JP6958253B2 - Electric boiler - Google Patents

Description

The present invention relates to an electric boiler.

An electric boiler that heats water with an electric heater as disclosed in Patent Document 1 is known.

Japanese Unexamined Patent Publication No. 2010-169356

Contact with water can cause scale to adhere to the surface of the electric heater. In addition, there is a possibility that the surface of the electric heater does not come into contact with water. If the scale is left on the surface of the electric heater, for example, the temperature of the electric heater may rise locally or corrode. Further, if the surface of the electric heater is left in a state where it does not come into contact with water, the electric heater may overheat. As a result, the performance of the electric boiler may deteriorate.

An aspect of the present invention is to provide an electric boiler capable of suppressing deterioration in performance.

According to an aspect of the present invention, there is provided an electric boiler including a water pipe, an electric heater arranged inside the water pipe, and a temperature sensor arranged in a heat generating region on the surface of the electric heater.

According to an aspect of the present invention, an electric boiler capable of controlling the temperature of an electric heater is provided.

FIG. 1 is a front view schematically showing an example of an electric boiler according to the present embodiment. FIG. 2 is a side view schematically showing an example of the electric boiler according to the present embodiment. FIG. 3 is a side sectional view showing an example of the heater device according to the present embodiment. FIG. 4 is a functional block diagram showing an example of the electric boiler according to the present embodiment. FIG. 5 is a flowchart showing an example of the control method of the electric boiler according to the present embodiment.

Hereinafter, embodiments according to the present invention will be described with reference to the drawings, but the present invention is not limited thereto. The components of the embodiments described below can be combined as appropriate. In addition, some components may not be used.

In the present embodiment, a three-dimensional Cartesian coordinate system is defined, and the positional relationship of each part will be described based on the three-dimensional Cartesian coordinate system. The direction parallel to the X-axis in the horizontal plane is defined as the X-axis direction. The direction parallel to the Y-axis in the horizontal plane orthogonal to the X-axis is defined as the Y-axis direction. The direction parallel to the Z axis orthogonal to the horizontal plane is defined as the Z axis direction.

[Electric boiler]
FIG. 1 is a front view schematically showing an example of the electric boiler 1 according to the present embodiment. FIG. 2 is a side view schematically showing an example of the electric boiler 1 according to the present embodiment. Each of FIGS. 1 and 2 shows a part of the electric boiler 1 in cross section.

As shown in FIGS. 1 and 2, the electric boiler 1 includes a water supply device 2, a lower pipe gathering 3 connected to the water supply device 2, a plurality of water pipes 4 connected to the lower pipe gathering 3, and a plurality of water pipes. A plurality of rising pipes 5 connected to each of 4, an upper pipe gathering 6 connected to the rising pipe 5, a heater device 7 having an electric heater 71 arranged inside the water pipe 4, and a surface of the electric heater 71. A temperature sensor 8 arranged in the heat generation region FA, a water level detection device 9 for detecting the water level of the water pipe 4, a control device 10 for controlling the electric boiler 1, a notification device 11 for notifying notification information, and a heater device 7 A power supply 12 for supplying power to the power supply 12 is provided.

The water supply device 2 supplies water to the water pipe 4 via the lower pipe gathering 3. The water supply device 2 has a water supply pipe 21 connected to the lower pipe gathering 3, a water supply pump 22 arranged in the water supply pipe 21, and a water supply valve 23 arranged in the water supply pipe 21. By the operation of the water supply pump 22, water is supplied to the lower pipe gathering 3 via the water supply pipe 21. Water is supplied to the water pipe 4 by supplying water to the lower pipe gathering 3. The water supply device 2 can adjust the amount of water supplied per unit time with respect to the lower pipe gathering 3. In the present embodiment, the control device 10 adjusts the amount of water supplied per unit time with respect to the lower pipe gathering 3 by adjusting the amount of rotation of the water supply pump 22 per unit time. By adjusting the amount of water supplied to the lower pipe group 3, the amount of water supplied per unit time to the water pipe 4 is adjusted. When the water supply valve 23 functions as a flow rate adjusting valve, the water supply valve 23 may adjust the amount of water supplied per unit time with respect to the lower pipe gathering 3.

