JPH0674560A - Control method for hot water supply device - Google Patents

Abstract

PURPOSE:To prevent the generation of high temperature hot water supply or instability of hot water supply temperature by adjusting a water mixing control valve of a bypass line to a standby position during the suspension of hot water supply, and by setting a standby count number at the standby position with a timer and controlling the water mixing valve in conformity with the standby counter number. CONSTITUTION:Water in a water inlet line 10 is heated with a spontaneous heat exchanger 20 so that hot water is output to a hot water outlet line 30 while the water is mixed with a bypass line 40, thereby controlling the hot water to a specified temperature to supply the hot water. In this case, a controller 60 controls a burner 21 of the spontaneous heat exchanger 20 and a hot water control valve 41 of the bypass line 40 respectively based on each detection signal transmitted from an inlet temperature sensor 11, an inlet water flow rate sensor 12, an outlet hot water temperature sensor 31 and a hot water supply temperature sensor 51. More specifically, during the suspension of hot water supply, mixing water control valve 41 is adjusted to a standby position. A count number at the standby position is set with a timer. Furthermore, when hot water is to be supplied after the count number is zero, for example, the mixing water control valve 41 is adjusted to suit to positions equivalent to the water inlet temperature and hot water supply temperature.

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 hot water supply device in which hot water discharged through a heat exchanger is mixed with water by using a bypass to supply hot water at a predetermined hot water supply temperature.

[0002]

2. Description of the Related Art Various conventional water heaters of this kind, which adjust hot water discharged from an instantaneous heat exchanger to a preset hot water temperature by mixing water by bypass.

[0003]

However, a problem with the above-mentioned conventional water heater is that high-temperature hot water immediately after re-leasing due to post-boiling of the heat exchanger after hot water supply and low-temperature hot water resulting from excessive control corresponding thereto, etc. The tapping temperature was unstable.

Therefore, the present invention solves the above-mentioned drawbacks of the prior art, and reduces the occurrence of high-temperature hot water and the destabilization of hot water temperature due to post-boiling at the time of re-leaving hot water in a water heater of mixed water type. For the purpose of providing.

[0005]

In order to achieve the above-mentioned object, the present invention heats water from an inlet channel with an instantaneous heat exchanger to discharge the hot water into the outlet channel, and bypasses the bypass from the inlet channel. A method of controlling a water heater that connects to a water supply to mix water and adjust the temperature to a predetermined set hot water supply temperature to perform hot water supply, and when hot water supply is stopped, the bypass water mixing adjustment is performed at that time. While setting the valve to the standby position, the standby count number by the timer at the standby position is set from the hot water discharge temperature and the incoming water temperature from the instantaneous heat exchanger immediately before the hot water supply is stopped, and the down count by the timer is the water heater. It is set to a large value during the post-purge and a small value after the post-purge, and the water mixing adjustment valve is held in the standby position until the standby count number reaches zero, even if hot water supply is restarted. In hot water after it becomes zero is characterized by controlling the mixing water adjustment valve position of the bypass which is calculated from the hot water temperature and the incoming water temperature and the hot water set temperature from the moment the heat exchanger.

[0006]

