JPH07145929A - Hot water supplying apparatus - Google Patents

Abstract

PURPOSE:To prevent excess of a supply heat quantity by subtracting a mean excess heat quantity of a combustion heat quantity from actual start of combustion to detection of a flame and an overcombustion heat quantity at an initial time of starting residual continuous combustion in an ON/OFF cycle of combustion of an instantaneous type heat exchanger for heating a burner. CONSTITUTION:A controller 30 calculates necessary combustion ON and OFF times are calculated from a calculated necessary combustion heat quantity. Further, it calculates a time from actual start of combustion to a detection of a flame and an actual combustion ON time conforming to actual combustion, i.e., an ON time corresponding to a mean excess heat quantity of an overcombustion heat quantity at the initial time of starting combustion residually continuing even after the detection of the flame, previously stores it, calculates to subtract it from a combustion ON time, and sets the value as actual combustion ON time. Warm water heat exchanged with necessary combustion neat quantity in an instantaneous heat exchanger 10 is output to a hot water output tube 12, further suitably mixed with water from a bypass tube 13 by a mixing regulator 14 as warm water of a set hot water supply temperature, and fed to a hot water supply tube 15.

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.
The present invention relates to a hot water supply device that obtains hot water having a predetermined set hot water supply temperature by feedforward control by on-off cycle combustion of a burner as necessary.

[0002]

2. Description of the Related Art An instantaneous heat exchanger and a burner for heating the same are provided, continuous combustion is performed by proportional control during hot water supply, and when a relatively low hot water supply temperature is set, the set hot water supply is performed by on-off cycle combustion. Conventionally, there has been provided a hot water supply device that feed-forward controls temperature. The feedforward control by the on-off cycle combustion will be described with reference to FIG. 3 as well. The feedforward control is an operation control method performed when the set hot water supply temperature is relatively low, and the hot water supply temperature below a predetermined constant temperature is set. Then, from the set hot water supply temperature, the incoming water temperature, and the total flow rate, the necessary combustion heat quantity required to perform hot water supply at the set hot water supply temperature is calculated, and from the necessary combustion heat quantity, the necessary combustion heat quantity is obtained. Combustion on time t ₁ and combustion off time t ₂ required for
Is calculated, and the combustion on time t ₁ and the combustion off time t ₂
Cycle combustion in a relatively short cycle consisting of and is performed by feedforward control.

[0003]

However, in the above-described conventional hot water supply apparatus, since the combustion start time t ₁ is counted at the time of flame detection by the flame detector of the burner, the time from ignition to flame detection is Although the combustion was performed at t _{4, it} was not within the combustion on-time t ₁ . In addition, normally, during ignition, the combustion input is increased to ignite, so that the amount of heat corresponding to the shaded area in FIG. 3 eventually becomes the excess heat amount S, and the actual hot water supply temperature exceeds the set hot water supply temperature. There was a flaw.

Therefore, the present invention solves the above-mentioned drawbacks of the conventional water heater, and when performing feedforward control by on-off cycle combustion, even when the start of counting the combustion on-time is at the time of flame detection by the flame detector. ,
It is an object of the present invention to provide a hot water supply device that can supply hot water at a set hot water supply temperature accurately without supplying an excessive amount of heat.

[0005]

In order to achieve the above object, a hot water supply apparatus of the present invention has at least an instantaneous heat exchanger and a burner for heating the heat exchanger, and has a set hot water supply temperature and a water inlet. The required combustion heat quantity is calculated from the temperature and the total flow rate, and the necessary combustion on-time and combustion off time are calculated from the necessary combustion heat quantity, and feed-forward control is performed to obtain the necessary combustion heat quantity by on-off cycle combustion. In the hot water supply device, wherein the start time of counting the combustion ON time is set to the flame detection time by the flame detector after the actual combustion start time, the flame is detected by the flame detector from the actual combustion start. The average excess heat quantity consisting of the combustion heat quantity generated by the combustion up to the detection and the over-combustion heat quantity at the beginning of the combustion that remains after the flame detection is obtained in advance by experiments. It is characterized in that the actual combustion on time with a time to the on time was subtracted from the combustion on time which is calculated from the required amount of combustion heat which corresponds to the excess heat.

[0006]

According to the features of the present invention, an average amount of combustion heat generated by the combustion from the actual combustion start to the flame detection by the flame detector and an overcombustion heat amount at the beginning of combustion remaining after the flame detection is averaged. Excessive combustion is obtained by preliminarily obtaining an excess heat quantity by an experiment, and making the actual combustion on-time by subtracting the ON time corresponding to this average excess heat quantity from the combustion ON time calculated from the required combustion heat quantity. The calorific value is adjusted, and the calculated required calorific value of combustion can be surely output in a feed-forward manner in actuality, and hot water supply at an accurate set temperature can be secured.

[0007]

EXAMPLES The present invention will be described below based on examples.
FIG. 1 is an overall configuration diagram of a hot water supply device of the present invention, and FIG. 2 is a diagram illustrating an on / off cycle combustion operation in an embodiment device.