The lower pipe gathering 3 accommodates the water supplied from the water supply device 2. The lower pipe gathering 3 is a container having an internal space 3H in which water is housed. The lower pipe gathering 3 distributes the water supplied from the water supply device 2 to each of the plurality of water pipes 4. The water supplied from the water supply device 2 to the lower pipe group 3 is supplied to each of the plurality of water pipes 4. Further, the drainage pipe 24 is connected to the lower part of the lower pipe gathering 3. A drain valve 25 is arranged in the drain pipe 24. When the drain valve 25 is opened, at least a part of the water contained in the internal space 3H of the lower pipe gathering 3 is discharged through the drain pipe 24.

The water pipe 4 circulates water from the lower pipe gathering 3. The water pipe 4 is a cylindrical member having a water flow path. The water pipe 4 is arranged so that the central axis of the water pipe 4 and the Z axis are parallel to each other. The lower end of the water pipe 4 and the upper part of the lower pipe gathering 3 are connected. A plurality of water pipes 4 are arranged at intervals in the X-axis direction. Each of the plurality of water pipes 4 is connected to the lower pipe gathering 3.

The electric heater 71 is arranged inside the water pipe 4. The electric heater 71 is a rod-shaped member. The surface of the electric heater 71 faces the inner surface of the water pipe 4 via a gap. The water from the lower pipe gathering 3 is supplied between the inner surface of the water pipe 4 and the surface of the electric heater 71. The surface of the electric heater 71 comes into contact with the water supplied to the inside of the water pipe 4. When the surface of the electric heater 71 comes into contact with water, the water is heated and steam is generated.

The temperature sensor 8 is arranged in the heat generation region FA on the surface of the electric heater 71. The temperature sensor 8 detects the temperature of the heat generation region FA of the electric heater 71. The temperature sensor 8 is arranged above the heat generation region FA of the electric heater 71.

The riser pipe 5 circulates the steam generated by the water pipe 4. The riser pipe 5 is a cylindrical member having a steam flow path. The ascending pipe 5 connects the water pipe 4 and the upper pipe gathering 6. The steam generated in the water pipe 4 is supplied to the upper pipe gathering 6 via the rising pipe 5. The lower end of the riser pipe 5 and the upper part of the water pipe 4 are connected. The upper end of the ascending pipe 5 and the lower part of the upper pipe gathering 6 are connected. A plurality of risers 5 are provided so as to be connected to each of the plurality of water pipes 4. Each of the plurality of rising pipes 5 is connected to the upper pipe gathering 6.

As shown in FIG. 2, the positions of the lower pipe gathering 3 and the water pipe 4 and the position of the upper pipe gathering 6 are different in the Y-axis direction. A part of the riser pipe 5 is bent. The lower end of the riser pipe 5 is connected to the −Y side side surface of the upper part of the water pipe 4. The upper end of the ascending pipe 5 is connected to the lower part of the upper pipe gathering 6.

The upper pipe gathering 6 accommodates the steam supplied from the rising pipe 5. The upper pipe gathering 6 is a container having an internal space 6H in which steam is housed. The upper pipe gathering 6 collects the steam supplied from each of the plurality of rising pipes 5. Further, the steam pipe 26 is connected to the upper part of the upper pipe gathering 6. A steam valve 27 is arranged in the steam pipe 26. When the steam valve 27 is opened, at least a part of the steam contained in the internal space 6H of the upper pipe gathering 6 is discharged through the steam pipe 26.

The water level detecting device 9 detects the water level between the inner surface of the water pipe 4 and the surface of the electric heater 71. The water level refers to the position of the surface of water in the Z-axis direction. The water level detection device 9 includes a detection container 91, a plurality of electrode rods 92 arranged in the detection container 91, a lower communication pipe 93 connecting the detection container 91 and the lower pipe gathering 3, and the detection container 91 and the upper pipe gathering. It has an upper communication pipe 94 for connecting to 6.

The internal space 91H of the detection container 91 is connected to the internal space 3H of the lower pipe gathering 3 via the lower communication pipe 93. The internal space 91H of the detection container 91 is connected to the internal space 6H of the upper pipe gathering 6 via the upper communication pipe 94. The lower communication pipe 93 connects the lower part of the detection container 91 and the upper part of the lower pipe gathering 3. The upper communication pipe 94 connects the upper part of the detection container 91 and the lower part of the upper pipe gathering 6.

Water is contained in the detection container 91. The water level of the detection container 91 and the water level of the water pipe 4 are substantially equal to each other. The water level detection device 9 can detect the water level of the water pipe 4 by detecting the water level of the detection container 91.

