JPH11337171A - Hot water supplier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To let out hot water having a temperature as near to a desired temperature as possible from the start of hot water delivery. SOLUTION: This device is provided with a bypass path 21 which connects a water entry path 5 with a hot water supply path 6 in condition that it bypasses a heat exchanger 2 for water heating and mixes the water from the water entry path 5 into the hot water from the hot water supply path and lets it out from a hot water delivery path 7, and a control means H which controls a burner 3, and the control means H usually executes combustion control in condition that water is passed to the heat exchanger 2, and also executes the warmth keeping combustion control to maintain the temperature of the hot water within the heat exchanger 2, at an objective temperature for keeping warmth, by combusting the burner 3, in condition that the water supply to the heat exchanger 2 is stopping. In this case, this is provided with an incoming water temperature detection means 9 to detect the temperature of the water supplied through a water entry path 5, and the control means H changes the objective temperature for keeping warmth so as to lower the objective temperature for keeping warmth more in the case where the detected temperature of incoming water is high than in the case where the detected temperature of incoming water is low.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger for heating water supplied to a hot water supply path by heating water supplied through a water supply path by combustion of a burner, and a heat exchanger for bypassing the heat exchanger. By connecting an entry waterway and a hot water supply path, a bypass path for mixing water from the water supply path with hot water from the hot water supply path and tapping out of the hot water path, and control means for controlling combustion of the burner are provided. The control means executes normal combustion control in which combustion of the burner is started as water flow to the heat exchanger is started, and combustion of the burner is stopped as water flow is stopped. In addition, in a state in which the flow of water to the heat exchanger is stopped, the heat-retention combustion control for burning the burner to maintain the temperature of the hot water in the heat exchanger at the target temperature for heat retention is performed. The present invention relates to a water heater configured.

[0002]

2. Description of the Related Art A hot water supply apparatus as described above performs a warming combustion control during a period from the stoppage of tapping from a tapping path to a start of tapping again, and the tapping is started again at the beginning of tapping. It is intended to prevent low-temperature hot or cold water from flowing out of the road, and this heat retention target temperature is conventionally changed only on the basis of the hot water target temperature, and the temperature of water supplied through the water inlet passage is changed. It was not changed on the basis of (for example, Japanese Patent Application Laid-Open No. 10-9672).

[0003]

Therefore, in the conventional hot water supply apparatus, a part of the water from the water inlet is heated, and the heated hot water is mixed with the water from the bypass to discharge the hot water. When the temperature of the water supplied from the water supply channel through the channel is high, the temperature of the hot water discharged from the water supply channel at the beginning of the hot water supply increases, and conversely, the temperature of the water supplied from the water supply channel via the bypass channel is increased. If the temperature of the hot water is low, the temperature of the hot water discharged from the hot water path at the beginning of hot water starts to drop,
Hot water at a desired temperature may not be discharged from the beginning of tapping.

Therefore, the present invention has been made in view of such a point, and an object of the present invention is to provide a hot water supply device capable of supplying hot water at a desired temperature as much as possible from the beginning of hot water supply. is there.

[0005]

To achieve this object, according to the first aspect of the present invention, there is provided an incoming water temperature detecting means for detecting a temperature of water supplied through an incoming water channel, and the control means comprises: Based on the water temperature detected by the water temperature detection means, the target temperature for heat retention is changed so that the target temperature for heat retention is lower when the detected water temperature is higher than when the detected water temperature is lower. ing. Therefore, when the incoming water temperature is high, the tapping temperature is lowered by lowering the target temperature for keeping warm, and conversely, when the incoming water temperature is low, the target temperature for keeping warm is raised to bring the tapping temperature close to the desired temperature. Thus, even when the incoming water temperature is low or high, it is possible to supply hot water at a desired temperature as much as possible from the beginning of the tapping.

According to the second aspect of the present invention, there is provided a temperature setting means for setting the temperature of hot and cold water discharged from the hot water supply passage, and the control means detects the temperature set by the temperature setting means and the temperature detected by the incoming water temperature detection means. The target temperature for heat retention is configured to be changed based on the incoming water temperature. Therefore,
The target temperature for tapping can be appropriately set to the temperature required by the user by the temperature setting means, and the usability is improved, and not only is the incoming water temperature detected by the incoming water temperature detecting means, but also the set temperature by the temperature setting means. Since the target temperature for heat retention can be changed based on this, it is possible to tap water having a temperature close to the target temperature for tapping required by the user from the beginning of tapping.

