JP6504516B2 - Hot water storage type electric water heater - Google Patents

Description

  The present invention is an invention relating to a hot water storage type electric water heater provided with a temperature overheat prevention device that shuts off the current supply to the heater when the temperature control means fails.

  As shown in Patent Document 1, the conventional hot water storage type electric water heater is provided with a temperature overheat prevention device composed of a manual reset type bimetal type thermostat, and there is no failure in the temperature control means or no water in the hot water storage tank. Abnormal temperature rise due to heating in Once the overheat protection device has been activated, it is necessary to press the reset switch provided on the overheat protection apparatus to perform a reset operation in order to re-energize. I needed to.

Japanese Patent Application Laid-Open No. 11-132566

  Since the conventional hot water storage type electric water heater is configured as described above, once the manual reset type bimetal operates, it is necessary to request a maintenance contractor to perform reenergization, which is very time-consuming. Therefore, in the normal boiling operation, the overheat protector does not operate, and a predetermined margin is set between the boiling temperature and the operating temperature of the overheat protector so that it operates only during abnormal heating. I have it.

  Sometimes, in addition to the use of pouring hot water into a jar pot, it is sometimes used by pouring hot water directly into cup ramen, coffee, tea, etc. The elevated temperature is required to be high. As a countermeasure, it is conceivable to raise the boiling temperature by the temperature control means and raise the operating temperature of the overheat protection device, but in the case of the storage type electric water heater of the closed structure, when the temperature control means breaks down. It is required by law (the Electrical Appliances and Materials Safety Act) that the temperature of the hot water in the hot water storage tank is below 100 ° C. Therefore, there is a limit to raising the operating temperature of the overheat protection device, and there is a problem that the boiling temperature can not be increased as desired.

  The present invention has been made to solve the above-described problems, and it is possible to increase the boiling temperature of hot water in the hot water storage tank as much as possible, even if the temperature control means fails, in the hot water storage tank. It is an object of the present invention to provide a hot water storage type electric water heater which eliminates the need for requesting a maintenance company to perform reenergization while maintaining the hot water temperature at or below the temperature.

In the water storage type electric water heater of the present invention, a water storage tank for storing hot water, a heater provided below the water storage tank for heating the water in the water storage tank, and a boiling point set for the water in the water storage tank. Temperature control means for controlling energization of the heater for heating to a raised temperature, and turning off the heater when the temperature of the hot water in the hot water storage tank reaches a first temperature higher than the boiling temperature manual reset type to turn off the pressurized heat heater when the first thermal cut-out device is automatic return bimetal, the temperature of hot water in the hot water storage tank reaches a second temperature higher than said first temperature And a second overheat protector that is bimetal , wherein the first overheat protector and the second overheat protector are disposed in proximity to an upper surface of the hot water storage tank. , Said first Overheat protector is characterized in that it is arranged on the upper side of the second overheat protector.

  With such a configuration, since the first overheat protection device is configured by the self-resetting type bimetal type thermostat, in the case of normal boiling operation, although it is not abnormal, boiling is caused for some reason. Since the temperature rise rises and the temperature overheat protector is automatically activated even if it is activated, there is no need to ask the maintenance contractor for a reset operation, and it can be used as it is. Therefore, the margin between the boiling temperature and the operating temperature of the overheat protector can be reduced, and the boiling temperature can be raised.

  In addition, if an abnormal temperature rise occurs due to heating (open air) with no water in the hot water storage tank, even if the first overheat prevention device operates to cut off the current to the heater Since the second overheat protection device also operates due to the temperature rise due to the residual heat, the air-heating is not repeated. In this case, it is necessary to press the reset switch provided on the second overheat protection device to perform the reset operation, and a maintenance contractor is requested.

