the heat transfer section 17 to the area of the entire bottom surface of the inner container 1 is set to about 66%.

  As shown in FIG. 1, the operation unit 9 is configured as a panel type including a plurality of sheet-like switches, and is provided on the side peripheral surface of the outer member 4. The plurality of switches provided in the operation unit 9 include an operation switch 9a for instructing operation and stop of the humidifier, a normal mode switch 9b for instructing a normal operation mode, a silent mode switch 9c for instructing a silent operation mode, and the like. It is.

As shown in FIG. 1, in the space between the outer member 4 and the inner container 1, a heater drive that controls the operation of the control unit 7 and the electric heater unit 10 is provided at a position corresponding to the back surface of the operation unit 9. An electrical component case 19 that houses electrical components such as the portion 18 is provided.
As shown in FIG. 5, the control unit 7 includes a microcomputer, and receives control information from the operation unit 9 and detection information from the temperature sensor 8. Based on the input information, the control unit 7 includes the control unit 7. In order to control the heating operation, the operation of the heater driving unit 18 is controlled.

The heater driving unit 18 supplies the rated electric power Ph (985 W in this embodiment) to the electric heater unit 10 by supplying respective rated power to the main heater 11 and the humidifying heater 12 in the heating operation state of the electric heater unit 10. Steam for supplying steam bubble suppression power Pm (in this embodiment, 575 W) lower than the temperature-raising power Ph to the electric heater unit 10 by supplying rated power to the main heater 11. In the power supply state for foam suppression, the rated power is supplied to the humidifying heater 12 and the power supply for heat retention Pk (410 W in this embodiment) lower than the steam bubble suppression power Pm is supplied to the electric heater unit 10. It can be switched to 3 types.
And the control part 7 is comprised so that the heating amount of the electric heater unit 10 may be adjusted by controlling the action | operation of the heater drive part 18 and adjusting the electric power supplied to the electric heater unit 10. FIG.

Next, the lid 200 will be described.
As shown in FIGS. 2 and 3, the lid body 200 is provided with a steam channel 21 in a recessed shape, and a steam port mounted in a state of covering the upper opening of the steam channel 21. A cover 22 is detachably provided, and a suction port 23 that opens to the outside is provided in a side wall portion that forms the vapor flow path 21 in the lid 200. The steam port cover 22 is configured in a lattice shape having ribs in a grid pattern so as to be ventilated.
The lid body 200 is provided with a lid opening / closing lever 24 for opening and closing the lid body 200 and a lock knob 25 for holding the lid body 200 in a closed state while being operable from above. Yes.

As shown in FIGS. 2 and 3, the lid 200 is further provided with a steam ejection nozzle 26 and a reflux unit 27.
The vapor ejection nozzle 26 is composed of a flexible tube, and with one end opening communicating with the inner container 1 and the other end opening with the lid 200 attached to the container body 100 in a closed state. Is provided so as to face the steam flow path 21. Although not shown in the drawings, the reflux unit 27 has a reflux hole that allows the inside of the inner container 1 and the steam channel 21 to communicate with each other in a state in which the lid 200 is attached to the container body 100 in a closed state. And a reflux valve that opens and closes the hole.

A space having a predetermined volume is formed between the water surface Ws of the water W stored in the inner container 1 and the lower surface of the lid body 200 in a state where the lid body 200 is attached to the container body 100 in a closed state. The maximum storage capacity of the water W in the inner container 1 is set. Incidentally, in this embodiment, the maximum storage capacity is set to 3.0 liters, for example.
Then, as shown in FIG. 3, when water W is stored in the inner container 1 with a capacity equal to or less than the maximum storage capacity, and the lid 200 is attached to the container main body 100 in a closed state, the water W in the inner container 1 is above the water surface Ws. A vapor-filled space 28 that is closed by the lid 200 is formed. The recirculation valve constituting the recirculation part 27 has a recirculation hole as the water W in the inner container 1 boils and steam S is generated by heating by the electric heater unit 10, and the internal pressure of the steam-filled space 28 increases. On the other hand, the energization of the electric heater unit 10 is stopped, the generation of the steam S in the inner container 1 is stopped, and the internal pressure of the steam-filled space 28 is reduced, so that the reflux hole is caused by its own weight. Is configured to open.

