JPH07269948A - Hot water supplying apparatus - Google Patents

Abstract

PURPOSE:To eliminate continuation of a state in which supply hot water exceeds a set supply hot water temperature due to a trouble of a mixing regulator. CONSTITUTION:A hot water supplying apparatus sets a time of starting counting of a combustion ON time in an ON and OFF cycle combustion operation to the time of detecting a flame by a flame detector after an actual combustion starting time. An excess heat quantity due to combustion heat quantity generated from the actual combustion start to a flame detection by the detector is previously obtained by an experiment, and stored in a controller 30. When a mixing regulator 14 is troubled, a time obtained by subtracting an ON time corresponding to the excess heat quantity from the combustion ON time calculated by a necessary combustion neat quantity is used as the combustion ON time in the case of calculating the combustion ON time by the controller 30.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water heater, and more particularly, it has an instantaneous heat exchanger and a burner for heating it.
As a combustion control method, proportional control combustion operation and on-off cycle combustion operation are selected according to the required heat of combustion, and mixing water is appropriately mixed with tap water to obtain hot water of a predetermined set hot water temperature. Regarding hot water supply equipment.

[0002]

2. Description of the Related Art A momentary heat exchanger and a burner for heating the heat exchanger are provided, and when the required combustion heat quantity is large, a continuous combustion operation by proportional control is performed, and when the required combustion heat quantity is not so large. Conventionally, a device for performing on-off cycle combustion operation by feedforward control has been provided. Conventionally, there has been provided a hot water supply device that obtains hot water having a predetermined set hot water temperature by mixing water by a mixing controller when the temperature of hot water supplied is higher than the set hot water temperature. An example of conventional on-off cycle combustion operation by feedforward control will be described with reference to FIG. 4 as well. In the on-off cycle combustion operation, a set hot water supply temperature is set by a combustion operation method performed when the required combustion heat amount is not too large. And the set hot water supply temperature, the incoming water temperature, and the total flow rate, the required combustion heat quantity required to perform hot water supply at the set hot water supply temperature is calculated, and further it is necessary to obtain the necessary combustion heat quantity from the required combustion heat quantity. The combustion on time t ₁ , the combustion off time t ₂ and one cycle time are calculated, and the on / off cycle combustion in a relatively short cycle consisting of the combustion on time t ₁ , the combustion off time t ₂ and one cycle time is feed forward. It is done by control.

[0003]

However, in the above-mentioned conventional hot water supply apparatus, in the case of the on-off cycle combustion operation, the count start time of the combustion on-time t ₁ is the time when the flame detector of the burner detects the flame. , the time t ₄ to time flame detection from ignited despite being made combustion, did not contain the into the combustion on-time t _1. Moreover, normally, during ignition, ignition is performed with a higher combustion input, so the amount of heat equivalent to the shaded area in FIG. 4 becomes the excess amount of heat S, and the actual outlet temperature from the instantaneous heat exchanger is There was a problem that became higher. For this problem, if there is a mixing controller, even if the hot water is heated to a slightly high temperature, it can be adjusted to the set hot water temperature by mixing water with the mixing controller, so there is no problem. If there is a failure, hot water supply will be continued without adjusting the temperature to the set hot water supply temperature.

Therefore, the present invention eliminates the above-mentioned drawbacks of the conventional water heater, and adopts a configuration in which feedforward control by on-off cycle combustion is performed, and combustion on-time counting is started at the time of flame detection by the flame detector. In this case, an object of the present invention is to provide a hot water supply device in which hot water supply does not continue in a state of exceeding the set hot water supply temperature even if the mixing adjuster fails.

[0005]

In order to achieve the above object, the hot water supply apparatus of the present invention uses a burner to heat water entering from a water inlet pipe through a momentary heat exchanger to discharge the water to a hot water outlet pipe, and at the same time, the water inlet pipe is provided. The hot water of a predetermined hot water temperature is supplied by appropriately mixing the water coming from the bypass pipe with a mixing regulator, and the burner combustion method is an on-off cycle combustion operation and a proportional control combustion operation. Is selected according to the required combustion heat quantity, and in the on-off cycle combustion operation, the further required combustion on-time and combustion off-time are calculated from the required combustion heat quantity calculated from the set hot water supply temperature, the incoming water temperature, and the total flow rate. The calculation is performed and feed-forward control is performed, and the combustion start time counting start time is set to the flame detection time by the flame detector after the actual combustion start time. In such a hot water supply device, an average excess heat quantity consisting of the combustion heat quantity generated from the actual combustion start to the flame detection by the flame detector and the over-combustion heat quantity at the beginning of the combustion which remains after the flame detection is experimentally determined in advance. Obtained and stored in the controller, when the mixing regulator fails, in the calculation of the combustion on-time by the controller, from the combustion on-time calculated from the required combustion heat quantity to the average excess heat quantity It is characterized in that the combustion ON time is obtained by subtracting the corresponding ON time.

