JPH03217754A - Hot water supplying apparatus - Google Patents

Abstract

PURPOSE:To prevent the erroneous operation of a malfunction detector in a temperature sensor by detecting the malfunction of the sensor, stopping a heater, stopping the operation of a malfunction detector when a flow sensor detects a first flow rate or less, and releasing the stop of the operation of the malfunction detector which has detected a second flow rate or more. CONSTITUTION:In a hot water supplying apparatus, when a flow sensor 1 detects a flow rate of 3l/min or more, a controller 3 operates a heater 4 based on the supply hot water temperature of a temperature sensor 2 to supply hot water of 60 deg.C through a heat exchanger 5, and when the sensor 1 detects a flow rate of 2.5l/min or less during hot water supply, the controller 3 stops the operation of the heater 4. A malfunction detector 6 for setting the controller 3 to a malfunction stopping state is provided as a temperature sensor short-circuit when the signal of the temperature sensor is 80 deg.C or higher, and as a temperature sensor wire disconnection when it is -5 deg.C or lower. When hot water supply is not performed by inputting the flow rate of the sensor 1, a malfunction detection suppressor 7 for stopping the operation of the detector 6 is provided. The suppressor 7 turns OFF a suppression output when the sensor 1 detects 2.5l/min or more at the time of ON of the suppression output, and turns OFF the suppression output when the sensor 1 detects 2l/min or less by the sensor 1 at the timer of OFF of the suppression output.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an instantaneous water heater that heats hot water by burning gas or oil.

2. Description of the Related Art In a conventional instantaneous water heater, for example, as shown in FIG.
Based on the detected hot water temperature, the control unit 3 operates the heating unit 4 to heat the water in the waterway via the heat exchanger 5, supplying hot water at a constant temperature, for example, 60°C. In addition, an abnormality detection section 6 is provided which causes the control section 3 to be brought into an abnormal stop state when the temperature sensor signal is above 80°C, the temperature sensor is short-circuited, and when it is below -5°C, the temperature sensor is disconnected. ．． With this configuration, even if the temperature sensor is disconnected or short-circuited, the control section 3 controls the heating section 4 with an incorrect temperature sensor signal, so that hot water at a temperature significantly different from the set temperature will not be dispensed.

Problem to be Solved by the Invention However, with the above configuration, when trying to start using the water in a cold region with the water drained to prevent freezing, the control unit 3 may abnormally stop if the temperature is below -5°C. The problem was that it became unusable as is. Furthermore, if we try to lower the temperature at which sensor disconnection is detected in order to solve these problems, the temperature detection range will expand significantly, reducing detection accuracy. There was a problem in that it required adding a circuit, which led to a cost annope. The present invention solves such conventional problems, and aims to prevent malfunction of an abnormality detection circuit of a temperature sensor with a simple configuration.

Means for Solving the Problems In order to solve the above problems, the water heater of the present invention includes a heat exchanger provided in the middle of a waterway, a flow rate sensor that detects the amount of water flowing through the waterway, and a water heater that detects the amount of water flowing through the waterway. a single or plural temperature sensors that detect the temperature of hot water; a heating section that heats the heat exchanger; a control section that controls the heating section based on signals from the flow rate sensor and the temperature sensor; and the temperature sensor. an abnormality detection section that detects an abnormality in the flow rate and performs abnormality processing such as stopping the heating section; and when the flow rate sensor detects a flow rate below a first flow rate, the operation of the abnormality detection section is stopped; The system is equipped with an abnormality detection suppressing section that releases the stoppage of the abnormality detecting section when a flow rate higher than or equal to the flow rate is detected. Effect: With the above-described configuration, the present invention reliably detects an abnormality in the temperature sensor during hot water supply when hot water may be dispensed, and prevents errors caused by the temperature sensor being in an atmosphere below 0°C, that is, in an atmosphere other than water. It is possible to prevent an abnormal stop state due to operation.

EXAMPLE Hereinafter, an example of the present invention will be described based on the accompanying drawings.

FIG. 1 is a functional block diagram of a water heater according to an embodiment of the present invention. Components 1 to 6 are the same as the conventional example, and the flow rate sensor 1
When a flow rate of 31 l/win or more is detected, the control unit 3 activates the heating unit 4 based on the hot water temperature detected by the temperature sensor 2 to heat the water in the water channel via the heat exchanger 5 to a temperature of 60°C. Supplying hot water and measuring 2.5 1 /
When a flow rate of less than sin is detected, the control unit 3 stops the operation of the heating unit 4. Also, when the temperature sensor signal is 80°C or higher, the temperature sensor signal is -5°C.
In the following cases, the temperature sensor is disconnected, and the system is equipped with an abnormality detection section 6 that causes the control section 3 to stop abnormally. Furthermore, in this example, the flow rate of the flow rate sensor is input,
An abnormality detection suppressing section 7 is provided which stops the operation of the abnormality detecting section 6 when hot water is not being supplied.

