JPH0914751A - Hot water heater - Google Patents

Abstract

PURPOSE: To improve safety and ease of handling by shortening a specified time length as the temperature of delivery hot water goes up to a high temperature according to a relationship between the temperature and time in the possibility of causing scalding. CONSTITUTION: Receiving a detection signal from a temperature sensor 15, a burner controller 16 adjusts a proportional control valve 11 so that the temperature of delivery hot water reaches a value set by a remote control 17 to make the temperature of delivery hot water coincide with a set temperature. As long as the set temperature is below a specified value (e.g. 50 deg.C or lower), the temperature of delivery hot water is determined to exceed the set temperature, when the temperature of delivery hot water continues to rise above the set temperature beyond the specified value for a specified time length and a processing for alarming, stopping combustion or the like is performed. Thus, the specified time for judging abnormality in operation is limited to an arbitrary range of the set temperature and is shortened as it goes up to a high temperature according to a relationship between the temperature and time in the possibility of causing scalding. This accomplishes a safe application and prevents impaired ease of handling because no abnormality is found to judge outside the arbitrary range of the set temperature.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot water supply apparatus having a safety function of comparing a set temperature with a hot water discharge temperature under a predetermined condition to detect an abnormality and perform processing such as combustion stop.

[0002]

2. Description of the Related Art A conventional safety function of the above hot water supply apparatus is shown in the flowchart of FIG. It is determined whether or not the temperature of the hot water supplied by the hot water temperature control in S4 is higher than the set temperature by a predetermined temperature or more in S5.
Then, it is judged whether or not the state continues for a predetermined time or longer, and the combustion is stopped when the predetermined time elapses. On the other hand, FIG. 3 is a graph showing "relationship between time and temperature for skin burns" in "Household Gas Appliance Performance Standards" created by the Product Technology Development Department of Osaka Gas Co., Ltd., where the vertical axis indicates the skin surface temperature ( C), the horizontal axis represents the elapsed time (s), the area above the solid line b is the area where the skin is damaged, the area below the broken line a is the safe area, and the area between the broken line a and the solid line b is the original It is an area where you can return to the state of. According to this, for example, 5
2 minutes at 0 ° C, less than 10 seconds at 55 ° C, about 2. at 60 ° C.
You can see that it burns after 5 seconds. Like this, the possibility of being burned changes depending on the relationship between temperature and time, and the higher the temperature, the shorter the time.
You can understand that it appears (hereinafter called a burn curve).

[0003]

However, in the above-mentioned conventional safety function, since the predetermined time for judging an abnormality is constant regardless of the set temperature, for example, the user is aware of the set temperature. If the hot water temperature is 50 ° C or less and the hot water temperature is 60 ° C, you may get burned in a short time as described above, so it may not be in time even if an abnormal judgment is made and combustion is stopped. is there. Moreover, although the temperature is lower than the temperature for judging abnormalities, the abnormality is not detected, but there is a risk of burns due to the corresponding temperature and time on the burn curve.
There is a safety problem. On the other hand, in the hot water supply device, the hot water discharge temperature may be considerably higher than the set temperature when the incoming water temperature is relatively high and the flow rate is small (for example, in the device employing the solar system, the incoming water temperature is 40 ° C and the incoming water amount is 3
~ 4 liters, set temperature 60 ℃, hot water temperature is 8
It may be 0 ° C or higher). However, in this case, since the user recognizes that the set temperature is high, it is unlikely that the user will touch the hot water and cause a burn, and conversely, in this case, processing such as combustion stop is performed after a predetermined time elapses. Then, the usability becomes worse.

[0004]

SUMMARY OF THE INVENTION Therefore, the present invention focuses on the relationship between temperature and time based on the above-mentioned burn curve, and provides a safer hot water supply apparatus which does not impair usability. A temperature setting means for setting the temperature of the hot water to be discharged, a temperature detecting means for detecting the temperature of the hot water to be discharged, a set temperature set by the temperature setting means and a hot water temperature detected by the temperature detecting means. In a hot water supply device provided with a determination means for comparing the above conditions with a predetermined condition to determine an abnormal operation, the condition is set to a predetermined value in a range of an arbitrary set temperature, in which the hot water discharge temperature is higher than the set temperature by a predetermined temperature or more. It is considered to be abnormal when it continues for more than a time, and the predetermined time is shortened as the hot water temperature rises in accordance with the relationship between the temperature and the time that may cause burns. Is shall. Further, it is desirable that the upper limit of the arbitrary set temperature range is 50 ° C.