In addition, since the first overheat protector and the second overheat protector are disposed on the outer surface of the hot water storage tank, the first overheat protector and the second overheat are disposed. The rising prevention device detects the temperature of the part where it is easy to transmit the temperature of the hot and cold water in the hot water storage tank, and the temperature detected by the first overheat protection device and the second overtemperature protection device and inside the hot water storage tank The difference between the temperature and the temperature of the water can be reduced, and since the heat transfer method detects the temperature of the same part, the first overheat protector is more reliable than the second overheat protector. Can be operated quickly.

Furthermore, since the first overheat protection device is disposed on the upper side of the second overheat protection apparatus, the temperature of the hot water is higher toward the top of the hot water storage tank, so the first overheat protection apparatus is Can be operated faster than the second overheat protector.

  Further, in the water storage type electric water heater according to the present invention, the first temperature is equal to or less than 100 degrees.

  With such a configuration, it is possible to maintain the temperature of the hot water in the hot water storage tank at the time of failure of the temperature control means at or below the temperature of 100 ° C.

  According to the present invention, reheating can be performed while maintaining the temperature of the hot water in the hot water storage tank at a temperature equal to or less than 100 ° C., even if the temperature control means fails while increasing the boiling temperature of hot water in the hot water storage tank as much as possible. It is possible to provide a hot water storage type electric water heater which eliminates the need for asking a maintenance contractor.

It is a front view of the hot water storage type electric water heater of this invention. It is an interior view of the hot water storage type electric water heater of this invention. It is a circuit diagram in a hot water storage type electric water heater of an embodiment of the present invention. It is a figure which shows the operating temperature area | region of the overheat prevention device of embodiment of this invention.

Hereinafter, the hot water storage type electric water heater of the present invention will be described with reference to the drawings.
FIG. 1 is a front view of a hot water storage type electric water heater of the present invention.

  As shown in FIG. 1, the hot water storage type electric water heater 1 is installed on the wall surface above the sink 7, and the hot water outlet piping (not shown) to the faucet 2 and the drainage pipe 3 similarly installed on the wall surface. It is connected by drainage piping (not shown).

  In addition, the hot water storage type electric water heater 1 is connected with a water stop valve (not shown) and a water supply pipe (not shown), and connected with a power outlet 6 and a power cord 5. A water supply pipe (not shown) is also connected to the faucet 2 from a water stop valve (not shown).

  Furthermore, the storage water type electric water heater 1 is provided with a control panel 4 provided with a heating switch, a temperature setting switch and the like (not shown).

  Water is supplied to a hot water storage tank (not shown) in the hot water storage type electric water heater 1 through a water supply pipe (not shown) from a water stop valve (not shown).

  And, by turning on the heating switch (not shown) provided on the operation panel 4 provided in the hot water storage type electric water heater 1, the hot water of the hot water storage tank (not shown) in the hot water storage type electric water heater 1 is A heater (not shown) is controlled by a temperature control means (not shown) and is heated to a predetermined heating set temperature T1.

  Hot and cold water heated to a predetermined temperature is discharged from the faucet 2 through a hot water outlet pipe (not shown).

  Further, the expanded water generated at the time of boiling is discharged from the drainage pipe 3 via a drainage pipe (not shown).

  FIG. 2 is an interior view of the hot water storage type electric water heater of the present invention. This FIG. 2 has shown the state which removed the front cover of the hot water storage type electric water heater 1 of FIG. 1, and exposed the inside.

  A hot water storage tank 8 is provided inside the hot water storage type electric water heater 1. Moreover, the control panel 4 in which the boiling switch 9 and a temperature setting switch etc. (not shown) were provided is also provided.

  In addition, a heater 10 for heating the hot and cold water in the hot water storage tank 8 is provided below the hot water storage tank 8, and a temperature detection unit 11 composed of a thermistor is attached to the outer surface of the hot water storage tank 8. In order to boil the hot and cold water in the hot water storage tank 8 to the heating setting temperature T1 previously set by the temperature setting switch (not shown) of the operation panel 4 based on the stored temperature, the heater 10 is energized. Control.