The plurality of electrode rods 92 are arranged in the internal space 91H of the detection container 91. In this embodiment, the electrode rod 92 includes three electrode rods 92A, 92B, 92C. A plurality of electrode rods 92 may be provided, and for example, four or more electrode rods may be provided.

The electrode rod 92 is a rod-shaped member made of a conductive material. The upper end of the electrode rod 92 is held by the upper lid of the detection container 91 via an insulating material. The lower end of the electrode rod 92 is separated from the detection container 91.

The electrode rods 92A, 92B, 92C are held in the detection container 91 so that the positions of the lower ends of the electrode rods 92A, 92B, 92C in the Z-axis direction are different. In the present embodiment, among the electrode rods 92A, 92B, and 92C, the lower end portion of the electrode rod 92A is arranged at the highest position, and the lower end portion of the electrode rod 92B is arranged at the highest position next to the lower end portion of the electrode rod 92A. , The lower end of the electrode rod 92C is arranged at the lowest position.

The detection container 91 is made of a conductive material. The detection container 91 functions as a common electrode for the plurality of electrode rods 92. When the water contained in the detection container 91 comes into contact with the lower end of the electrode rod 92, the detection container 91 and the electrode rod 92 are energized via water.

The water level detection device 9 detects water with the electrode rod 92. The water level detection device 9 determines that the electrode rod 92 and water have come into contact with each other when an electric current flows through the electrode rod 92.

The water level detecting device 9 detects the water level of the detection container 91 based on the presence or absence of a current flowing through each of the plurality of electrode rods 92. For example, when a current is flowing through all of the electrode rods 92A, 92B, and 92C, the control device 10 determines that the water level of the detection container 91 is higher than the lower end of the electrode rod 92A. When a current flows through the electrode rods 92B and 92C and no current flows through the electrode rods 92A, the control device 10 determines that the water level of the detection container 91 is higher than the lower end portion of the electrode rod 92B and lower than the lower end portion of the electrode rod 92A. Is determined. When a current flows through the electrode rods 92C and no current flows through the electrode rods 92A and 92B, the control device 10 determines that the water level of the detection container 91 is higher than the lower end portion of the electrode rod 92C and lower than the lower end portion of the electrode rod 92B. Is determined. When no current is flowing through all of the electrode rods 92A, 92B, and 92C, the control device 10 determines that the water level of the detection container 91 is lower than the lower end of the electrode rod 92C.

In the Z-axis direction, the position of the lower end of the electrode rod 92C and the position of the upper end of the heat generating region FA of the electric heater 71 are substantially the same. When an electric current flows through the electrode rod 92C and the electrode rod 92C detects water, the control device 10 determines that the entire heat generating region FA of the electric heater 71 is immersed in the water of the water pipe 4. On the other hand, when no current flows through the electrode rod 92C and the electrode rod 92C does not detect water, at least a part of the control device 10 including the upper end portion of the heat generating region FA of the electric heater 71 is not immersed in the water of the water pipe 4. Is determined.

Based on the detection result of the water level detection device 9, the water supply device 2 supplies water to the water pipe 4 so that the water level of the water pipe 4 is maintained above the heat generation region FA of the electric heater 71. In the present embodiment, when the electrode rods 92B and 92C detect water and the electrode rods 92A do not detect water, the control device 10 operates the water supply pump 22 to supply water. When all of the electrode rods 92A, 92B, and 92C detect water, the control device 10 stops the operation of the water supply pump 22 to stop the water supply. As a result, the water level of the water pipe 4 is maintained at a position between the lower end of the electrode rod 92A and the lower end of the electrode rod 92B. By maintaining the water level of the water pipe 4 between the lower end of the electrode rod 92A and the lower end of the electrode rod 92B, the entire heat generating region FA of the electric heater 71 can be immersed in water.

[Electric heater and temperature sensor]
FIG. 3 is a side sectional view showing an example of the heater device 7 according to the present embodiment. As shown in FIGS. 1, 2, and 3, the heater device 7 is connected to an electric heater 71 arranged inside the water pipe 4, a flange 72 supported at the upper end of the water pipe 4, and a power supply 12. It has a connector 73.

The electric heater 71 is a rod-shaped member. In the present embodiment, the electric heater 71 is a cartridge heater. The electric heater 71 has a surface facing the inner surface of the water pipe 4 via a gap. The electric heater 71 is inserted into the water pipe 4 through the opening at the upper end of the water pipe 4. The flange 72 is fixed to the upper end of the water pipe 4. The heater device 7 is removable from the water pipe 4.