[0005]

[Operation] If the hot water temperature continues to be higher than the set temperature by a predetermined temperature or more within a range of an arbitrary set temperature such as a temperature below which the user is consciously trying to touch the hot water, the hot water temperature causes burns. Abnormality judgment is made before the elapse of the wake-up time and combustion is stopped. This time becomes shorter as the temperature becomes higher. On the contrary, even if the hot water outlet temperature rises outside the above-mentioned arbitrary set temperature range, an abnormality judgment is not made in the relation between the burn, the temperature and the time, so the usability is not impaired. Also, the upper limit of the above-mentioned arbitrary set temperature range is 5
0 ° C. is considered to be the optimum value as the upper limit of the temperature at which the user can consciously touch the hot water.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic view of a water heater to which the present invention is applied. A gas burner 3 and a heat exchanger 4 are provided in a combustion chamber 2 in a housing 1, and a water pipe passing through the heat exchanger 4 is provided. 5, a water supply pipe 6 connected to the water supply is connected to the upstream side, and a tap water pipe 8 provided with a faucet 7 such as a bathroom or a washroom is connected to the downstream side. The gas burner 3 is equipped with an ignition device (not shown), and a gas supply pipe 9 is connected to the gas burner 3. The main valve 10, the proportional control valve 11, and the main valve 12 are arranged in this order from the upstream side. Two solenoid valves are provided. The water supply pipe 6 is provided with a water amount sensor 13 for detecting the amount of water, a temperature sensor 14 for detecting the incoming water temperature, and the hot water outlet pipe 8 is provided with a temperature sensor 15 for detecting the hot water outlet temperature. It is connected to the controller 16 to input the presence / absence of water flow, the incoming water temperature, and the outgoing hot water temperature, respectively. Furthermore, the burner controller 16
Remote control 1 with a temperature setting knob to set the hot water temperature
The operation information of No. 7 can be received, and the opening / closing operation of the main valve 10 and the main valve 12 and the adjustment operation of the proportional control valve 11 are performed based on the information. Therefore, in the water heater thus configured, when water passes through the water supply pipe 6 by opening the faucet 7 attached to the hot water outlet pipe 8, the water amount sensor 13 detects the passage of the water and the burner controller A signal is sent to the burner controller 16, and a combustion command signal is output from the burner controller 16 which receives the water passage signal, which opens the main valve 10 and the main valve 12 and ignites the gas burner 3.

The burner controller 16 includes:
While receiving the detection signal from the temperature sensor 15, the proportional control valve 11 is adjusted so that the hot water temperature set by the remote controller 17 is adjusted, and the temperature adjusting function for matching the hot water temperature with the set temperature is set. Below a predetermined value (eg 50
Only in the case of (° C or lower), when the hot water temperature exceeds the set temperature by a predetermined value or more for a predetermined time, it is judged as an abnormality and a safety function is provided to perform processing such as alarm and combustion stop. However, here, in particular, the predetermined time until it is determined to be abnormal is variable according to the hot water temperature. The change of the predetermined time is given by the relationship between the temperature and time corresponding to the burn curve shown above. The safety function will be described below with reference to the flowchart of FIG. First, in step 1 (hereinafter simply referred to as S1), it is determined whether or not the flow rate detected by the water amount sensor 13 by opening the faucet 7 is equal to or higher than a predetermined flow rate, and YES.
In the case of S1, the burner controller 16 performs ignition control in S2, and when ignition is confirmed in S3, the proportional control valve 11 is operated in S4.
The hot water temperature control is performed so that the hot water is discharged at the temperature set by the remote controller 17 by the adjustment operation. Next, in S5, it is determined whether or not the set temperature set by the remote controller 17 is 50 ° C. or lower. If YES, the tap water temperature t _o is 5 in S6.
Check if between 5 ° C and 58 ° C. Within this range, the shorter time in the safe area derived according to the burn curve a in FIG. 3, that is, the time corresponding to 58 ° C., which is 5 seconds, is judged in S7 and when 5 seconds have elapsed When it is determined that the combustion is abnormal, the solenoid valve such as the main valve is closed, the gas supply is shut off, and the combustion is immediately stopped. Also if the check is NO in S6, followed by S8, checking whether the hot water temperature t _o is between 60 ° C. from the higher 58 ° C. than S6. In this temperature range, the burn curve a has a lapse time of less than 2 seconds at 60 ° C., so the judgment time is slightly earlier than 2 seconds.
Set to seconds. Therefore, if it is confirmed that 2 seconds have passed in S9, the combustion is immediately stopped. And, if the check is NO at S8, in S10, the hot water temperature t _o 6
Whether or not the temperature is 0 ° C. or higher is checked. However, since the burn curve a has an elapsed time of 1 second at 65 ° C., the determination time is set to 1 second here and 1 is set in S11.
The combustion is stopped immediately after confirming the elapse of seconds.