  Therefore, when the water W stored in the inner container 1 is boiled and the steam S is generated, the steam S fills the steam filling space 28 and is ejected into the steam channel 21 through the steam ejection nozzle 26. Then, it passes through the plurality of holes of the steam port cover 22 and is discharged to the humidification target space (outside).

Next, the control operation of the control unit 7 will be described.
When the start of the humidification operation is commanded by the operation switch 9a of the operation unit 9, the control unit 7 starts the humidification operation for heating the electric heater unit 10 and when the operation switch 9a is commanded to stop the humidification operation. Then, the heating operation of the electric heater unit 10 is stopped and the humidifying operation is stopped.
Further, during the humidification operation, the control unit 7 is configured to execute the humidification operation in the normal operation mode when the normal mode switch 9b is pressed, and to execute the humidification operation in the silent operation mode when the silent mode switch 9c is pressed. Thus, it is possible to switch between the humidifying operation in the normal operation mode and the humidifying operation in the silent operation mode.

In the present invention, in the humidifying operation in the silent operation mode, the heating means H (in this embodiment, the electric heater unit 10) heats the water W in the inner container 1 and heats it up until saturation boiling. Burst generated by vapor bubbles B generated in the heat transfer section 17 for transferring heat from the means H (electric heater unit 10) to the water W in the inner container 1 in the water W in the inner container 1 A plosive generation suppression period for suppressing sound is set.
In the humidifying operation in the silent operation mode, the control unit 7 sets the average value of the heating amount of the heating unit H during the plosive generation suppression period to the heating amount of the heating unit H during the initial heating period until the plosive generation suppression period. Smaller than the average value of. Here, the average value of the heating amount of the heating means H in the initial heating period and the plosive generation suppression period is a value obtained by dividing the integrated value of the heating amount of the heating means H during the corresponding period by the time of the corresponding period. is there.
That is, in this embodiment, since the heating means H is configured by the electric heater unit 10, the control unit 7 determines the average value of the power supplied to the electric heater unit 10 during the plosive generation suppression period as the initial heating period. , The operation of the electric heater unit 10 (specifically, the operation of the heater driving unit 18) is controlled so as to be smaller than the average value of the electric power supplied to the electric heater unit 10. Here, the average value of the electric power supplied to the electric heater unit 10 in the initial heating period and the plosive generation suppression period is the time of the corresponding period of the integrated value of the electric power supplied to the electric heater unit 10 during the corresponding period. It is the value divided.

  In FIG. 3, a vapor bubble is indicated by a symbol “B”. In FIG. 3, the generation state of the vapor bubble B is schematically illustrated, and the shape of the vapor bubble B in the drawing, the generation density of the vapor bubble B, The relative relationship between the size of the vapor bubble B and each member of the humidifier such as the inner container 1 is not actual.

In this embodiment, the plosive generation suppression period is set based on the detection information of the temperature sensor 8.
Specifically, the entire period from when the detected temperature of the temperature sensor 8 reaches 50 ° C. until it reaches 90 ° C., that is, the entire period when the detected temperature of the temperature sensor 8 is 50 ° C. or more and 90 ° C. or less. In addition, a predetermined set temperature for lowering the heating amount, which will be described later, is set to 70 ° C., which is a temperature between 50 ° C. and 90 ° C.
Further, when the temperature detected by the temperature sensor 8 reaches 94 ° C., it is assumed that the water W in the inner container 1 is in a saturated boiling state, power supply to the electric heater unit 10 is started, and heating operation of the electric heater unit 10 is started. (Hereinafter, may be described as “after heating start”), a period in which the temperature detected by the temperature sensor 8 is 94 ° C. or lower is set as a temperature rising process, and the temperature detected by the temperature sensor 8 exceeds 94 ° C. After that, it is set to the heat retention process.