The surface of the electric heater 71 has a heat generating region FA and a non-heating region NA. The non-heat-generating region NA is arranged above the heat-generating region FA. The heat generation region FA includes the lower end of the surface of the electric heater 71 facing the inner surface of the water pipe 4. The non-heating region NA includes the upper end of the surface of the electric heater 71 facing the inner surface of the water pipe 4. In the Z-axis direction, the dimension of the heat generating region FA is larger than the dimension of the non-heating region NA. In the Z-axis direction, the boundary EG between the heat generating region FA and the non-heating region NA is arranged above (+ Z side) from the intermediate portion of the surface of the electric heater 71 facing the inner surface of the water pipe 4.

As shown in FIG. 3, the electric heater 71 includes a core material 74, a heating wire 75 arranged around the core material 74, an accommodating member 76 accommodating the core material 74 and the heating wire 75, and an accommodating member 76. It has a powder 77 to be filled between the core material 74 and the heating wire 75.

The core material 74 is formed of an insulating material such as ceramics. The heating wire 75 is wound around the core material 74 in a coil shape. The accommodating member 76 is a cylindrical member and is made of a metal such as stainless steel. The powder 77 is formed of an insulating material such as magnesium oxide (MgO).

The core material 74 is a cylindrical member. A pair of electrode wires 78 are arranged inside the core material 74. At least a part of the electrode wire 78 is arranged in the hole provided in the core material 74. The tip of the electrode wire 78 and the heating wire 75 are connected. The opening at the upper end of the accommodating member 76 is closed by the sealing member 79. The flange 72 is arranged at the upper end of the accommodating member 76.

The electrode wire 78 is connected to the power supply 12 via the connector 73. When a current is supplied from the power supply 12 to the heating wire 75 via the electrode wire 78, the heating wire 75 generates heat.

The heat generating region FA corresponds to a portion where the heating wire 75 is provided. The non-heating region NA corresponds to a portion where the heating wire 75 is not provided.

The electric heater 71 is inserted into the water pipe 4 through the opening at the upper end of the water pipe 4 so that the non-heating region NA is arranged above the heat generating region FA. After the electric heater 71 is inserted into the water pipe 4, the flange 72 and the upper end portion of the water pipe 4 are fixed.

The temperature sensor 8 is arranged above the heat generation region FA. The upper part of the heat generation region FA means a portion above (+ Z side) from the middle portion of the heat generation region FA in the Z-axis direction. In the present embodiment, the temperature sensor 8 is arranged in the vicinity of the boundary EG between the heat generation region FA and the non-heat generation region NA. That is, the temperature sensor 8 is arranged at the upper end of the heat generation region FA.

In the present embodiment, one temperature sensor 8 is provided for one electric heater 71. A plurality of temperature sensors 8 may be provided in one electric heater 71. The temperature sensor 8 may be provided in one of the plurality of electric heaters 71.

One electric heater 71 may be arranged in the water pipe 4, or an aggregate of a plurality of electric heaters 71 may be arranged in the water pipe 4. When an aggregate of a plurality of electric heaters 71 is arranged in the water pipe 4, the current supplied from the power supply 12 is supplied to each of the plurality of electric heaters 71 by connecting the plurality of electric heaters 71 to the connector 73. Will be done. The electric heater 71 may be a sheathed heater.

[Control device]
FIG. 4 is a functional block diagram showing an example of the electric boiler 1 according to the present embodiment. As shown in FIG. 4, the electric boiler 1 has a control device 10. The control device 10 is connected to each of the temperature sensor 8, the water level detection device 9, the water supply device 2, the notification device 11, and the power supply 12. As shown in FIGS. 1 and 2, in the present embodiment, three electric heaters 71 and three temperature sensors 8 are provided.

The notification device 11 notifies the user of the electric boiler 1 of the notification information. As the notification device 11, at least one of a display device, a light emitting device, and a sound output device is exemplified. Display devices include flat panel displays such as liquid crystal displays (LCDs) or organic electroluminescence displays (OELDs). The light emitting device includes a light source such as a light emitting diode (LED). The sound output device includes a siren or a voice output device capable of generating a warning sound. The notification device 11 notifies the user of the electric boiler 1 of notification information using at least one of the display data displayed on the display device, the light emitted from the light emitting device, and the sound output from the sound output device. do.