According to the third aspect of the present invention, the temperature detecting means for detecting the temperature of hot water in the hot water supply path or the heat exchanger is provided when the flow of water to the heat exchanger is stopped. The control means starts burning the burner when the temperature detected by the temperature detecting means is equal to or lower than the lower limit set temperature, and stops the burner combustion when the detected temperature is equal to or higher than the upper limit set temperature, and executes the heat retaining combustion control. Based on the incoming water temperature detected by the incoming water temperature detecting means,
It is configured to change the lower limit set temperature or the upper limit set temperature. Therefore, when the set time for starting the heat retention has elapsed since the passage of the water to the heat exchanger was stopped, the burner started to perform the warmed combustion. As compared with what is executed, the warming combustion control can be performed based on the temperature of the hot water in the hot water supply path or the heat exchanger at the beginning of hot water supply, so that the warming combustion control is accurately performed. It is possible to more reliably discharge hot water at a temperature close to the desired temperature from the start of hot water supply, and furthermore, the burner is intermittently burned based on the lower limit set temperature and the upper limit set temperature. The running cost can be reduced as compared with the case where the burner is continuously burned so as to maintain the temperature.

According to the fourth aspect of the present invention, when the control means executes the insulated combustion control, based on the detected incoming water temperature by the incoming water temperature detecting means at the time of the normal combustion control executed before that. The target temperature for heat retention is configured to be changed. Therefore, the target temperature for heat retention is changed based on the detected incoming water temperature in a state in which water is flowing through the heat exchanger, not in a state in which water flowing through the heat exchanger is stopped. Thus, the target temperature for heat retention can be changed based on an accurate temperature of incoming water in passing water through the heat exchanger, instead of the temperature of incoming water heated by the above method.

According to the fifth aspect of the present invention, when the control means executes the warm combustion control, if the normal combustion control has not been performed within a set time before that, the control means executes the warm combustion control. The target temperature for heat retention is changed on the basis of the incoming water temperature detected by the incoming water temperature detecting means at that time. In other words, when the set time has elapsed since the execution of the normal combustion control, the target temperature for warming is not determined based on the water inlet temperature detected by the water temperature detecting means in the warming combustion control but on the basis of the water inlet temperature detected in the normal combustion control. Since the temperature is changed, it is possible to change the target temperature for heat retention based on the detected temperature of the incoming water that is more suitable for the heat-retention combustion control even if the detected temperature of the incoming water varies with time.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A hot water supply apparatus according to the present invention will be described with reference to the drawings. As shown in FIG. 1, the hot water supply apparatus includes a hot water supply unit K for heating supplied water to supply hot water to the tap 7a, a control unit H as control means for controlling the operation of the hot water supply unit K, H is provided with a remote control operation unit R for instructing operation information to H.

The hot water supply unit K comprises a heat exchanger 2 for water heating provided in the combustion chamber 1, a gas combustion type burner 3 for heating the heat exchanger 2, and the like.
There is also provided a fan 4 through which the combustion air is passed from the upstream side and whose ventilation amount can be changed and adjusted. The heat exchanger 2 has a water inlet 5 to which water is supplied from, for example, a household water supply, and a hot water supply 6 for supplying hot and cold water.
Are connected to each other, and a bypass 21 that connects the water inlet 5 and the hot water supply 6 in a state of bypassing the heat exchanger 2 is provided, and the hot water from the hot water supply 6 and the water from the bypass 21 are mixed and manually operated. A hot water tap 7 for tapping the hot water tap 7a is connected to the hot water supply path 6 and the bypass 21. In addition, hot water supply path 6
The hot water supply path 6 is connected to the connection point between the hot water supply path 7 and the bypass path 21.
Mixing valve 22 that mixes hot and cold water from water with water from bypass path 21 at a constant mixing ratio and supplies the mixture to tap water path 7.
Is provided.