As described above, in the above embodiment, when the set temperature is instructed by the user at a temperature of 50 ° C. or less, which is the temperature at which the user consciously touches the hot water, the actual hot water temperature and the burn curve are associated with each other. By changing the time to judge the abnormality and stopping the combustion before a burn occurs, the safety is further enhanced. On the contrary, if the temperature is outside the set temperature range for operating the above-mentioned safety function, for example, when the set temperature is 60 ° C. and the hot water temperature is 80 ° C., no abnormality judgment is made. Therefore, hot water supply is continued, or the set temperature is low and the hot water temperature is high. In this case, the predetermined time for determining the abnormality becomes long, and therefore the usability does not deteriorate in any case. In the above embodiment, 5
Although the judgment time was changed in each of the three ranges of 5 to 58 ° C., 58 to 60 ° C., and 60 ° C. or higher, the temperature range to be checked can be further divided into smaller ranges, or conversely wider. The upper limit of the set temperature to which the safety function is applied is considered to be the temperature at which the user can consciously touch the hot water.
Although 0 ° C. is given as the optimum value, this value may be appropriately changed, and the lower limit can be set. Further, in the above description, the solar system is taken into consideration in the example in which the abnormality determination is not performed outside the set temperature range, but depending on the type of the hot water supply device, at the set temperature outside the set range, the hot water outlet temperature is set to be higher than the set temperature. A conventional safety function for determining an abnormality may be added when the temperature is higher than the temperature and continues for a certain period of time. Further, although the above description has been made with respect to the example used for the water heater, it is needless to say that it can be applied to other water heaters such as a bath device with a water heater.

[0009]

As described above, according to the present invention, the predetermined time for judging an abnormal operation is limited to a range of an arbitrary set temperature, and the hot water outlet temperature becomes high according to the relationship between the temperature and the time at which there is a possibility of burn. By making the length shorter, it is possible to judge abnormalities before a burn occurs in the temperature range where the user tries to touch the hot water, and it is possible to use safely. On the contrary, even if the hot water temperature rises outside the arbitrary set temperature range,
Since no abnormality judgment is made regarding the relationship between burns, temperature, and time, hot water supply continues and usability is not impaired. Further, the upper limit of 50 ° C. of the arbitrary set temperature range is considered to be the optimum value as the upper limit of the temperature at which the user can consciously touch the hot water.

[Brief description of the drawings]

FIG. 1 is a schematic view of a water heater.

FIG. 2 is a flowchart of a safety function.

FIG. 3 is a graph showing the relationship between time and temperature for skin burns.

FIG. 4 is a flowchart of a conventional safety function.

[Explanation of symbols] 1 ・ ・ Housing, 2 ・ ・ Combustion chamber, 3 ・ ・ Gas burner,
4 ・ ・ Heat exchanger, 5 ・ ・ Water pipe, 6 ・ ・ Water pipe, 8 ・ ・
Hot water supply pipe, 9 ... Gas supply pipe, 10 ... Main valve, 11 ... Proportional control valve, 13 ... Water amount sensor, 14, 15 ... Temperature sensor, 16 ... Burner controller.

Claims (2)

[Claims] 1. A temperature setting means for setting a temperature of hot water to be discharged, a temperature detecting means for detecting a temperature of hot water to be discharged, and a set temperature set by the temperature setting means and a temperature detecting means. In the hot water supply device, the hot water supply device is provided with a determination means for determining an abnormal operation by comparing the hot water discharge temperature with a predetermined temperature, and the hot water discharge temperature is a predetermined temperature or more higher than a predetermined temperature in an arbitrary set temperature range. It is considered as abnormal when it continues for a predetermined time or more in a high state, and the predetermined time is shortened as the hot water temperature rises according to the relationship between the temperature and the time at which burns may occur. Hot water supply device characterized in that. 2. The upper limit of the range of the arbitrary set temperature is 50.
The hot water supply apparatus according to claim 1, wherein the temperature is set to ° C.