JPH05118654A - Controlling method for water control valve - Google Patents

Abstract

PURPOSE:To eliminate from the use of a hot-water supplying apparatus the possibility of excessive opening or excessive narrowing of the control valve for the control of the flow rate of water so that the flow rate can be set in a stabilized state at an early point of time and hence the temperature of the hot water can be stabilized from an early stage. CONSTITUTION:There are provided a heat exchanger 1; a burner 2 at which the degree of the combustion is variable; a feedwater thermistor 4 on the inlet side of the heat exchanger 1; a sensor 5 for determining the flow rate of water; a valve 6 for controlling the flow rate of water; a thermistor 3 for the hot water supplied provided on the outlet side of the heat exchanger 1; a temperature-setting part 7 by which to set a desirable temperature; a calculating part 10 for calculating the required calorific value from the feedwater temperature, set temperature, and flow rate of water; a first control part 11 for deciding correction values for individual temperatures of hot water; a second control part 12 for controlling a fuel supply part; and a third control part 13 for controlling the valve for controlling the flow rate of water.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling a water quantity control valve of a water heater.

[0002]

2. Description of the Related Art As a conventional example technically closest to the present invention, for example, when a tap is opened and hot water is started, a water amount sensor detects a water flow, a burner starts combustion, and after ignition, a water temperature is set. Calculate the required amount of heat by multiplying the difference in temperature by the amount of water, continue combustion at the corresponding amount of combustion, feedback control the amount of combustion to reach the set temperature, and make sure that as much water as possible flows within the allowable range of the set temperature. ,
Some adjusted the water control valve.

[0003]

However, in such a conventional example, as shown in FIG. 3, the sampling period of the data in the water amount sensor for detecting the water amount and the timing of moving the water amount control valve are independent. Therefore, the amount of water is measured during operation of the water amount control valve, or the water amount control valve is moved while the amount of water is changing, which causes an offset state that is larger or smaller than the target value for flow control. Then, there is a problem that it takes time for the water amount to stabilize, or the water temperature control valve opens too much and the water temperature undershoots or overshoots due to excessive throttling.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and the above-mentioned problems are solved by alternately performing water amount detection and water amount control valve opening / closing control. It aims to solve problems.

[0005]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an embodiment of the present invention.
First, the structure of the water heater will be described. A burner 2 that burns fuel and a heat exchanger 1 that heats water by the burner 2.
A water supply thermistor 4 for detecting the water supply temperature on the water supply side to the heat exchanger 1, a hot water supply thermistor 3 for detecting the hot water temperature on the hot water discharge side from the heat exchanger 1, and the heat exchanger 1. A water amount sensor 5 for detecting the amount of water supplied on the water supply side of 1, a water amount control valve 6 for controlling the water amount on the water supply side of the heat exchanger 1, and a temperature setting for setting a desired hot water temperature. A unit 7, a calculation unit 10 for calculating a required heat amount by multiplying a difference between the water supply temperature detected from the water supply thermistor 4 and a set temperature by a water amount, and means for determining a correction value based on the temperature detected by the hot water thermistor 3. The 1st control part 11 which has, the fuel supply part 8 which can change a combustion amount, the 2nd control part 12 which controls the said fuel supply part 8, and the 3rd control part which controls the water quantity control valve 6 are included. Have 13.

[0006]

[Operation] Next, the operation will be described. When the tap 14 is opened and tapping is started, the water amount sensor 5 generates a pulse in a cycle inversely proportional to the water amount. This pulse is taken into the calculation unit 10 to calculate the amount of water. Here, the feed water temperature is T ₁ , the set temperature is T,
Hot water temperature is T ₂ , water amount is Q, combustion amount (heat supply) is S,
When the efficiency of the heat exchanger is η, the opening of the water flow control valve 6 is adjusted so that Q = S × η / (T-T ₁ ).

Further, even if the opening of the water quantity control valve 6 is adjusted so as to increase the water quantity Q, if the maximum flow rate is limited by the faucet 14, the tap water temperature T ₂ rises. In this case, the fuel supply unit 8 is corrected by the control of the first control unit 11 and the second control unit 12 so as to reduce the combustion amount S. In this way, the control is performed so that the temperature becomes as close as possible to the set temperature T and the water amount Q flows as much as possible. In the present invention, particularly regarding the water amount control, the water amount is calculated as shown in FIG. The feature is that the control is unified such as driving, calculating the water amount, and driving the water amount control valve.

[0008]

As described above, according to the present invention, the control is performed by calculating the water flow rate and then driving the water amount control valve.
The water flow rate control valve is driven after calculating the water flow rate, and this process is repeated, so that the water flow rate control valve does not open too much and is not throttled too much, a stable flow rate can be set quickly, and the temperature of the hot water can be stabilized quickly. The effect is obtained.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 is a time chart diagram of a water amount control system of the present invention.

FIG. 3 is a time chart of a conventional water amount control system.

[Explanation of symbols]

 1 Heat Exchanger 2 Burner 3 Hot Water Thermistor 4 Water Supply Thermistor 5 Water Volume Sensor 6 Water Volume Control Valve 7 Temperature Setting Section 8 Fuel Supply Section 9 Control Board 10 Computing Section 11 First Control Section 12 Second Control Section 13 Third Control Part 14 Faucet

Claims (1)

[Claims] 1. A heat exchanger, a burner having a variable combustion amount,
Water supply thermistor provided on the inlet side of the heat exchanger, water amount sensor, water amount control valve, hot water thermistor provided on the outlet side of the heat exchanger, temperature setting unit for setting the desired temperature, water supply temperature and set temperature And a calculation unit that calculates the required amount of heat from the amount of water and a first control unit that determines a correction value based on the hot water temperature.
In the control of the water heater having the second control unit for controlling the fuel supply unit and the third control unit for controlling the water amount control valve, the calculation of the water amount and the driving of the water amount control valve are alternately repeated. However, the method of controlling the water volume control valve is characterized by adjusting to the proper water volume.