The control device 10 includes a computer system. The control device 10 includes an arithmetic processing device 10A including a processor such as a CPU (Central Processing Unit), a volatile memory such as a RAM (Random Access Memory), and a non-volatile memory such as a ROM (Read Only Memory). It has a storage device 10B and an input / output interface 10C including an input / output circuit capable of transmitting / receiving signals or data.

The arithmetic processing unit 10A includes a temperature data acquisition unit 101, a water level data acquisition unit 102, a determination unit 103, a water supply control unit 104, a notification control unit 105, and an electric heater control unit 106.

The storage device 10B has a first specified value storage unit 107 and a second specified value storage unit 108.

The temperature data acquisition unit 101 acquires temperature data indicating the detected value of the temperature sensor 8. The water level data acquisition unit 102 acquires water level data indicating a detection value of the water level detection device 9.

The determination unit 103 determines whether or not scale is attached to the surface of the electric heater 71 based on the detected value of the temperature sensor 8. Further, the determination unit 103 determines whether or not the electric heater 71 is overheated based on the detected value of the temperature sensor 8.

The scale refers to a precipitate of a hardness component contained in water. The surface of the electric heater 71 comes into contact with water. Therefore, scale may adhere to the surface of the electric heater 71. When scale adheres to the heat generation region FA of the electric heater 71, heat dissipation from the heat generation region FA is hindered. As a result, the temperature of the electric heater 71 rises. For example, even if the supply conditions of the electric power supplied from the power supply 12 to the electric heater 71 are constant and the water supply conditions including the temperature of the water supplied to the water pipe 4 and the amount of water supplied per unit time are constant, the scale is scaled to the heat generation region FA. The temperature of the surface of the electric heater 71 is different between the state in which the electric heater 71 is attached and the state in which the electric heater 71 is not attached. The determination unit 103 can determine whether or not scale is attached to the surface of the electric heater 71 based on the detected value of the temperature sensor 8.

When the supply condition of the electric power supplied from the power source 12 to the electric heater 71 is constant and the water supply condition to the water pipe 4 is constant, the electric heater 71 when the scale does not adhere to the heat generation region FA of the electric heater 71. The temperature of the electric heater 71 and the temperature of the electric heater 71 when the scale is attached to the heat generation region FA of the electric heater 71 can be derived in advance from, for example, a preliminary experiment or a simulation experiment. That is, the temperature of the electric heater 71 when the scale is attached to the heat generation region FA of the electric heater 71 and the temperature of the electric heater 71 when the scale is not attached to the heat generation region FA of the electric heater 71 are known data. Is. As an example, in a state where the entire heat generating region FA is immersed in water, the temperature of the electric heater 71 when no scale is attached to the heat generating region FA of the electric heater 71 is 170 [° C.], and the electric heater 71. The temperature of the electric heater 71 when the scale is attached to the heat generation region FA of the above is 185 [° C.].

In the present embodiment, the temperature of the electric heater 71 when the scale is attached to the heat generation region FA of the electric heater 71 is derived in advance and stored in the first specified value storage unit 107 as the first specified value. The first specified value is, for example, 185 [° C.]. When the detection value of the temperature sensor 8 is 170 [° C.], which is the reference temperature, the determination unit 103 determines that the scale does not adhere to the surface of the electric heater 71, and the detection value of the temperature sensor 8 is the first definition. When the value reaches 185 [° C.], it is determined that the scale is attached to the surface of the electric heater 71.

Further, for example, due to an abnormality of the water supply pump 22, the water level of the water pipe 4 may be lower than the boundary EG, and at least a part of the heat generating region FA of the electric heater 71 may not come into contact with water. If the electric heater 71 is left in a state where the heat generating region FA of the electric heater 71 does not come into contact with water while the electric power is being supplied from the power supply 12 to the electric heater 71, the electric heater 71 overheats. The determination unit 103 can determine whether or not the electric heater 71 is overheated, that is, whether or not the water level of the water pipe 4 is lower than the boundary EG, based on the detected value of the temperature sensor 8.

When the supply conditions of the electric power supplied from the power source 12 to the electric heater 71 are constant, the temperature of the electric heater 71 when water is in contact with the heat generation region FA of the electric heater 71, and the heat generation region of the electric heater 71. The temperature of the electric heater 71 when water is not in contact with the FA can be derived in advance from, for example, a preliminary experiment or a simulation experiment. That is, the temperature of the electric heater 71 when water is in contact with the heat generation region FA of the electric heater 71 and the temperature of the electric heater 71 when water is not in contact with the heat generation region FA of the electric heater 71 are known data. be. As an example, the temperature of the electric heater 71 when the heat generating region FA is not in contact with water is 200 [° C.] or higher.