According to the above feature of the present invention, during the normal hot water supply operation, the water mixing rate by the water mixing adjusting valve of the bypass is calculated from the set hot water supply temperature, the hot water discharge temperature from the instantaneous heat exchanger, and the incoming water temperature. The water mixing adjustment valve is driven to a position corresponding to the calculated water mixing rate. Then, when the hot water supply is stopped, the water mixing adjustment valve is driven to a predetermined standby position at that time,
At the same time, the standby count number is set in the controller, and the standby position is continuously held until the standby count number becomes zero. Therefore, if re-hot water supply is started before the standby count reaches zero, the water mixing adjustment valve is not immediately moved to the position calculated during normal operation, and the original water is not restored until the count reaches zero. Stops in the standby position. For a while after the hot water supply is stopped, high-temperature water due to post-boiling of the instantaneous heat exchanger can be re-exposed to the hot water, so the normal operation of the water mixture adjustment valve position is not adopted during that time, and the high-temperature water is not taken out as the predetermined standby position. Prevent it. The standby position may be, for example, the fully open position of the water mixing adjustment valve, but may be a position at which another appropriate amount of water can be mixed. As for the standby period, the standby count number is adopted, and the standby count number is automatically set from the data obtained experimentally in advance by the outlet hot water temperature and the incoming water temperature from the instantaneous heat exchanger immediately before the hot water supply is stopped. To be done. For the data, for example, the relationship between the difference between the hot water discharge temperature from the instantaneous heat exchanger immediately before the hot water supply is stopped and the incoming water temperature, the degree of post-boiling, and the duration thereof is obtained in advance through experiments. The down-counting of the standby count number by the timer is performed while increasing during the post-purge of the water heater and decreasing after the post-purge. Because air is blown during post-purging, the instantaneous heat exchanger is cooled faster by the air blow, while the cooling speed becomes slower after the end of post-purging, so the countdown number can be changed accordingly. Each down-count number is determined by an experiment in advance. This will result in a total waiting time that incorporates the effects of post-purging on post-boiling. The down count number is, for example, 2 counts / unit time during post-purging,
After completion of the post-purge, 1 count / unit time can be set.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an overall configuration diagram of a water heater in which the method of the present invention is carried out, FIG. 2 is a flow chart showing an example of control, and FIG. 3 is a diagram showing a temporal change of the position of a water mixture adjusting valve. .

In the water heater shown in FIG. 1, the water supplied through the water inlet 10 is heated by the instantaneous heat exchanger 20 and discharged into the hot water outlet 30. Bypass 40 from the water inlet 10 is a hot water outlet 30
It is connected to and is designed to mix water. An inlet temperature sensor 11 and an inlet flow rate sensor 12 are provided in the inlet passage 10. Further, the instantaneous heat exchanger 20 is provided with a burner 21. Further, the outlet temperature sensor 31 is provided in the outlet passage 30.
Further, a hot water supply temperature sensor 51 is provided in the hot water supply passage 50 downstream of the point 32 to which the bypass 40 of the hot water discharge passage 30 is connected, and a hot water supply temperature sensor 51 is provided in the bypass 40.
Is provided. 60 is a controller with a built-in microcomputer for controlling the entire water heater, which inputs information from each sensor 11, 12, 31, 51 and a command from a remote controller (not shown), performs a calculation according to a predetermined program, and outputs it to each unit 21, 41. The control signal of is output.

Next, a method of controlling the water heater by the controller 60 will be described with reference to FIGS. now,
When the hot water supply system (not shown) of the hot water supply passage 50 is closed from the hot water supply state, the hot water supply ends (NO in S1), and the valve position of the water mixing adjustment valve 41 is moved to a predetermined standby position (S2). This standby position is determined as a fully open position of the mixed water adjusting valve 41 or another position where an appropriate amount of water can be mixed by preliminary experiments. And the controller
Since the timer built in 60 has not yet set the standby count number at this time (No in S3), the controller 60 causes the hot water temperature input from the hot water temperature sensor 31 immediately before the hot water supply is stopped and the hot water input from the hot water temperature sensor 11 to enter. The standby count is set based on the temperature (S4). This standby count is obtained by a preliminary experiment and stored in the controller 60 in a form corresponding to the difference between the two so that the hot water temperature immediately before the hot water supply stop is higher and the hot water input temperature is lower. I'll keep it ready to retrieve.
When the waiting count number is set, countdown is started until the waiting count number becomes zero (S
5) And, during this countdown, whether or not the water heater is in the post-purge (the step of blowing air to discharge the exhaust gas in the burner 21 for a certain period after the burner 21 stops burning) The determination is made (S6), the down count number is increased during the post-purge (S7), and the down count number is decreased when the post-purge is not performed to count down. How to determine this down-count number is based on a preliminary experiment, by obtaining as a data how much the post-boiling temperature decreases while counting the unit counts and the degree to which the post-boiling temperature cools during the post-purge. , The down-count number during post-purging,
And, the down count number in other cases can be determined in advance.