In the storage unit 7m (see FIG. 5) of the control unit 7, after the start of heating, a period in which the temperature detected by the temperature sensor 8 is 94 ° C. or less is stored as a temperature rising process. The period after the temperature exceeds 94 ° C. is stored as the heat retention process.
The storage unit 7m of the control unit 7 stores a period in which the temperature detected by the temperature sensor 8 is less than 50 ° C. as the initial heating period after the start of heating in the silent operation mode, and the temperature detected by the temperature sensor 8 is 50 ° C. The period of 90 ° C. or lower is stored as the plosive generation suppression period. Further, the storage unit 7m of the control unit 7 stores a period in which the temperature detected by the temperature sensor 8 is 50 ° C. or more and the heating temperature lowering set temperature is 70 ° C. or less as the first period of the plosive generation suppression period. A period in which the temperature detected by the temperature sensor 8 exceeds the set temperature for lowering the heating amount 70 ° C. and is 90 ° C. or less is stored as the second period of the plosive generation suppression period.

Next, the control operation of the control unit 7 will be further described based on the time charts shown in FIGS.
When the operation switch 9a and the normal mode switch 9b of the operation unit 9 are pressed, the control unit 7 performs a humidifying operation in the normal operation mode. In the normal operation mode, as shown in FIG. In the temperature raising process in which the temperature sensor 8 detects a temperature of 94 ° C. or lower, the heater driving unit 18 is set in a temperature raising power supply state to supply the temperature raising power Ph to the electric heater unit 10. When the temperature exceeds 94 ° C., the heater drive unit 18 is put into a heat supply state for keeping warm in order to supply the electric power Pk for keeping warm to the electric heater unit 10.
Further, in the heat retaining process after the temperature detected by the temperature sensor 8 exceeds 94 ° C., the control unit 7 presets the humidity detected by a humidity sensor (not shown) that detects the humidity of the humidification target space. The operation of the heater drive unit 18 is controlled so as to intermittently supply power to the humidifying heater 12 of the electric heater unit 10 so as to be maintained in the adjustment humidity range (not shown).

When the operation switch 9a and the silent mode switch 9c of the operation unit 9 are pressed, the control unit 7 performs a humidifying operation in the silent operation mode. In the silent operation mode, as shown in FIG. In the initial heating period in which the temperature detected by the temperature sensor 8 is less than 50 ° C., the heater driving unit 18 is set in the temperature raising power supply state to supply the temperature raising power Ph to the electric heater unit 10, and the temperature detected by the temperature sensor 8 is In the first period of the plosive generation suppression period of 50 ° C. or more and 70 ° C. or less, the heater driving unit 18 is set in the steam bubble suppression power supply state in order to supply the steam bubble suppression power Pm to the electric heater unit 10. After the detected temperature of the temperature sensor 8 exceeds 70 ° C. (however, the period when the detected temperature of the temperature sensor 8 is 90 ° C. or lower is the second period of the generation of the plosive sound) Electric power P To supply to the heater driving unit 18 to the thermal insulation power supply state.
Furthermore, the control unit 7 controls the electric heater unit 10 so that the humidity detected by the humidity sensor is maintained in the adjustment humidity range in the heat retention process after the temperature detected by the temperature sensor 8 exceeds 94 ° C. In order to intermittently supply power to the humidifying heater 12, the operation of the heater driving unit 18 is controlled (not shown).

That is, in the humidification operation in the normal operation mode, the heating power Ph (985 W) is supplied to the electric heater unit 10 during the temperature rising process in which the temperature detected by the temperature sensor 8 is 94 ° C. or lower after the start of heating. .
On the other hand, in the humidifying operation in the silent operation mode, the heating power Ph (985 W) is supplied to the electric heater unit 10 in the initial heating period in which the temperature detected by the temperature sensor 8 is less than 50 ° C. after the start of heating. In the first period in which the detected temperature of the temperature sensor 8 is 50 ° C. or higher and the heating temperature lowering set temperature is 70 ° C. or lower in the burst sound generation suppression period in which the detected temperature 8 is 50 ° C. or higher and 90 ° C. or lower. A steam bubble suppression power Pm (575 W) lower than the temperature raising power Ph is supplied to the heater unit 10, and the temperature detected by the temperature sensor 8 exceeds the set temperature for lowering the heating amount 70 ° C. and is a second temperature of 90 ° C. or less. In the period, the electric power for heat insulation Pk (410 W) lower than the electric power Pm for suppressing steam bubbles is supplied to the electric heater unit 10.