In the present embodiment, the temperature of the electric heater 71 when water is not in contact with the heat generation region FA of the electric heater 71 is derived in advance and stored in the second specified value storage unit 108 as the second specified value. The second specified value is, for example, 200 [° C.]. When the detection value of the temperature sensor 8 reaches 200 [° C.], which is the second specified value, the determination unit 103 overheats the electric heater 71, that is, the water level of the water pipe 4 drops below the boundary EG. It is determined that water is not in contact with at least a part of the heat generating region FA.

The water supply control unit 104 controls the water supply pump 22 of the water supply device 2 so that the water level of the water pipe 4 is maintained above the heat generation region FA of the electric heater 71 based on the detection value of the water level detection device 9. Output a signal. When the electrode rod 92C detects water and the electrode rods 92A and 92B do not detect water, the water supply control unit 104 outputs a control signal for operating the water supply pump 22. As a result, the water level of the water pipe 4 is maintained above the lower end of the electrode rod 92C. By maintaining the water level of the water pipe 4 above the lower end of the electrode rod 92C, the entire heat generating region FA of the electric heater 71 can be immersed in water.

The notification control unit 105 outputs a control signal for controlling the notification device 11 based on the detected value of the temperature sensor 8. In the present embodiment, the notification control unit 105 outputs a control signal for operating the notification device 11 when the determination unit 103 determines that the scale is attached to the heat generation region FA of the electric heater 71. When the notification device 11 includes a display device, the notification control unit 105 causes the display device to display display data for notifying that the scale may be attached to the surface of the electric heater 71. The display data may be character data or image data. When the notification device 11 includes a light emitting device, the notification control unit 105 emits light from the light emitting device to notify that the scale may be attached to the surface of the electric heater 71. Further, when the notification device 11 includes a sound output device, the notification control unit 105 generates a warning sound from the sound output device to notify that the scale may be attached to the surface of the electric heater 71. ..

The electric heater control unit 106 outputs a control signal for controlling the power supply 12 based on the detected value of the temperature sensor 8. In the present embodiment, the electric heater control unit 106 outputs a control signal for stopping the operation of the electric heater 71 when the determination unit 103 determines that the electric heater 71 is overheated. That is, when the determination unit 103 determines that the electric heater 71 is overheated, the electric heater control unit 106 outputs a control signal for stopping the supply of electric power to the electric heater 71 to the power supply 12.

[Control method for electric boiler]
FIG. 5 is a flowchart showing an example of a control method of the electric boiler 1 according to the present embodiment. The water supply control unit 104 operates the water supply device 2 to start water supply to the lower pipe gathering 3 (step S1). The water supply control unit 104 controls the water supply device 2 so that the water level of the water pipe 4 is maintained above the heat generation region FA of the electric heater 71 based on the detection value of the water level detection device 9.

Further, the electric heater control unit 106 operates the power supply 12 to start supplying electric power to the electric heater 71 (step S2). When the electric heater 71 is operated while the entire heat generating region FA is immersed in water, the water is heated and steam is generated.

The temperature data acquisition unit 101 monitors the detected value of the temperature sensor 8. The determination unit 103 determines whether or not the detection value of the temperature sensor 8 is equal to or greater than the first specified value (step S3).

In step S3, when it is determined that the detected value of the temperature sensor 8 is less than the first specified value (step S3: No), the determination unit 103 determines that the electric heater 71 is normal (step S4), and steps. Return to the process of S3. In the present embodiment, the normal state of the electric heater 71 means that the scale is not attached to the heat generation region FA of the electric heater 71 and the entire heat generation region FA is immersed in water.

When it is determined in step S3 that the detected value of the temperature sensor 8 is equal to or higher than the first specified value (step S3: Yes), the determination unit 103 determines whether or not the detected value of the temperature sensor 8 is equal to or higher than the second specified value. Determine (step S5).

When it is determined in step S5 that the detected value of the temperature sensor 8 is less than the second specified value (step S5: No), the determination unit 103 determines that the scale is attached to the heat generation region FA of the electric heater 71. (Step S6).

When it is determined that the scale is attached to the heat generation region FA of the electric heater 71, the notification control unit 105 outputs a control signal for operating the notification device 11 (step S7).

By operating the notification device 11, the user of the electric boiler 1 can recognize that the scale may be attached to the electric heater 71. The user of the electric boiler 1 can perform maintenance of the electric heater 71, for example.