A water flow rate sensor 8 for detecting the flow rate of water to the heat exchanger 2 and a water temperature thermistor 9 for detecting a temperature of water supplied through the water flow path 5 are provided in the water path 5. A tap water thermistor 10 is provided in the tap water path 7 to detect the temperature of tap water from the tap tap 7a, and a tap temperature as temperature detecting means for detecting the temperature of tap water in the heat exchanger 2. A thermistor 23 is also provided.

The fuel supply passage 11 for the burner 3 is provided with an electromagnetically operated on-off valve 12 for intermitting fuel supply, and an electromagnetically operated gas amount control valve 13 which is capable of changing and adjusting a fuel supply amount (burning amount of the burner 3). In the vicinity of the burner 3, an igniter 14 for executing an ignition operation for the burner 3 and a frame rod 15 for detecting whether or not the burner 3 is ignited are provided, respectively.

The remote control operation unit R includes an operation switch 16 for instructing start and stop of the operation of the hot water supply unit K, a temperature setting switch 17 as a temperature setting means capable of changing and setting a target temperature for tapping, a tapping temperature and tapping temperature. The display unit 18 includes a display unit 18 for displaying a target temperature, an operation lamp 19 for displaying an operation state, a combustion lamp 20 for indicating that the burner 3 is in a combustion state, and the like.

The control section H is provided with a microcomputer and comprises a normal combustion control means 100 for executing normal combustion control during tapping, a warming combustion control means 101 for executing warming combustion control during tapping standby, Each of the setting means 102 for changing and setting the target temperature is provided in the form of a control program.

The normal combustion control means 100 includes a hot water supply section K
In the state where is set to the operating state, the combustion of the burner 3 is started with the passage of water to the heat exchanger 2 and the passage of water to the heat exchanger 2 is stopped. Normal combustion control for controlling the combustion of the burner 3 so as to stop the combustion of the burner 3 and adjusting the combustion amount of the burner 3 so that the hot water temperature becomes the hot water target temperature when water flow to the heat exchanger 2 is detected. Is configured to execute.

Specifically, after the operation state is set in accordance with the ON operation of the operation switch 16, the water flow rate detected by the water flow rate sensor 8 in response to the opening operation of the hot water tap 7a exceeds the set water flow rate. Then, the ventilation operation by the fan 4 is started, the intermittent valve 12 is opened, and the gas amount control valve 13 is opened and adjusted to the ignition gas amount, and the ignition operation of the burner 3 is performed by the igniter 14. Then, the ignition of the burner 3 is confirmed by the frame rod 15.

Thereafter, the tap water temperature is determined based on the detection information of the inlet water temperature thermistor 9, the tap water temperature thermistor 10, the flow rate sensor 8, and the information of the tap water target temperature set by the temperature setting switch 17. The amount of combustion of the burner 3 required to reach the hot water target temperature is calculated. Then, while adjusting the gas amount control valve 13 so that the gas amount corresponds to the obtained combustion amount, the fan 4
The feedforward control for adjusting the ventilation amount of the fan 4 is performed so that the ventilation amount of the fan 4 becomes an appropriate combustion state with respect to the adjustment gas amount, and the detected temperature of the tapping temperature thermistor 10 is set to the target temperature for tapping. Then, a feedback control for finely adjusting the opening of the gas amount adjusting valve 13 is executed. In this way, a part of the water from the water inlet channel 5 is heated by the heat exchanger 2 and mixed with the water from the bypass channel 21,
Hot water of the target temperature for hot water is supplied from the hot water tap 7a.

The insulated combustion control means 101 is in a standby state in which hot water is stopped, that is, when the operation switch 16 is turned off.
If the temperature detected by the hot water thermistor 23 becomes lower than or equal to the lower limit set temperature in a state where the water is not supplied to the heat exchanger 2 after the N operation, the combustion of the burner 3 is started and the hot water thermistor 2 is started.
When the detected temperature of the burner 3 becomes equal to or higher than the upper limit set temperature, the combustion control for stopping the combustion of the burner 3 is executed.