  Furthermore, when the temperature control means composed of the temperature detection means 11 and the temperature control unit 15 fails on the outer surface above the hot water storage tank 8 and the outer surface of the hot water storage tank 8 rises above the heating set temperature T1. A first overheat protection device 13 and a second overheat protection device 14 are provided in close proximity to each other to cut off the current supply to the heater 10.

  Here, the first overheat protector 13 is constituted by an automatic return bimetal thermostat, and the second overheat protector 14 is constituted by a manual return bimetal thermostat. The riser 13 is located above the second overtemperature protector 14. The operating temperature T2 of the first overheat protection device 13 is set to be lower than the operating temperature T3 of the second overheat protection device 14.

  Furthermore, as a countermeasure in case both of the two overheat protection devices fail, a thermal fuse 12 for interrupting the energization of the heater 10 is also provided on the outer surface above the hot water storage tank 8. The operating temperature T4 of the thermal fuse 12 is set higher than the operating temperature T3 of the second overheat protection device 14.

In the present embodiment, the first overheat protector 13 is located above the second overheat protector 14. However, as a reference example , the first overheat protector 13 is adjusted by adjusting the operating temperatures T2 and T3. The positional relationship may be upside down or the same height as long as the overheat protection device of the present invention can be operated reliably earlier than the second overheat protection device. Also, they need not be in close positional relationship, and furthermore, both of the first overheat protection device 13 and the second overheat protection device 14 or one of them may be the surface of the flange of the heater 10 You may provide in the part.

  FIG. 3 is a circuit diagram of a hot water storage type electric water heater according to an embodiment of the present invention.

  The power supply 16 supplied from the power supply outlet through the power supply cord comprises a heating switch 9, a heating heater 10, a temperature control unit 15, a temperature fuse 12, and a thermostat of an automatic reset type bimetal type. A first overheat protection device 13 and a second overheat protection device 14 configured of a manual reset bimetal thermostat are connected in series.

  The temperature control unit 15 opens and closes the contacts of the relay, and semiconductors such as triacs based on the heating set temperature T1 set by the temperature setting switch (not shown) of the control panel 4 and the temperature detected by the temperature detecting means 11. The energization of the heater 10 is controlled by driving the element.

  This first overheat protection device 13 uses a bimetal that operates to shut off the current supply to the heating heater when the outer surface of the hot water storage tank exceeds a predetermined temperature T2 higher than the heating setting temperature T1. It is an automatic reset type thermostat. Further, the second overheat protection device 14 operates when the outer surface of the hot water storage tank exceeds a predetermined temperature T3 higher than the operation temperature T2 of the first overheat protection device 13 and the heating heater It is a manual reset type thermostat using a bimetal that shuts off the power supply.

  The operating temperature T4 of the thermal fuse 12 is set higher than the operating temperature T3 of the second overheat protection device 14.

  In the normal state, the temperature fuse 12 is in the on state, the contacts of the first overheat protection device 13 and the second overheat protection device 14 are closed, and the heating switch 9 is turned on. The control unit 15 controls the power supply to the heater 10, and the hot and cold water in the hot water storage tank is boiled to the heating set temperature T1.

  Then, in the normal boiling operation, if the boiling temperature rises to T2 or more for some reason although it is not abnormal, the first overheat protection device 13 operates to open its contact point, and the heating heater Cut off the power to 10. Thereafter, when the temperature of the hot and cold water in the hot water storage tank is lowered, the contact is automatically closed and the energization of the heater 10 is resumed.

  In addition, when an abnormal temperature rise occurs due to heating (airing) in a state where there is no water in the hot water storage tank, the first overheat protection device 13 operates to cut off the energization to the heater. Also, since the second overheat protection device 14 is also activated by the temperature rise due to the residual heat, the air-heating is not repeated. In this case, it is necessary to press the reset switch provided in the second overheat protection device 14 to perform the reset operation, and a maintenance contractor is requested.