When it is determined in step S5 that the detected value of the temperature sensor 8 is equal to or higher than the second specified value (step S5: Yes), the determination unit 103 determines that the electric heater 71 is overheated (step S8).

When it is determined that the electric heater 71 is overheated, the notification control unit 105 outputs a control signal for operating the notification device 11. The notification control unit 105 outputs a control signal so that the notification device 11 operates in a notification mode different from the notification mode in step S7. Further, when it is determined that the electric heater 71 is overheated, the electric heater control unit 106 outputs a control signal for stopping the operation of the electric heater 71 (step S9).

By operating the notification device 11, the user of the electric boiler 1 can recognize that the electric heater 71 is overheated. Further, by forcibly stopping the operation of the electric heater 71, an excessive temperature rise of the electric heater 71 is suppressed.

[effect]
As described above, according to the present embodiment, the temperature of the electric heater 71 can be controlled by providing the temperature sensor 8 in the heat generating region FA on the surface of the electric heater 71. Further, the arithmetic processing unit 10A can determine the presence or absence of an abnormality in the electric heater 71 based on the detected value of the temperature sensor 8. In the present embodiment, the abnormality of the electric heater 71 means that the scale is attached to the heat generation region FA of the electric heater 71, or that at least a part of the heat generation region FA is not in contact with water. Say both. When an abnormality occurs in the electric heater 71, measures for suppressing deterioration of the performance of the electric heater 71, such as maintenance of the electric heater 71 or stopping of operation of the electric heater 71, can be taken.

Further, in the present embodiment, the temperature sensor 8 is arranged above the heat generation region FA. As a result, the temperature sensor 8 can quickly detect the overheating of the electric heater 71 even when the water level of the water pipe 4 is slightly lowered from the boundary EG. For example, when the temperature sensor 8 is arranged below the heat generation region FA, if the water level of the water pipe 4 is slightly lowered from the boundary EG, the heat generation region FA in which the temperature sensor 8 and the temperature sensor 8 are arranged is water. Since it is immersed in water, it may be difficult to quickly detect a state in which the upper part of the heat generating region FA is not in contact with water. In the present embodiment, since the temperature sensor 8 is arranged above the heat generation region FA, the heat generation in which the temperature sensor 8 and the temperature sensor 8 are arranged is generated only when the water level of the water pipe 4 is slightly lowered from the boundary EG. The region FA is in a state where it does not come into contact with water. Therefore, the temperature sensor 8 can quickly detect a state in which the upper part of the heat generating region FA is not in contact with water.

Further, according to the present embodiment, water is supplied from the water supply device 2 to the water pipe 4 so that the water level of the water pipe 4 is maintained above the heat generation region FA of the electric heater 71. As a result, overheating of the electric heater 71 is suppressed.

Further, in the present embodiment, the temperature sensor 8 functions as a scale presence / absence sensor that detects whether or not scale is attached to the surface of the electric heater 71. If the scale is left on the surface of the electric heater 71, for example, the temperature of the electric heater 71 may rise locally or be corroded. According to this embodiment, the presence or absence of scale can be easily determined based on the detected value of the temperature sensor 8. When the scale is detected, deterioration of the performance of the electric boiler 1 can be suppressed by taking appropriate measures such as maintenance of the electric heater 71. Further, when it is determined that the scale is attached, the notification device 11 is activated, so that the user of the electric boiler 1 can promptly take appropriate measures.

Further, in the present embodiment, the temperature sensor 8 functions as an overheat presence / absence sensor that detects whether or not the electric heater 71 is overheated. If the electric heater 71 is left in an overheated state, for example, the electric heater 71 may break down. According to this embodiment, the presence or absence of overheating can be easily determined based on the detected value of the temperature sensor 8. When overheating is detected, deterioration of the performance of the electric boiler 1 can be suppressed by taking appropriate measures such as stopping the operation of the electric heater 71. Further, when it is determined that the electric heater 71 is overheated, the operation of the electric heater 71 is forcibly stopped, so that the failure of the electric heater 71 can be suppressed.