More specifically, when the temperature detected by the hot water thermistor 23 falls below the lower limit set temperature in a state where the flow of water to the heat exchanger 2 is stopped, the intermittent valve 12 and the gas amount adjusting valve 13 are turned off. The combustion of the burner 3 is started by opening the valve, and when the detected temperature of the hot water thermistor 23 becomes equal to or higher than the upper limit set temperature, the intermittent valve 12 and the gas amount adjusting valve 13 are closed to stop the combustion of the burner 3. It is configured. And
The hot water temperature thermistor 23 is provided in a portion of the hot water passage in the heat exchanger 2 where the hot water is easily heated by the combustion of the burner 3 and the hot water temperature is liable to drop during standby for hot water supply.

The setting means 102 changes and sets the lower limit set temperature and the upper limit set temperature as the heat retention target temperatures based on the tapping temperature by the temperature setting switch 17 and the incoming water temperature detected by the incoming water temperature thermistor 9. Is configured. More specifically, as for the lower limit set temperature, the tapping target temperature Ts set by the temperature setting switch 17 is set as the lower limit set temperature. The upper limit set temperature is, for example, 14 deg when the detected inlet water temperature is 8 ° C. or lower, 10 deg when the detected inlet water temperature is higher than 8 ° C. and 18 ° C. or lower, and the detected inlet water temperature is 18 ° C.
A temperature obtained by adding a preset temperature α corresponding to the detected inlet water temperature to the outlet water target temperature Ts, such as 8 deg when the inlet water temperature is higher than 28 ° C. and below, and 6 deg when the detected inlet water temperature is higher than 28 ° C. Ts + α is set as the upper limit set temperature.

The setting means 102 operates the temperature setting switch 1 while the water flow to the heat exchanger 2 is stopped.
7, when the tapping target temperature Ts is changed, the temperature before and after the change is compared, the lower one is selected as the tapping target temperature Ts, and the selected tapping target temperature Ts is selected.
The lower limit set temperature and the upper limit set temperature are set based on.
In addition, when the warming combustion control is executed, the detected incoming water temperature by the incoming water temperature thermistor 9 is always updated by updating and storing the incoming water temperature detected by the incoming water temperature thermistor 9 in the normal combustion control executed immediately before. Based on the incoming water temperature detected by the incoming water temperature thermistor 9 during the passage of water into the heat exchanger 2, the target temperature for keeping warm can be changed, and the warming combustion control can be executed accurately.

As described above, the lower limit set temperature and the upper limit set temperature in the insulated combustion control are changed based on the incoming water temperature detected by the incoming water temperature thermistor 9, so that the temperature of the water supplied through the water inlet passage 5 is high. Even when the temperature is low, hot water having a temperature close to the hot water supply target temperature Ts can be discharged from the hot water path 7 from the beginning of the hot water supply.

Next, the control operation of the control unit H will be described with reference to FIG.
This will be described with reference to the flowchart of FIG. First, after the power is turned on and the operation switch 16 is turned on, the detection value of the water flow rate sensor 8 exceeds the set water flow rate and the water flow rate to the heat exchanger 2 is increased with the opening operation of the hot water tap 7a. When (water flow) is detected, the detected incoming water temperature of the incoming water temperature thermistor 9 at that time is stored, and the setting flag is turned off.
The normal combustion control is executed (steps 1 to 4). That is,
When the burner 3 is ignited and the ignition of the burner 3 is confirmed by the flame rod 15, the tapping temperature detected by the tapping temperature thermistor 10 becomes the tapping target temperature Ts set by the temperature setting switch 17. Next, the combustion amount of the burner 3 and the ventilation amount of the fan 4 are controlled (steps 5 and 6).

With such control, when the tap 7a is closed, the detection value of the water flow sensor 8 becomes smaller than the set water flow, and the flow of water (water flow) to the heat exchanger 2 is detected. It is executed until the operation switch 16 is turned off or the operation switch 16 is turned off (steps 6 to 8). That is, heat exchanger 2
When the flow of water (water flow) to the air is no longer detected or the operation switch 16 is turned off, the intermittent valve 12 and the gas amount adjusting valve 13 are closed to stop the burner 3 from burning, and then the fan 4 The operation is also stopped (steps 7 to 9).