The abnormality detection unit 7 detects 2.5 at the flow rate sensor l when the suppression output is ON.
4! When detecting /+min or more, the suppression output is turned OFF.
, when the flow rate sensor 1 detects 2 l/win or less when the suppression output is OFF, the suppression output is turned ON. FIG. 2 shows the control unit 3, abnormality detection unit 6, and
7 is a flowchart showing control of the abnormality detection suppressing section 7. FIG. 51 to S5 constitute the abnormality detection suppressing section 7. First, if the suppression flag is ON in S1, the flow rate is changed in S2, and if the flow rate exceeds 2.51 t/lIIin, the suppression flag is turned OFF and the abnormality detection section 6 is activated. If the suppression flag is OFF in St, the suppression flag is reversed to ON when the flow rate is 242/min or less in S4, and the operation of the abnormality detection section 6 is prohibited. 56 to 510 constitute the abnormality detection section 6. First, the abnormality flag is turned off in S6.
, if the suppression flag is OFF in S7, the temperature detected by the temperature sensor is checked in S8 and S9, and if the temperature is below -5''C or above 80°C, which is normally impossible, the abnormality flag is turned ON in 510.

Sll to S15 constitute a control section. Use Sll to check whether the mode is currently driving the heating section 4, and when it is in heating mode, the flow rate is 2.5 1! in S12. ．． /win or less is detected, the heating unit 4 is controlled to stop in S15, and 2.5 is detected in S12.
If it exceeds i/llin, proceed to S13 and directly turn on the heating section 4.
The drive control is performed. Also, if the heating mode is not set in Sll, if a flow rate of 3e/Ilin or more is detected in S14, S
13 controls the drive of the heating section 4, and the flow rate is 3C/Ili.
If it is less than n, the stop control of the heating section 4 is continued.

Therefore, if the temperature sensor is disconnected or overloaded and an uncontrollable temperature is detected and the abnormality flag is turned on, the heating section 4 is controlled to stop at step 315. Further, when the flow rate is low and the heating unit 4 is not driven, the suppression flag is turned on and the abnormality detection unit is not processed.

Furthermore, although FIG. 1 shows an example in which a temperature sensor is provided on the hot water outlet side and feedbank control is applied, the present invention provides a case in which a temperature sensor is provided on the water inlet side and feedforward control is performed based on the flow rate value. It can also be applied when temperature sensors are provided on the hot water outlet side and the water inlet side and feedback and feed forward are used together.

Effects of the Invention As described above, the water heater of the present invention has the effect of preventing the malfunction detection section of the temperature sensor from malfunctioning even when used in a cold region after draining water to prevent freezing.

[Brief explanation of drawings]

FIG. 1 is a functional block diagram of a water heater according to an embodiment of the present invention.
FIG. 2 is a flowchart showing the control details of the embodiment of the present invention, and FIG. 3 is a functional block diagram of a conventional water heater. 1...Flux sensor, 2...Temperature sensor, 3...Control section, 4...Heating section, 5.
... Heat exchanger, 6 ... Abnormality detection section, 7.
...Anomaly detection suppression section.

Claims (2)

[Claims] (1) A heat exchanger provided in the middle of a waterway, a flow rate sensor that detects the amount of water flowing through the waterway, a single or multiple temperature sensors that detect the temperature of water or hot water flowing through the waterway, and the heat exchanger. a heating section that heats the device; a control section that controls the heating section based on signals from the flow rate sensor and the temperature sensor; and a control section that detects an abnormality in the temperature sensor and performs abnormality processing such as stopping the heating section. an abnormality detection section; when the flow rate sensor detects a first flow rate or lower, the operation of the abnormality detection section is stopped; and when the flow rate sensor detects a second flow rate or higher, the operation stoppage of the abnormality detection section is canceled; A water heater equipped with an abnormality detection and suppression section. (2) The control unit starts controlling the heating unit when the flow rate sensor detects a flow rate equal to or higher than the third flow rate, and stops the heating unit when detecting a flow rate equal to or lower than the fourth flow rate, and controls the third flow rate to the third flow rate. 4, the first flow rate is set to be below the fourth flow rate, and the second flow rate is set to be below the third flow rate. water heater.