[0006]

According to the features of the present invention described above, when the on-off cycle combustion operation is performed by the feedforward control, the actual combustion on-time is normally longer than the calculated combustion on-time, and the combustion heat quantity becomes excessive. As a result, hot water having a temperature higher than the preset hot water supply temperature is likely to be discharged, but the preset hot water supply temperature is quickly adjusted by the normal operation of the mixing controller. On the other hand, when the mixing regulator is out of order, the average excess calorific value is previously obtained by an experiment when the combustion on time, the combustion off time, and one cycle time are calculated by the controller, and the average excess heat is obtained. Since the on-time corresponding to the heat quantity is subtracted from the combustion on-time calculated from the required combustion heat quantity to obtain the actual combustion on-time, the excessive combustion heat quantity is adjusted, and as a result, the set hot water temperature is exceeded. It is possible to secure hot water supply at a temperature close to the set hot water supply temperature without continuing high-temperature hot water supply.

[0007]

EXAMPLES The present invention will be described below based on examples.
FIG. 1 is an overall configuration diagram of a hot water supply apparatus of the present invention, FIG. 2 is a flow chart showing an operation control operation mechanism by a controller, and FIG. 3 is a view explaining an on / off cycle combustion operation in an embodiment apparatus.

First, referring to FIG. 1, an overall schematic structure of an apparatus for carrying out the present invention will be described. The device is an instantaneous heat exchanger 10,
A water inlet pipe 11 for sending water to the heat exchanger 10, a hot water outlet pipe 12 for hot water heated by the heat exchanger 10, and a bypass pipe 13 for bypassing water from the water inlet pipe 11 to the hot water outlet pipe 12. A mixing controller 14 for mixing and adjusting water from the bypass pipe 13 and hot water from the hot water outlet pipe 12, and the mixing controller 14
And a hot water supply pipe 15 connected downstream thereof. The instantaneous heat exchanger 10 is heated by a burner 17 such as an oil burner. 21 is a heat exchange flow rate sensor, 22 is an incoming water temperature sensor, 23 is a hot water outlet temperature sensor, and 24 is a hot water supply temperature sensor. Further, 30 is a controller, and this controller 30 controls the entire apparatus, and includes a heat exchange flow rate sensor 21, an incoming water temperature sensor 2
2, input information from the hot water temperature sensor 23, hot water supply temperature sensor 24, other sensors, and also input the hot water supply temperature information set by a remote controller (not shown), perform the necessary calculations,
Send the required commands to the mixing regulator 14, burner 17, etc.

The operation control operation mechanism of the controller 30 in the hot water supply apparatus will be described with reference to FIGS. 2 and 3. Now, when the operation switch of the device is turned on, the hot water supply currant (not shown) is opened, so that the heat exchange flow sensor 21 flows at a flow rate equal to or higher than the minimum working water amount (MOQ) (Yes in S1) Is started. Hot water is discharged from the water inlet pipe 11 through the heat exchanger 10 to the hot water outlet pipe 12, and the hot water from the hot water outlet pipe 12 is appropriately adjusted by the mixing controller 14 with respect to the water from the bypass pipe 13 to set hot water. Hot water whose temperature is adjusted flows into the hot water supply pipe 15. When the heat exchange flow rate sensor 21 detects the minimum operating water amount (MOQ) or more, the controller 30 first causes the set hot water supply temperature set by a remote controller or the like (for example, 75 ° C. as a settable upper limit temperature).
Is set), the can body hot water temperature (the can body hot water upper limit temperature 77 ° C. is determined as the can body hot water temperature for the preset hot water supply temperature 75 ° C.) is determined by a predetermined method (S2). The required combustion heat quantity is calculated from this, the input water temperature detected by the input water temperature sensor 22, and the total flow rate calculated from the flow rate detected by the heat exchange flow rate sensor 21 and the initial distribution position of the mixing controller 14. Then, it is determined whether the on-off cycle combustion is performed by the feedforward control according to the magnitude of the required combustion heat amount (S3). When the required combustion heat quantity is large (NO in S3), continuous combustion of feedback control by proportional control combustion operation is performed (S
4).

When performing the feedforward control by the on-off cycle combustion (Yes in S3), the controller 30 obtains the required combustion heat quantity from the calculated required combustion heat quantity and the combustion input (combustion heat quantity) from the burner 17. The combustion-on time t ₁ , the combustion-off time t _2, and one cycle time required for the calculation are calculated (S5). Then, the controller 30 further checks whether the mixing controller 14 is normal (S6). This check can be done, for example, by the controller
The operation command is issued to the mixing controller 14 by 30,
This can be done by checking if the adjuster 14 has operated accordingly. When it is determined in step S6 that the mixing controller 14 is normal (YES in S6), the combustion on time t ₁ and the combustion off time t ₂ calculated above are calculated.
A normal on-off cycle combustion operation is performed according to the above and one cycle time (S7).