When the operation switch 16 is turned ON,
In a state where water flow (water flow) to the heat exchanger 2 is not detected (steps 1 and 2), if the setting flag is OFF,
Set the lower limit temperature and upper limit temperature and set the setting flag to O.
N is performed (steps 10 to 12). That is, for the lower limit set temperature, the tapping target temperature Ts set by the temperature setting switch 17 is set as the lower limit set temperature, and for the upper limit set temperature, a preset temperature α is added to the tapping target temperature Ts. Temperature Ts + α is set as the upper limit set temperature.

Then, when the tapping target temperature Ts is changed by the temperature setting switch 17 in a state where the flow of water to the heat exchanger 2 is stopped, the temperature after the change is lower than the temperature before the change. In this case, the lower limit set temperature and the upper limit set temperature are changed and set based on the changed tapping target temperature Ts (steps 13 to 15). That is, similarly to the above-described setting, for the lower limit set temperature, the tapping target temperature Ts set by the temperature setting switch 17 is set as the lower limit set temperature, and for the upper limit set temperature, the preset temperature α is set. The temperature Ts + α added to the tapping target temperature Ts is set as the upper limit set temperature.

After setting the lower limit set temperature and the upper limit set temperature in this way, the detected temperature Tk of the hot water thermistor 23 is set.
When the temperature becomes equal to or lower than the lower limit set temperature Ts, the heat retention combustion of the burner 3 is started to execute the heat retention operation (steps 16 and 17),
If the flow of water (water flow) to the heat exchanger 2 is not detected and the operation switch 16 is kept ON and the detected temperature Tk of the hot water thermistor 23 becomes higher than the upper limit set temperature Ts + α (steps 18 to 20), the operation is interrupted. The valve 12 and the gas amount adjusting valve 13 are closed to stop the warming combustion of the burner 3 to stop the warming operation, and thereafter, stop the operation of the fan 4 (step 21). If water flow (water flow) to the heat exchanger 2 is detected during the heat-retaining combustion of the burner 3 (step 18), the detected incoming water temperature of the incoming water temperature thermistor 9 at that time is updated and stored, and the above-described operation is performed. Normal combustion control is performed. Further, when the operation switch 16 is turned off during the insulated combustion of the burner 3, the intermittent valve 12 and the gas amount adjusting valve 13 are closed to stop the insulated combustion of the burner 3, and then the operation of the fan 4 is also started. It is stopped (steps 19 and 21). [Another Embodiment] (1) In the above embodiment, the lower limit set temperature in the insulated combustion control is the hot water outlet target temperature Ts, and the upper limit set temperature is the hot water outlet target temperature Ts corresponding to the incoming water temperature detected by the incoming water temperature thermistor 9. Temperature Ts + to which α is added
Although it is set to be changed to α, the lower limit set temperature is set to a temperature Ts-β obtained by subtracting the temperature β corresponding to the detected inlet water temperature from the tapping target temperature Ts, and the upper limit set temperature is set to the tapping target temperature Ts. You may do so. Further, in the above embodiment, the upper limit set temperature and the lower limit set temperature are changed based on the incoming water temperature detected by the incoming water temperature thermistor 9 and the tapping target temperature Ts by the temperature setting switch 17. Is not provided, and when the hot water outlet target temperature Ts is set in advance, the temperature may be changed based only on the incoming water temperature detected by the incoming water temperature thermistor 9.

(2) In the above embodiment, when the detected temperature Tk of the hot water thermistor 23 falls below the lower limit set temperature Ts,
When the warming combustion of the burner 3 is started and the detected temperature Tk reaches the upper limit set temperature Ts + α, the warming combustion of the burner 3 is stopped to burn the burner 3 intermittently. The burner 3 may be continuously burned so as to maintain the temperature Tk at the target temperature for heat retention.

(3) In the above-described embodiment, when performing the warming combustion control, the warming target temperature is changed based on the incoming water temperature detected by the incoming water temperature thermistor 9 at the time of the normal combustion control executed immediately before. I try to do
It is not always necessary to change based on the detected incoming water temperature at the time of the immediately preceding execution.For example, within the set time after executing the normal combustion control, the normal combustion control performed during the set time is not required. The target temperature for heat retention may be changed based on the incoming water temperature detected by the incoming water temperature thermistor 9. That is, when executing the warming combustion control, it is sufficient that the warming target temperature is changed based on the incoming water temperature detected by the incoming water temperature thermistor 9 in the normal combustion control executed before that. If the normal combustion control is not executed within the set time before the execution of the heat retention combustion control, the target temperature for heat retention is determined based on the input water temperature detected by the water temperature thermistor 9 when the heat retention combustion control is executed. May be changed.