  When the temperature detection means 11 or the temperature control unit 15 breaks down, the first overheat prevention device 13 operates to cut off the energization to the heater 10, but the temperature of the hot water in the hot water storage tank Decreases, the energization of the heater 10 will be resumed. Therefore, in this case, the second temperature overheat prevention device 14 does not operate, and the boiling temperature is controlled to T2 by the first temperature overheat prevention device 13. It is desirable to include failure detection means for the temperature detection means 11 and the temperature control unit 15.

  Furthermore, when all of the temperature control unit 15, the first overheat protection device 13, and the second overheat protection device 14 fail, the temperature fuse 12 is melted and the heating heater 10 is energized. Cut off.

  FIG. 4 is a diagram showing an operating temperature range of the overheat protection device according to the embodiment of the present invention.

  A is a boiling temperature range (variation in boiling maximum temperature) by the temperature control unit 15, and B is an operating temperature range of the first overheat prevention device 13 (variation in temperature at which a bimetal contact opens) And C is the operating temperature range of the second overheat protection device 14 (the variation of the temperature at which the bimetal contact opens).

  For example, the boiling temperature (heating set temperature) T1 by the temperature control unit 15 is 90 ° C., the operating temperature T2 of the first overheat protection device 13 is 95 ° C., and the operating temperature T3 of the second overheat protection device 14 Is set at 100.degree. C., but there is a width (variation) in the operation area (temperature at which the contact opens) depending on the usage condition of the hot water and the accuracy of parts.

  Further, since the temperature detection means 11, the first overheat protection device 13, and the second overheat protection device 14 detect the surface temperature of the hot water storage tank 8, the actual temperature of the hot water in the hot water storage tank 8 Is slightly higher than the detected temperature.

  Therefore, the operating temperature T2 of the first overheat protection device 13 is the difference between the temperature at which the bimetal contact opens and the difference between the surface temperature of the hot water storage tank and the actual hot water temperature in the hot water storage tank, and further to the heater. The temperature of the hot and cold water in the hot water storage tank is determined so as not to exceed 100 ° C. in consideration of the temperature rise due to the residual heat after the current supply is cut off.

DESCRIPTION OF SYMBOLS 1 ... Storage water type electric water heater 2 ... Water faucet 3 ... Drain pipe 4 ... Control panel 5 ... Power supply cord 6 ... Power outlet 7 ... Sink 8 ... Storage water tank 9 ... Boiling switch 10 ... Heating heater 11 ... Temperature detection means (Sir Mr.)
12: Thermal fuse 13: First overheat protector (automatic return type bimetal)
14 2nd overheat protection device (manual reset type bimetal)
15: Temperature control unit 16: Power supply A: Boiling temperature range by temperature control unit B: Operating temperature range of the first overheat prevention device C: Operating temperature range of the second overheat prevention device

Claims (2)

With a hot water storage tank for storing hot and cold water,
A heater provided below the hot water storage tank for heating hot and cold water in the hot water storage tank ;
Temperature control means for controlling energization of the heater to heat the hot and cold water in the hot water storage tank to a set boiling temperature;
A first overheat protection device that is an automatic return bimetal that turns off the heater when the temperature of the hot water in the hot water storage tank reaches a first temperature higher than the boiling temperature;
And a second overheat protection device which is a manual reset type bimetal that turns off the heating heater when the temperature of the hot water in the hot water storage tank reaches a second temperature higher than the first temperature;
The first overheat protector and the second overheat protector are disposed in close proximity above the outer surface of the hot water storage tank,
The hot water storage type electric water heater, wherein the first overheat protection device is disposed on the upper side of the second overheat protection apparatus. The hot water storage type electric water heater according to claim 1, wherein the first temperature is equal to or less than one hundred degrees centigrade.

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