  The average value of the electric power supplied to the electric heater unit 10 in the burst sound generation suppression period over the first period and the second period is 460 W, which is higher than the average value of 985 W of the electric power supplied to the electric heater unit 10 in the initial heating period. small. The average value of the power supplied to the electric heater unit 10 in the second period of the plosive generation suppression period is 410 W, and the average value of the power supplied to the electric heater unit 10 in the first period of the plosive generation suppression period. Less than 575W. Here, the average value of the power supplied to the electric heater unit 10 in the first period and the second period of the plosive generation suppression period corresponds to the integrated value of the power supplied to the electric heater unit 10 during the corresponding period. It is the value divided by the duration time.

That is, in this embodiment, the plosive generation suppression period is divided into a plurality of periods. Then, the control unit 7 calculates the average value of the power supplied to the electric heater unit 10 in each of a plurality of periods (that is, the heating amount of the heating means H) on the side where the time from the start of the plosive generation suppression period elapses. The period is configured to be smaller.
In other words, the plosive generation suppression period is a first period in which the detected temperature of the temperature sensor 8 is 50 ° C. or higher and the heating temperature lowering set temperature is 70 ° C. or lower, and the detected temperature of the temperature sensor 8 is the heating temperature lowering set temperature. It is divided into two periods of the second period exceeding 70 ° C. and 90 ° C. or less. And the control part 7 is the electric power of the electric heater unit 10 (namely, heating amount of the heating means H) in the 2nd period when the detection temperature of the temperature sensor 8 is higher than the setting temperature for heating amount reduction | decrease in a plosive generation | occurrence | production suppression period. The average value of the temperature sensor 8 is configured to be smaller than the average value of the electric power of the electric heater unit 10 (that is, the heating amount of the heating means H) in the first period when the temperature detected by the temperature sensor 8 is equal to or lower than the heating temperature lowering set temperature. Has been.

  In this embodiment, the period from the end of the plosive generation suppression period to the time when the water W in the inner container 1 is saturated and boiled, that is, the temperature detected by the temperature sensor 8 exceeds 90 ° C. and 94 ° C. In the following period, the electric power supplied to the electric heater unit 10 is maintained at the heat retaining power Pk.

Next, the result of a verification test that verifies that the noise generated from the humidifier can be reduced by performing the humidification operation in the silent operation mode will be described.
In this verification test, 20 ° C. water W is stored in the inner container 1 with the maximum storage capacity, and the humidification operation is executed in both the normal operation mode and the silent operation mode at a room temperature of 20 ° C. in each mode. During the heating process, the noise generated from the humidifier was measured with a sound level meter. Further, the time required from the start of heating until the temperature detected by the temperature sensor 8 reached 100 ° C. was measured.
The noise generated from the humidifier was measured under the following conditions.
That is, the humidifier is operated by putting water of the maximum storage capacity (3.0 liters in this embodiment) into the inner container 1, and from the humidifier in the five directions of the front, back, left and right sides, and top of the humidifier. Noise is measured with a sound level meter at a position 1 m away. FIG. 8 shows measured values in the direction of the highest noise among the five directions.

  As shown in FIG. 8, in the silent operation mode, the maximum noise in the period during which the detected temperature of the temperature sensor 8 is 50 ° C. or more and 90 ° C. or less is 36.7 dB, while in the normal operation mode, The maximum noise when the detected temperature of the temperature sensor 8 is 50 ° C. or higher and 90 ° C. or lower is 45.9 dB, and the noise generated from the humidifier is reduced by performing the humidification operation in the silent operation mode. Is able to. In addition, at each temperature (50 ° C, 60 ° C, 70 ° C, 80 ° C, 90 ° C) during the generation of plosive noise, noise generated from the humidifier is reduced by performing the humidification operation in the silent operation mode. Is able to. Furthermore, while the temperature detected by the temperature sensor 8 is 70 ° C. or higher and 90 ° C. or lower, noise generated from the humidifier is particularly large, but is generated from the humidifier by performing the humidifying operation in the silent operation mode. Noise can be effectively reduced.

