Abstract: Provided is a hot-water supply device. A process performed by a control device of the hot-water supply device includes: a step of shifting an action mode of the hot-water supply device to an instant hot-water mode; a step of measuring an amount of water X; a step of determining that another tap interruption occurs when the amount of water X is equal to or greater than a basic flow amount Y+?; a step of stopping action of a circulation pump; a step of re-learning the amount of water X when the amount of water X is less than a basic flow amount Y??; a step of ending the instant hot-water circulation mode when an end condition of the instant hot-water mode is satisfied; and a step of measuring the amount of water X when the end condition of the instant hot-water mode is not satisfied.

Abstract: Provided is a hot-water supply device which stabilizes hot-water supply even at low water pressure. A process performed by a hot-water supply device includes: a step (S510) of detecting that hot-water supply performed by the hot-water supply device is stopped; a step (S520) of reading a set temperature of the hot-water supply from a memory; a step (S530) of calculating a target opening degree of a total water amount servo based on the read set temperature; a step (S540) of sending, to the total water amount servo, a command for setting an opening degree of a passage through which water flows from the total water amount servo into a heat exchanger to the target opening degree; and a step (S550) in which a stepping motor of the total water amount servo moves in response to the command.

Abstract: Provided is a hot-water supply device. A process performed by a control device of the hot-water supply device includes: a step of shifting an action mode of the hot-water supply device to an instant hot-water mode; a step of measuring an amount of water X; a step of determining that another tap interruption occurs when the amount of water X is equal to or greater than a basic flow amount Y+?; a step of stopping action of a circulation pump; a step of re-learning the amount of water X when the amount of water X is less than a basic flow amount Y??; a step of ending the instant hot-water circulation mode when an end condition of the instant hot-water mode is satisfied; and a step of measuring the amount of water X when the end condition of the instant hot-water mode is not satisfied.

Abstract: A hot water supply device includes: a first pipe connected to a water inlet; a flow detector detecting a flow of water in the first pipe; a heating mechanism heating the water; a second pipe through which warm water flows, connected to the first pipe via a third pipe; a circulating pump disposed in a path of the first pipe, sending the warm water in the third pipe toward the heating mechanism during operation; and a control device. Based on acceptance of an execution command of an instant hot water circulation mode, the control device operates the circulating pump, and, in response to a set hot water output temperature exceeding a limit temperature, adjusts a heating temperature of the heating mechanism, so that the temperature of the warm water becomes equal to or lower than the limit temperature.

Abstract: By a feedback arithmetic operation based on a temperature deviation, an input number is set which corresponds to a requested heat quantity generation, which is a controlled object, to a hot water supply apparatus. The temperature deviation is calculated by correcting a deviation of a tapping temperature with respect to a set hot water temperature with use of a Smith compensation temperature calculated by a Smith compensator for predicting a variation in a tapping temperature prior to an elapse of a dead time corresponding to a detection lag of the tapping temperature. The Smith compensator calculates a Smith compensation temperature to be used in the next control cycle based on the input scale number, the present Smith compensation temperature, and a time constant set in accordance with a flow rate of the hot water supply apparatus.

Abstract: A conversion factor learning unit successively updates a temperature conversion factor by learning a performance ratio of an output heat quantity with respect to an input scale number corresponding to a requested heat quantity generation to a hot water supply apparatus. The temperature conversion factor learned by the conversion factor learning unit is reflected in arithmetic operation of an FF scale number by a feedforward control unit and arithmetic operation of the FB scale number by the feedback control unit. An integral control in the feedback control unit is preferably turned off.

Abstract: By a feedback arithmetic operation based on a temperature deviation, an input number is set which corresponds to a requested heat quantity generation, which is a controlled object, to a hot water supply apparatus. The temperature deviation is calculated by correcting a deviation of a tapping temperature with respect to a set hot water temperature with use of a Smith compensation temperature calculated by a Smith compensator for predicting a variation in a tapping temperature prior to an elapse of a dead time corresponding to a detection lag of the tapping temperature. The Smith compensator calculates a Smith compensation temperature to be used in the next control cycle based on the input scale number, the present Smith compensation temperature, and a time constant set in accordance with a flow rate of the hot water supply apparatus.

Abstract: A conversion factor learning unit successively updates a temperature conversion factor by learning a performance ratio of an output heat quantity with respect to an input scale number corresponding to a requested heat quantity generation to a hot water supply apparatus. The temperature conversion factor learned by the conversion factor learning unit is reflected in arithmetic operation of an FF scale number by a feedforward control unit and arithmetic operation of the FB scale number by the feedback control unit. An integral control in the feedback control unit is preferably turned off.