If hot water supply is restarted before the standby count number reaches zero (YES in S1 and S9 in NO), the standby count number is irrespective of whether or not a new hot water supply temperature is set. The water mixing control valve 41 is continuously held at the standby position until the countdown to zero is reached (S10, S11). Then, when the standby count number becomes zero (Yes in S9), it is determined that the influence of post-boiling has disappeared, and the normal hot water supply operation is resumed. Based on the set hot water supply temperature, the hot water discharge temperature, and the incoming water temperature, Calculate the valve position (S
12) The valve 41 is moved to the calculated position (S13).

[0011]

According to the method of controlling a water heater according to the first aspect of the present invention, when the hot water supply is stopped, the bypass water mixing adjusting valve is on standby at that time. Along with the position, set the standby count number by the timer at the standby position from the hot water discharge temperature and the incoming water temperature from the instantaneous heat exchanger immediately before the hot water supply stop,
And the down count by the timer is large during the post-purge of the water heater and small after the post-purge,
Until the standby count reaches zero, the water mixing adjustment valve is held in the standby position even if hot water supply is restarted, and when hot water is supplied after the standby count reaches zero, the hot water outlet temperature from the instantaneous heat exchanger and the water input. Since the control is performed to the bypass water mixing adjustment valve position calculated from the temperature and the hot water supply set temperature, first, the standby count number is the hot water supply temperature and the hot water input temperature from the instantaneous heat exchanger immediately before the hot water supply is stopped. Since it is set from, it is possible to obtain the waiting time according to the state immediately before the hot water supply is stopped, and the time to prevent hot water supply after boiling water is not too long or too short can do. Therefore, hot water supply of post-boiling high temperature water and subsequent low temperature hot water supply can be appropriately prevented. Secondly, since the down-count number of the timer is changed according to the presence or absence of post-purge, it is possible to obtain an appropriate waiting time that incorporates the influence of the presence or absence of post-purge, and to supply hot water after boiling and Subsequent low-temperature hot water supply can be prevented more appropriately. Of course, until the standby count reaches zero, the water mixing adjustment valve is held in the standby position, and after that, the position of the water mixing adjustment valve is selected by normal calculation, so it is good depending on the time until re-hot water is discharged. The position of the mixed water adjustment valve can be controlled.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a water heater in which the method of the present invention is implemented.

FIG. 2 is a flowchart showing a control example of the method of the present invention.

FIG. 3 is a diagram showing a temporal change in the position of a water mixing control valve.

[Explanation of symbols]

 10 Inlet channel 11 Inlet temperature sensor 20 Instantaneous heat exchanger 21 Burner 30 Outlet channel 31 Outlet temperature sensor 40 Bypass 41 Water mixture adjusting valve 42 Drive section 50 Hot water channel 51 Hot water temperature sensor 60 Controller

Claims (1)

[Claims] Claim: What is claimed is: 1. Water from a water inlet is heated by an instantaneous heat exchanger to be discharged to a hot water outlet, and a bypass from the water inlet is connected to the hot water outlet to mix water to a predetermined set hot water temperature. A method of controlling a hot water supply device for adjusting hot water supply, wherein when hot water supply is stopped, a water mixing adjustment valve of the bypass is placed at a standby position at that time, and the moment immediately before the hot water supply is stopped. The standby count number by the timer at the standby position is set based on the hot water discharge temperature and the incoming water temperature from the heat exchanger, and the down count by the timer is set to be large during the post purge of the water heater and small after the post purge. , Until the standby count reaches zero, the water mixing adjustment valve is held in the standby position even if hot water supply is restarted, and when hot water is supplied after the standby count reaches zero, the instantaneous heat exchanger A method of controlling a water heater, characterized by controlling to a bypass water mixing adjustment valve position calculated from a hot water temperature, a hot water temperature, and a hot water supply set temperature.