  Further, the time required from the heating start time until the temperature detected by the temperature sensor 8 reaches 100 ° C. is about 30 minutes in the silent operation mode and about 22 minutes in the normal operation mode. When the humidifying operation is performed in the silent operation mode, the start-up time required to bring the water W in the inner container 1 to saturation boiling is somewhat longer than when the humidifying operation is performed in the normal operation mode, but the electric heater unit 10 It is possible to suppress the rise time from becoming longer compared to the case where the power supplied to the battery is always maintained at a power (for example, 575 W) lower than the power (985 W) for the initial heating period in the silent operation mode from the start of heating. it can.

[Another embodiment]
Next, another embodiment will be described.
(A) The setting example of the plosive generation suppression period is limited to the setting example illustrated in the above embodiment, that is, when the temperature detected by the temperature sensor 8 is set to the entire period of 50 ° C. or more and 90 ° C. or less. However, it can be appropriately set as long as it is a period corresponding to the subcooled boiling state from the start of heating to the saturated boiling state. That is, the correlation between the temperature detected by the temperature sensor 8 and the magnitude of the noise (corresponding to the generation state of the steam bubble B) is, for example, the detection position and content of the temperature of the water W in the inner container 1 by the temperature sensor 8. It changes according to the ratio of the area of the heat transfer part 17 to the area of the entire bottom surface of the vessel 1. Therefore, a correlation between the detected temperature of the temperature sensor 8 and the magnitude of noise (corresponding to the state of occurrence of the steam bubble B) is obtained by experiment, and the burst sound generation suppression period is determined based on the detected temperature of the temperature sensor 8. Will be set. For example, the detected temperature of the temperature sensor 8 may be set to a part of the period of 50 ° C. or higher and 90 ° C. or lower, and is different from the period of the temperature sensor 8 detected temperature of 50 ° C. or higher and 90 ° C. or lower. A period may be set.
Specifically, as shown in FIGS. 9 and 10, the plosive generation suppression period is a period in which the temperature detected by the temperature sensor 8 is 50 ° C. or more and 90 ° C. or less, that is, a period in which noise is particularly high, that is, The temperature detected by the temperature sensor 8 may be set to a period of 70 ° C. or higher and 90 ° C. or lower (see FIG. 8).
FIG. 9 shows that the power supplied to the electric heater unit 10 is maintained at a power lower than the heating power Ph (in the other embodiment shown in FIG. 9, the warming power Pk) over the entire duration of the plosive generation suppression period. An example of the case is shown.
FIG. 10 shows the electric power of the electric heater unit 10 in the second period in which the detected temperature of the temperature sensor 8 is higher than the set temperature for lowering the heating amount (85 ° C. in another embodiment shown in FIG. 10) during the plosive generation suppression period. An example in the case where the average value is made smaller than the average value of the electric power of the electric heater unit 10 in the first period when the temperature detected by the temperature sensor 8 is equal to or lower than the heating temperature lowering set temperature is shown. Here, the average value of electric power of the electric heater unit 10 in the first period and the second period is a value obtained by dividing the integrated value of electric power supplied to the electric heater unit 10 during the corresponding period by the time of the corresponding period. is there.

(B) The form of adjusting the average value of the electric power supplied to the electric heater unit 10 during the bursting sound generation suppression period is the form illustrated in the embodiment shown in FIG. 7 and the other embodiment shown in FIG. It is not limited to the form which maintains the electric power supplied to the heater unit 10 at the constant electric power lower than the electric power of the electric heater unit 10 in the initial heating period. However, in the embodiment shown in FIG. 7 described above, when the average value of the electric power supplied to the electric heater unit 10 is reduced in two stages of the first period and the second period in the plosive generation suppression period, at each stage. This power is maintained at a constant power lower than the power during the initial heating period.