(4) In the above embodiment, a hot water thermistor 23 for detecting the temperature of hot water in the heat exchanger 2 is provided as a temperature detecting means, and the detected temperature T of the hot water thermistor 23 is used.
Although the warming combustion control is executed based on k, a hot water supply temperature thermistor for detecting the temperature of hot water in the hot water supply passage 6 is provided, and the warming combustion control is executed based on the detected temperature of the hot water supply temperature thermistor. You may.

(5) In the above embodiment, the mixing valve 22 for mixing hot and cold water at a constant mixing ratio is provided at the connection point of the hot water supply path 6, the hot water supply path 7, and the bypass path 21, but the hot water supply path A mixing valve that can change and adjust the mixing ratio of hot water and water in 7 may be provided.
When changing and adjusting the mixing ratio of hot water and water in the hot water path 7, an opening degree adjustment valve may be provided in the bypass path 21 to perform the change and adjustment.

[Brief description of the drawings]

FIG. 1 is an overall schematic diagram of a water heater.

FIG. 2 is a flowchart showing a control operation of a control unit.

FIG. 3 is a flowchart showing a control operation of a control unit.

[Explanation of symbols]

 Reference Signs List 2 heat exchanger 3 burner 5 water inlet 6 hot water supply path 7 hot water outlet 9 incoming water temperature detecting means 17 temperature setting means 21 bypass path 23 temperature detecting means H control means

Claims (5)

[Claims] 1. A water heating heat exchanger for heating water supplied through a water inlet through combustion of a burner to supply hot water to a hot water supply passage; and a heat exchanger for bypassing the heat exchanger. A bypass path that mixes water from the water inlet path with hot water from the hot water supply path and taps the hot water from the hot water path; and control means for controlling combustion of the burner. A normal combustion control for starting the combustion of the burner as the flow of water to the heat exchanger is started, and stopping the combustion of the burner as the flow of the water is stopped, executes the heat exchange. A hot-water supply device configured to execute heat-retention combustion control for burning the burner and maintaining the temperature of hot water in the heat exchanger at a target temperature for heat retention in a state in which water supply to the heat exchanger is stopped. Supply through the water inlet Water temperature detection means for detecting the temperature of water to be supplied, wherein the control means keeps the temperature higher when the detected water temperature is higher than when the detected water temperature is lower based on the water temperature detected by the water temperature detector. A hot water supply apparatus configured to change the heat retention target temperature so as to lower the temperature target temperature. 2. A temperature setting means for setting a temperature of hot or cold water discharged from the hot water supply path, wherein the control means is configured to control the temperature based on a temperature set by the temperature setting means and an incoming water temperature detected by the incoming water temperature detecting means. The hot water supply apparatus according to claim 1, wherein the hot water retention target temperature is changed. 3. A temperature detecting means for detecting a temperature of hot or cold water in the hot water supply path or the heat exchanger in a state in which water flow to the heat exchanger is stopped, When the temperature detected by the detection means is equal to or lower than the lower limit set temperature, the combustion of the burner is started,
When the detected temperature is equal to or higher than the upper limit set temperature, the combustion of the burner is stopped to perform warming combustion control, and based on the incoming water temperature detected by the incoming water temperature detecting means, the lower limit as the warming target temperature, The hot water supply apparatus according to claim 1, wherein the hot water supply apparatus is configured to change the set temperature or the upper limit set temperature. 4. When the control means executes the warming combustion control, the warming target temperature is determined based on the incoming water temperature detected by the incoming water temperature detecting means in the normal combustion control executed before that. The hot water supply apparatus according to any one of claims 1 to 3, wherein the hot water supply apparatus is configured to change the temperature. 5. The incoming water temperature detecting means for executing the warm combustion control if the normal combustion control is not executed within a set time before the control means executes the warm combustion control. The hot water supply apparatus according to claim 4, wherein the hot water retention target temperature is changed based on the detected incoming water temperature.