In the above-described embodiment, as described with reference to FIG. 5, it is determined that the scale is attached to the surface of the electric heater 71 when the detected value of the temperature sensor 8 reaches the first specified value. Then, when the detected value of the temperature sensor 8 reaches the second specified value higher than the first specified value, it is determined that the electric heater 71 is overheated. The determination unit 103 determines that the scale is attached to the surface of the electric heater 71 when the rate of increase of the detected value of the temperature sensor 8 is equal to or higher than the third specified value, and the rate of increase of the detected value of the temperature sensor 8 is the third. It may be determined that the electric heater 71 is overheated when it is equal to or higher than the fourth specified value, which is higher than the three specified values. The rate of increase in the detected value of the temperature sensor 8 means the amount of increase in the detected value of the temperature sensor 8 per unit time. When the scale adheres to the surface of the electric heater 71, the scale hinders the heat dissipation of the electric heater 71, so that the temperature of the electric heater 71 rises slowly. On the other hand, when the heat generating region FA of the electric heater 71 comes into a state where it does not come into contact with water, the temperature of the electric heater 71 rises sharply. Therefore, when the determination unit 103 determines that the rate of increase in the detected value of the temperature sensor 8 is equal to or greater than the third specified value and less than the fourth specified value, that is, when the temperature of the electric heater 71 is slowly increasing, electricity is supplied. It can be determined that the scale is attached to the surface of the heater 71. Further, the determination unit 103 determines that the rate of increase of the detected value of the temperature sensor 8 is equal to or higher than the fourth specified value, which is higher than the third specified value, that is, the temperature of the electric heater 71 is rapidly increasing. At that time, it can be determined that the electric heater 71 is overheated.

1 ... Electric boiler, 2 ... Water supply device, 3 ... Lower pipe alignment, 3H ... Internal space, 4 ... Water pipe, 5 ... Rise pipe, 6 ... Upper pipe alignment, 6H ... Internal space, 7 ... Heater device, 8 ... Temperature sensor , 9 ... water level detection device, 10 ... control device, 10A ... arithmetic processing device, 10B ... storage device, 10C ... input / output interface, 11 ... notification device, 12 ... power supply, 21 ... water supply pipe, 22 ... water supply pump, 23 ... Water supply valve, 24 ... drain pipe, 25 ... drain valve, 26 ... steam pipe, 27 ... steam valve, 71 ... electric heater, 72 ... flange, 73 ... connector, 74 ... core material, 75 ... heating wire, 76 ... accommodating member , 77 ... Powder, 78 ... Electrode line, 79 ... Sealing member, 91 ... Detection container, 91H ... Internal space, 92 ... Electrode rod, 92A, 92B, 92C ... Electrode rod, 93 ... Lower communication pipe, 94 ... Upper Communication pipe, 101 ... Temperature data acquisition unit, 102 ... Water level data acquisition unit, 103 ... Judgment unit, 104 ... Water supply control unit, 105 ... Notification control unit, 106 ... Electric heater control unit, 107 ... First specified value storage unit, 108 ... Second specified value storage unit, EG ... Boundary, FA ... Heat generation area, NA ... Non-heat generation area.

Claims (5)

Water pipe and
An electric heater arranged inside the water pipe and
A temperature sensor arranged in a heat generating region on the surface of the electric heater and
A water supply device that supplies water to the water pipe so that the water level of the water pipe is maintained above the heat generation region of the electric heater.
It is provided with an arithmetic processing unit for determining whether or not scale is attached to the surface of the electric heater based on the detected value of the temperature sensor.
The non-heat-generating region of the electric heater is arranged above the heat-generating region.
The temperature sensor is located above the heat generation region.
Electric boiler. The arithmetic processing unit determines whether or not the electric heater is overheated based on the detected value of the temperature sensor.
The electric boiler according to claim 1. The arithmetic processing unit determines that the scale is attached to the surface of the electric heater when the detected value reaches the first specified value, and the second detected value is higher than the first specified value. When the specified value is reached, it is determined that the electric heater is overheated.
The electric boiler according to claim 2. The arithmetic processing unit determines that the scale is attached to the surface of the electric heater when the rate of increase of the detected value is equal to or higher than the third specified value, and the rate of increase of the detected value is the third specified value. It is determined that the electric heater is overheated when it is equal to or higher than the fourth specified value.
The electric boiler according to claim 2. The water pipes are arranged so that the central axis of the water pipe and the vertical axis orthogonal to the horizontal plane are parallel to each other, and a plurality of the water pipes are arranged at intervals in a direction parallel to a predetermined axis in the horizontal plane.
The electric heater is arranged inside each of the plurality of water pipes.
The temperature sensor is at least one placed on one of the electric heater, or is placed in one of the electric heater of the plurality of electrical heaters,
The electric boiler according to any one of claims 1 to 4.

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