JPH0128855B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention attempts to control the opening and closing of combustion by calculating the minimum ignition water amount of an instantaneous water heater from the water temperature and heating capacity.

Conventional configuration and its problems Conventionally, the minimum amount of water to ignite in a water heater is determined by the relationship between the heating device's capacity and the maximum incoming water temperature, and is set to provide a temperature that does not normally boil. For example, assuming the maximum inlet water temperature in summer is 30℃, the maximum hot water temperature is kept below 95℃. An example of a conventional example of these ignition water amount setting means is shown in FIG. Water enters the hydraulic response device 2 from the inflow channel 1,
It is supplied to the outside from a hot water outlet pipe 10 via a heat exchanger 9. At this time, the water passes through the ventilate section 6, and a high pressure chamber 3 and a low pressure chamber 4 are created in front and behind the diaphragm 5 due to the ventilic effect. This pressure difference is used to send a mechanical or electrical signal to the heating controller 12 using the hydraulic response rod 8, which causes the heating device 13 to start combustion. It is a known technology that this is called the minimum ignition water amount and is determined by the settings of the components of the hydraulic response device 2 and the connection means with the heating controller. When the amount of ignition water falls below the minimum ignition water amount, the pressure difference between the high pressure chamber 3 and the low pressure chamber 4 becomes small and is pushed back by the spring 7, the signal to the heating controller 12 is stopped, and combustion is stopped.

In the conventional example, as described above, the minimum ignition water amount is determined by the components of the hydraulic response device 2 and the heating controller 12.
The problem is that the minimum amount of ignition water varies depending on the processing accuracy of the component parts. In addition, as mentioned at the beginning, the minimum ignition water amount is set assuming the maximum water inlet temperature in summer, so it is necessarily set high. Pressure from the water side is applied to the hot water side, which may reduce the amount of hot water, and this tendency is especially strong when using a shower.
Another drawback was that sometimes the amount of ignition water would drop below the minimum ignition water level, causing the water heater to stop burning and only water to be supplied.

Purpose of the Invention The present invention aims to eliminate such drawbacks, and one is to detect the actual incoming water temperature rather than the assumed incoming water temperature, thereby setting the minimum ignition water amount according to the water temperature to provide comfortable hot water. is to supply
The other purpose is to reduce variations in the minimum ignition water amount due to variations in component parts.

Structure of the Invention For the above purpose, the present invention detects the water temperature, calculates the required minimum amount of ignition water from the heating capacity, and controls the start and stop of combustion.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention is shown in FIGS. 2 and 3 below.

Water enters the flow rate detection device 14 from the inflow path 1, passes through the heat exchanger 9, and is supplied to the outside from the outlet pipe 10. As an example of the configuration of the flow rate detection device 14, a permanent magnetic body 14b installed on a blade wheel 14a is rotated by the flow of water, so that a magnetoresistive element 14c is generated.
It is already known that the rotation speed can be detected as a pulse signal by capturing magnetic changes, and the rotation speed has a linear characteristic with respect to the flow rate.
Therefore, the flow rate can be determined by measuring the number of pulses of the pulse signal.

Next, the operation will be explained according to the control block diagram shown in FIG. Based on the signal sent from the inlet water temperature detector 15 and the signal from the heating capacity storage section 17, the ignition water amount calculation section 18 calculates the minimum ignition water amount, and the signal sent from the flow rate detection device 14 is calculated. If the temperature is high, a signal to start combustion is sent from the heating device drive section 19 to the heating controller 12, and the heating device 1
3, the heat exchanger 9 is heated and hot water is tapped.
In addition, when the heating controller 12 changes the capacity to multiple levels, the change signal is transmitted to the heating capacity storage unit 17 and the calculation is performed again using the signal from the heating capacity storage unit 17 and the signal from the inlet water temperature detector 15. It is something to do.
Furthermore, the capacity storage section 17 is replaceable, and even when water heaters with different heating capacities are manufactured, the control section 16 can be shared by simply replacing the capacity storage section 17.

Effects of the Invention As described above, the present invention calculates the minimum ignition water amount from the water temperature and heating capacity, and can accurately detect the water amount, so it can be lowered without boiling than before. This allows for a stable supply of hot water. Furthermore, since the amount of water can be determined quantitatively, it is possible to reduce the large variations in the minimum ignition water amount that occur in conventional hydraulic response devices due to variations in component parts. Furthermore, by making the capacity storage unit convertible, the control unit can be shared even if the heating capacity is different.

Furthermore, by changing the amount of ignition water according to the water temperature, high-temperature hot water can be obtained even when the amount of water entering is small, without being affected by the temperature of entering water.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a conventional water heater, FIG. 2 is a block diagram of a water heater according to an embodiment of the present invention, and FIG. 3 is a control block diagram showing the operation of the water heater. 2...Hydraulic response device, 9...Heat exchanger, 11...
... Gas introduction path, 12 ... Heating controller, 13 ... Heating device, 14 ... Flow rate detection device, 15 ... Incoming water temperature detector, 16 ... Control section, 17 ... Heating capacity storage section, 18 ... Ignition water amount calculation section, 19... Heating device drive section.

Claims (1)

[Claims] 1. A heat exchanger that heats water, a heating device that heats this heat exchanger, a flow rate detection device that detects the amount of water flowing into the heat exchanger, a heating controller that controls the heating device, and the heat exchanger. An inlet water temperature detector provided on the inlet side of the vessel, and a control unit that operates the heating controller based on signals from the inlet water temperature detector and the flow rate detection device, and the control unit controls the heating capacity of the heating device. a storage section, an ignition water amount calculation section that calculates a minimum ignition water amount from the signal from the heating capacity storage section and the signal from the water input temperature detector, and an ignition water amount calculation section that calculates the minimum ignition water amount from the signal from the ignition water amount calculation section; A water heater comprising a heating device drive unit that sends a signal to start combustion to the heating controller when the signal is high.