For example, as shown in FIGS. 10 to 14, the electric power of the electric heater unit 10 is set to a high set power Pb that is set to be equal to or lower than the temperature raising power Ph in the initial heating period. A mode in which a cycle consisting of a high power period Tb to be adjusted and a low power period Ts in which the power of the electric heater unit 10 is adjusted to a low setting power Ps lower than the high setting power Pb or zero is repeated (hereinafter, cycle adjustment mode) The power supplied to the electric heater unit 10 is adjusted so that the duty ratio (Tb / (Tb + Ts)) of the high power period Tb, the high set power Pb, and the low set power Ps. As an embodiment for adjusting the average value of the power supplied to the electric heater unit 10 during the plosive generation suppression period by adjusting at least one of the above Good.
In this case, the electric heater unit 10 may be configured by a single electric heater, and the heater driving unit 18 may be configured to be capable of adjusting the power supplied to the electric heater unit 10 in a plurality of steps or continuously. The electric heater unit 10 may be configured by three or more electric heaters, and the heater driving unit 18 may be configured to be able to change the number and combination of electric heaters to be heated.
11 to 14 are also examples in the case of reducing the average value of the power supplied to the electric heater unit 10 in two stages of the first period and the second period in the plosive generation suppression period, as in FIG. It is.

  Note that FIG. 10 shows the adjustment of the average value of the power supplied to the electric heater unit 10 in the cycle adjustment mode in the first period of the plosive generation suppression period, and the power supplied to the electric heater unit 10 in the second period. Is maintained at a lower power than the heating power Ph. Moreover, FIGS. 11-14 shows the example in the case of adjusting the average value of the electric power supplied to the electric heater unit 10 with a cycle adjustment form in both the 1st period and 2nd period of a plosive generation | occurrence | production suppression period.

(B-1) In the cycle adjustment form shown in FIG. 10, the high set power Pb is set to the same power as the temperature raising power Ph, and the low set power Ps is set to the same power as the heat retaining power Pk. .

(B-2) In FIG. 11, the low set power Ps is set to be lower in the second period than in the first period, and the duty ratio and the high set power Pb in the high power period Tb are set to the first period and the second period. By setting the same in the period, the average value of the electric power supplied to the electric heater unit 10 is adjusted so that the second period is smaller than the first period.
Incidentally, the high set power Pb is set to the same power as the temperature raising power Ph in the first period and the second period, and the low set power Ps in the first period is set to the temperature raising power Ph and the temperature keeping power Pk. The low set power Ps in the second period is set to the same power as the heat retaining power Pk.

(B-3) In FIG. 12, the high set power Pb is set so that the second period is lower than the first period, and the duty ratio and the low set power Ps of the high power period Tb are set to the first period and the second period. By setting the same in the period, the average value of the electric power supplied to the electric heater unit 10 is adjusted so that the second period is smaller than the first period.
Incidentally, the low set power Ps is set to the power between the temperature rising power Ph and the heat retaining power Pk in both the first period and the second period, and the high set power Pb in the first period is set to the power rising power Ph. Is set to the same power.

(B-4) In FIG. 13, the duty ratio of the high power period Tb, the high set power Pb, and the low set power Ps are all supplied to the electric heater unit 10 by making them different in the first period and the second period. The average value of the power to be adjusted is adjusted so that the second period is smaller than the first period.
Incidentally, the duty ratio and the low set power Ps of the high power period Tb are set so that the second period is smaller than the first period, and the high set power Pb is higher in the second period than in the first period. Also, the average value of the power in each of the first period and the second period is adjusted so as to increase.
The high set power Pb in the second period is set to the same power as the temperature raising power Ph, and the low set power Ps in the second period is set to the power between the temperature raising power Ph and the heat retaining power Pk. Then, each of the high set power Pb and the low set power Ps in the first period is set to a power between the high set power Pb and the low set power Ps in the second period.

(B-5) In FIG. 14, the high set power Pb and the low set power Ps are set so that the second period is smaller than the first period, and the duty ratio of the high power period Tb is set to the first period. In the second period, the average value of the power supplied to the electric heater unit 10 is adjusted to be smaller in the second period than in the first period.
Incidentally, the high set power Pb in the first period is set to the power between the temperature raising power Ph and the heat retaining power Pk, and the low set power Ps in the first period and the high set power Pb in the second period are both set. The power is set to the same power as the heat retaining power Pk, and the low set power Ps in the second period is set to 0, that is, the heating operation is stopped.

(C) In the above embodiment, the average value of the power supplied to the electric heater unit 10 is reduced in two stages of the first period and the second period in the plosive generation suppression period, but in three or more stages, The average value of the power supplied to the electric heater unit 10 may be reduced, or the average value of the power may be reduced by continuously reducing the power supplied to the electric heater unit 10.