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.

In the above hot water supply apparatus, when a hot water supply device (not shown) is opened and operation is started, hot water is discharged from the water inlet pipe 11 to the hot water outlet pipe 12 through the heat exchanger 10, and the hot water from the hot water outlet pipe 12 is further discharged. On the other hand, the water from the bypass pipe 13 is appropriately adjusted by the mixing controller 14, and hot water adjusted to the set hot water supply temperature flows into the hot water supply pipe 15. The hot water supply control operation by the controller 30 will be described with reference to FIG. The heat exchange flow sensor 21
When the controller detects a minimum operating water amount (MOQ) or more, the controller 30 first determines the set hot water supply temperature set by the remote controller or the like and the incoming water temperature detected by the incoming water temperature sensor 22,
From 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, the required combustion heat quantity is calculated, and if the required combustion heat quantity is above a certain level, continuous combustion is performed. Then, the feedback control is performed by the feedforward control and the proportional control. When the required combustion heat quantity is less than a certain value, feedforward control by on-off cycle combustion is performed.

When performing feed-forward control by the on-off cycle combustion, the controller 30 uses the calculated required combustion heat quantity at a predetermined constant combustion input (combustion heat quantity) and at a predetermined constant cycle time. Combustion ON time t ₁ required to obtain the required combustion heat quantity
And the combustion off time t ₂ are calculated. The operation is burner 17
By comparing the combustion heat quantity in the case of continuous operation for the constant cycle time with the constant combustion input with the required combustion heat quantity, and determining the combustion on time and the combustion off time so that the necessary combustion heat quantity can be obtained exactly. You can

Further, the controller 30 further controls the performance described above.
Calculated combustion on time t₁Adapted to the actual combustion from
Actual combustion on time (t₁-T_Five) Is calculated. This fruit
The combustion ON time at this time depends on the flame detector from the actual start of combustion.
Until flame detection, that is, t in FIG. _FourBy burning in time,
Combustion heat S₁And combustion opening that continues after flame detection
Initial combustion heat S₂Average excess heat consisting of
S was previously obtained by an experiment, and S was compared with this average excess calorie S.
Corresponding on time t_FiveAnd calculate this in advance
Controller 30 and the controller 30 stores the required fuel.
Burning-on time t₁, Combustion off time t₂Calculate
After that, the combustion on time t₁From the on time t_Five
Is subtracted and the value (t₁-T_Five) Is actually
Combustion on time. That is, the actual combustion on time is
(T₁-T_Five) Time, the combustion off time is t₂And cycl
Le time is (t_Four+ T₁-T_Five+ T₂) And this actually
Combustion on time (t₁-T_Five) And combustion off time t₂And
Eggle time (t_Four+ T₁-T_Five+ T₂) By the way
Obtaining the required amount of combustion heat by performing fcycle combustion
You can The instantaneous heat exchanger 10 produces heat at the required combustion heat quantity.
The hot water that has been exchanged will flow out to the hot water outlet pipe 12, and then mixed.
The controller 14 mixes the water from the bypass pipe 13 appropriately.
Then, the hot water having the set hot water supply temperature is supplied to the hot water supply pipe 15.

[0012]

According to the present invention, which has the above-described structure,
According to the hot water supply device described in (1), in the case where the start time of counting the combustion on time is set to the flame detection time by the flame detector after the actual combustion start time, the flame detector starts from the actual combustion start. The average excess heat quantity consisting of the combustion heat quantity generated by combustion until the flame detection by and the over-combustion heat quantity at the beginning of the combustion that continues after the flame detection is obtained in advance by an experiment, and the on-time corresponding to this average excess heat quantity is obtained. Since the actual combustion on-time is calculated by subtracting the combustion on-time calculated from the required combustion heat from the actual combustion on-time, the start of counting the combustion on-time is counted by the flame detector when performing feed-forward control by on-off cycle combustion. Even when the flame is detected by, the supplied heat amount does not become excessive, and the calculated required combustion heat amount is reliably output in a feed-forward manner. Bets can be, can be ensured hot water accurate temperature setting.

[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 diagram illustrating an on-off cycle combustion operation in the embodying device.

FIG. 3 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. An instantaneous heat exchanger and a burner for heating the heat exchanger are provided at least, and a required combustion heat quantity is calculated from a set hot water supply temperature, an incoming water temperature, and a total flow rate.
A hot water supply device for calculating a required combustion on-time and a combustion off-time from the required combustion heat quantity to perform feedforward control so as to obtain the necessary combustion heat quantity by on-off cycle combustion.
When the flame detector detects the flame after the actual combustion start time, the amount of heat of combustion generated by the combustion from the actual combustion start to the flame detection by the flame detector and the remaining heat after the flame detection An average excess heat quantity consisting of the overburning heat quantity at the beginning of combustion was previously obtained by an experiment, and the actual ON time corresponding to this average excess heat quantity was actually subtracted from the combustion ON time calculated from the required combustion heat quantity. Hot water supply device, characterized in that the combustion on time is set.