On the other hand, in step S6, the mixing controller
If 14 is determined to be a failure (especially, a failure due to fixing in the bypass pipe side fully closed state), the on / off time of the on / off cycle combustion calculated above is corrected (S
8). During operation, if the amount of working water becomes less than the minimum amount, the combustion is stopped (S9). An example of correction of the on / off time is shown in FIG.
To explain with the controller 30, from the calculated combustion on-time t _1, calculating the actual burn-on time adapted to the actual combustion (t ₁ -t _5). This actual combustion ON time is the amount of combustion heat S ₁ generated by the combustion from the actual combustion start to the flame detection by the flame detector, that is, t ₄ time in FIG. 2 and the initial combustion start overtime that remains after the flame detection. An average excess heat amount S including the combustion heat amount S ₂ is previously obtained by an experiment, an on-time t ₅ corresponding to the average excess heat amount S is calculated, and this is stored in the controller 30 in advance. When it is determined that the mixing controller 14 is out of order, the controller 30 calculates the combustion on-time t ₁ and the combustion off-time t ₂ from the required combustion heat quantity, and then further calculates the combustion on-time t ₁ to the on-time. t ₅ subtractive calculated, the actual combustion on time with the value (t ₁ -t _5). That is, the actual combustion on-time is (t ₁
-T ₅ ), the combustion off time is t ₂ , and the cycle time is (t ₄ + t ₁ −t ₅ + t ₂ ). The actual combustion on time (t ₁ −t ₅ ) and the combustion off time t ₂ And on / off cycle combustion is performed with the cycle time (t ₄ + t ₁ −t ₅ + t ₂ ). As a result, it is possible to obtain a heat quantity that is sufficiently close to the required combustion heat quantity. The correction can be performed without changing the cycle time. In this case, the combustion on time and the combustion off time are corrected.

[0012]

According to the present invention, which has the above-described structure,
According to the hot water supply apparatus described in (1), when the mixing controller is not in failure, the combustion heat amount becomes excessive, so that the tap water temperature fluctuates to the low temperature side due to variations in burner input and variations in heat exchanger efficiency. In this case, it is possible to prevent the temperature lower than the set hot water supply temperature from being discharged, and when the hot water is discharged at a temperature higher than the set hot water supply temperature, the mixing controller can be used to quickly set the hot water supply temperature. Adjustments can be made to Moreover, when the mixing regulator is out of order, the actual combustion on-time is subtracted from the combustion on-time calculated from the required combustion heat by subtracting the on-time corresponding to the excess heat from the combustion on-time.
Excessive heat of combustion can be adjusted, and as a result, high temperature hot water exceeding the set hot water temperature can be prevented from continuing.
It is possible to secure hot water supply at a temperature close to the set hot water supply temperature.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a hot water supply device of the present invention.

FIG. 2 is a flowchart showing an operation control operation mechanism by a controller.

FIG. 3 is a diagram illustrating an on-off cycle combustion operation in the embodying device.

FIG. 4 is a diagram illustrating an on-off cycle combustion operation in a conventional device.

[Explanation of symbols]

 10 Instantaneous heat exchanger 11 Inlet pipe 12 Outlet pipe 13 Bypass pipe 14 Mixing controller 15 Hot water supply pipe 17 Burner 21 Heat exchange flow rate sensor 22 Inlet water temperature sensor 23 Outlet water temperature sensor 24 Hot water temperature sensor 30 Controller

Claims (1)

[Claims] 1. The water entering from the water inlet pipe is heated by a burner through an instantaneous heat exchanger to discharge the water to the hot water outlet pipe, and the water coming from the water inlet pipe through the bypass pipe is appropriately mixed by a mixing adjuster. In this way, hot water of a predetermined hot water supply temperature is supplied, and as the combustion method of the burner, on / off cycle combustion operation and proportional control combustion operation are selected according to the required combustion heat quantity. In the combustion operation, the required combustion on-time and combustion off-time are calculated from the required combustion heat quantity calculated from the set hot water temperature, the incoming water temperature, and the total flow rate, and feedforward control is performed, and the counting start time of the combustion on-time is set. It is a hot water supply device that is designed to detect flames by the flame detector after the actual combustion start time, and An average excess heat quantity consisting of the combustion heat quantity generated up to the flame detection and the over-combustion heat quantity remaining at the beginning of combustion remaining after the flame detection was previously obtained by experiment and stored in the controller, and the mixing controller failed. In this case, in the calculation of the combustion on-time by the controller, the combustion on-time is calculated by subtracting the on-time corresponding to the average excess heat from the combustion on-time calculated from the required combustion heat quantity. Water heater.