JPH053842U - Water heater - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] To provide a water heater with improved so-called hot water discharge characteristics at the time of rising immediately after ignition and for rapidly changing the amount of hot water discharged from a stable hot water discharge state. [Structure] A burner 2 for burning fuel, a heat exchanger 1 for heating water by the burner 2, a water supply thermistor 4 and a flow rate sensor 5 on the water supply side of the heat exchanger 1, a hot water thermistor 3 on the hot water side, and A calculation unit 8 that calculates the necessary capacity by multiplying the difference between the supply water temperature and the set temperature by the flow rate, a first control unit 9 that determines a correction value based on the hot water temperature, and a fuel supply unit 6 that makes the combustion amount variable. , And a second control unit 10 that controls the fuel supply unit 6.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to improvement of transient response of feedforward control of a water heater.

[0002]

[Prior Art]

 In the conventional feedforward control, the flow rate was multiplied by the difference between the set temperature and the feed water temperature to calculate the capacity, and the combustion amount was controlled according to the required capacity.

[0003]

[Problems to be solved by the device]

 However, in such a conventional feedforward method, the stable state is the base, and the input data is basically in the stable period.Therefore, at the start-up immediately after ignition and in the stable hot water discharge state. Therefore, there was a problem that the response was so poor during the transitional period that the amount of tap water was suddenly changed.

[0004]

[Means for Solving the Problems]

 The present invention has been made by paying attention to such a conventional problem, and solves the above-mentioned problem by performing correction in accordance with the outlet heated water temperature in the feedforward control in the transition period. It is an object.

[0005]

【Example】

 An embodiment 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 configuration of the water heater will be described. A burner 2 that burns fuel, a heat exchanger 1 that heats water by the burner 2, and a water supply side to the heat exchanger 1 detect the water supply temperature. A water supply thermistor 4, a hot water discharge thermistor 3 for detecting the temperature of hot water discharged from the heat exchanger 1, a flow rate sensor 5 for detecting the amount of water supplied on the water supply side of the heat exchanger 1, A first control having a calculator 8 that calculates a required capacity by multiplying a difference between the water supply temperature detected from the water supply thermistor 4 and a set temperature by a flow rate, and a unit that determines a correction value based on the temperature detected by the hot water thermistor 3. It has a unit 9, a fuel supply unit 6 that can change the amount of combustion, and a second control unit 10 that controls the fuel supply unit 6.

[0006]

[Action]

 Next, the operation will be described. Conventionally, when the tap 11 is opened and tapping is started, the burner 2 starts combustion, and after ignition, the difference between the feed water temperature and the set temperature is multiplied by the flow rate to calculate the required capacity, and combustion is continued at the corresponding combustion amount. It was a method. However, immediately after ignition, the heat exchanger 1 itself loses its ability to heat itself, the heating of the pipes in the hot water supply section, etc., and the rising temperature of the hot water discharge is poor as shown in FIG.

Therefore, in the present invention, the required capacity is calculated, and at the same time, the value that has been experimentally obtained from the outlet water temperature is added (subtracted) to the required capacity for a predetermined time, and the result is output. In addition, the rising characteristics of the tap water temperature will be greatly improved. In addition, by adopting this correction even in the transition period other than the start-up, even when the change in the combustion amount is a certain amount or more, the responsiveness of the tapping temperature in the transition period is significantly improved.

[0008]

[Effect of the device]

 As described above, according to the present invention, in the feedforward control, since the correction determined by the hot water temperature is performed during the transient period including the start-up, the responsiveness of the hot water temperature during the transient period is significantly increased. The effect of being able to improve is obtained.

[Brief description of drawings]

FIG. 1 is a system diagram of a water heater according to the present invention.

FIG. 2 is an outlet temperature characteristic diagram improved by the present invention.

FIG. 3 is a discharge water temperature characteristic diagram at the time of rising of the conventional feedforward control.

[Explanation of symbols]

 1 Heat Exchanger 2 Burner 3 Hot Water Thermistor 4 Water Supply Thermistor 5 Flow Rate Sensor 6 Fuel Supply Section (Variable) 7 Control Board 8 Computing Section 9 First Control Section 10 Second Control Section 11 Faucet

Claims (1)

[Claims for utility model registration] 1. A burner that burns fuel, a heat exchanger that heats water by the burner, a water supply thermistor that detects the temperature of water supplied to the heat exchanger, and a heat exchanger. A hot water thermistor for detecting the temperature of hot water from the, a flow rate sensor for detecting the flow rate of the water supply, a calculation unit for calculating the required capacity by multiplying the flow rate by the difference between the water temperature and the set temperature detected by the water supply thermistor, A first control unit that determines a correction value that is determined from the hot water temperature during the transitional period including the rising time, and the correction value is controlled in addition to the required capacity calculated by the calculation unit and the combustion amount that corresponds to the result. A water heater having a second control unit.