(D) In the above embodiment, the period from the end of the plosive generation suppression period until the water W in the inner container 1 is in a saturated boiling state (in the above embodiment, the temperature detected by the temperature sensor 8 is 90 ° C. In this period, the electric power supplied to the electric heater unit 10 is maintained at the heat retaining power Pk. However, in this period, the electric power supplied to the electric heater unit 10 is maintained at the heat insulating power Pk. You may make it maintain higher electric power (for example, electric power Ph for temperature rising). In this way, it is possible to further reduce the time required to bring the water W in the inner container 1 to saturation boiling.

(E) To set the plosive generation suppression period based on the temperature detected by the temperature sensor 8, in the above embodiment, the plosive generation suppression period is set based on the temperature detected by the temperature sensor 8 itself. It is not limited. For example, the plosive generation suppression period may be set based on the rate of increase of the temperature detected by the temperature sensor 8.

(F) The configuration for setting the plosive generation suppression period is not limited to the configuration in the above embodiment, that is, the configuration set based on the temperature detected by the temperature sensor 8. For example, a noise meter that measures the noise generated from the humidifier may be provided, and the burst sound generation suppression period may be set based on the measurement information of the noise meter.

(G) The installation form of the heat transfer part 17 is not limited to the form illustrated in the above embodiment, and, for example, according to the outer shape of the heating means H, the arrangement form of the heating means H with respect to the inner container 1, etc. Can be changed.
For example, when the heating means H is constituted by a sheathed heater and the sheathed heater is provided in the inner container 1 in an exposed state, the outer peripheral surface of the sheathed heater becomes the heat transfer section 17.
Further, when the long electric heater is arranged around the entire bottom portion of the inner container 1 and disposed below the bottom portion of the inner container 1, substantially the entire bottom surface of the inner container 1 becomes the heat transfer section 17.

(H) A specific example of the heating means H is not limited to the electric heater unit 10 as in the above embodiment. For example, when the heating unit H is configured by an electric heating unit as in the above-described embodiment, for example, a sheathed heater or an electromagnetic induction heating (so-called IH) type is adopted as the electric heating unit. be able to. The heating means H may be constituted by a gas burner.

(I) Examples of the liquid heater to which the present invention is applicable are not limited to the humidifiers exemplified in the above embodiment, and may be, for example, an electric kettle or an electric pot. Incidentally, the electric kettle includes a kettle body including an inner container and an electric heater unit, and a power supply plate that supplies power to the electric heater unit of the kettle body.

  As described above, to provide a liquid heater that can reduce the noise generated in the temperature rising process until saturation boiling while preventing the rise time until the liquid in the storage portion is saturated to boiling. Can do.

1 Inner container (reservoir)
7 Control unit (control means)
8 Temperature sensor (temperature detection means)
10 Electric heater unit (electric heating means)
17 Heat transfer part B Steam bubble H Heating means W Water (liquid)

Claims (2)

A storage unit that stores the liquid to be heated, a heating unit that heats the liquid in the storage unit , a control unit that adjusts a heating amount of the heating unit, and a temperature detection unit that detects the temperature of the liquid in the storage unit a liquid heater with bets,
In the temperature rising process until the liquid in the storage unit is heated to saturation boiling by the heating unit, the vapor bubbles generated in the heat transfer unit that transfers the heat from the heating unit to the liquid in the storage unit are The entire duration of the period from when the temperature detected by the temperature detecting means reaches 50 ° C. until the temperature detected by the temperature detecting means reaches 90 ° C. Set to some ,
The plosive generation suppression period is divided into a plurality of periods,
The control means makes the average value of the heating amount of the heating means in each of the plurality of periods smaller as the time on the side from the start of the plosive generation suppression period decreases, and the plosive generation suppression period The liquid heater which makes the average value of the heating amount of the heating means smaller than the average value of the heating amount of the heating means in the initial heating period until the burst sound generation suppression period. The control means is configured to calculate an average value of the heating amount of the heating means during a period in which the temperature detected by the temperature detecting means is higher than a predetermined set temperature during the burst sound generation suppression period, and the temperature detected by the temperature detecting means The liquid heater according to claim 1 , wherein the liquid heater is set to be smaller than an average value of a heating amount of the heating unit in a period of a set temperature or lower.

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