JPH06249500A - Operation method for water heater - Google Patents

Abstract

PURPOSE:To prevent the temperature of hot water to be supplied from exceeding a set temperature of the hot water when the flow rate of hot water to be supplied is small by a method wherein even when the flow rate becomes less than the minimum working start flow rate, the cycle is continued, and even when the cycle is during the combustion-ON time, the combustion is not started, and when the flow rate becomes not more than the minimum working stop flow rate, the combustion is stopped. CONSTITUTION:The flow rate-wise condition regarding the combustion operation stop of a kerosene burner 10 is that a can body flow rate sensor 21 detects a flow rate not more than a minimum working stop flow rate. For the cycle combustion, a combustion-ON timer and combustion-OFF timer are respectively set in a controller 70, and the cycle combustion is continued even when the flow rate becomes not more than the minimum working stop flow rate, and the combustion is not started as long as the flow rate is less than the minimum working start flow rate. Also, even when the combustion is started, if the flow rate becomes not more than the minimum working stop flow rate before the combustion-ON time has passed, the combustion is stopped. By this method, even when the hot water supplying condition becomes such a state in which the flow rate varies around the minimum working flow rate, the temperature of the hot water to be supplied is prevented from gradually ascending.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention operates a burner with a constant capacity, and adjusts the required amount of heat accompanying the setting of the hot water temperature so that a predetermined amount of heat is obtained by cycle combustion by combining the combustion on time and the combustion off time. The operating method of the hot water heater.

[0002]

2. Description of the Related Art Conventionally, there has been provided a water heater which obtains a required amount of heat by a cycle combustion based on a combination of a calculated combustion on time and a combustion off time and supplies hot water having a set hot water temperature. On the other hand, with respect to the combustion of the burner in the water heater, the minimum operating flow rate is generally set, and the burner is not burned unless the flow rate exceeds this flow rate. Then, in the conventional hot water heater by the cycle combustion, when the flow rate becomes equal to or less than the minimum operation stop flow rate, the combustion off time timer is canceled, so that the next time the flow rate becomes equal to or more than the minimum operation start flow rate. Combustion started and there was no undershoot.

[0003]

However, in the above-described conventional method of operating a cycle combustion water heater, when the flow rate through the water heater changes vertically around a minimum operating flow rate when used at a small flow rate, When the combustion off time timer of the cycle combustion is canceled each time the flow rate becomes the minimum operation stop flow rate or less, the combustion is started each time the flow rate becomes the minimum operation start flow rate or more, resulting in a short combustion off time There is a problem that the number of times of turning on increases and the hot water supply temperature rises.

Therefore, the present invention solves the above-mentioned drawbacks of the prior art, and the hot water supply temperature exceeds the set hot water supply temperature even when the hot water supply flow rate is small and the flow rate changes vertically around the minimum operating flow rate. The purpose is to provide a method of operating a water heater that never goes.

[0005]

In order to achieve the above object, a method of operating a water heater according to the present invention is to operate a burner with a constant combustion capacity and to set a combustion on time so that a required heat quantity corresponding to a set hot water temperature is obtained. And the combustion off time are calculated to perform the cycle combustion operation, and the combustion start condition for the burner is to set the flow rate to be equal to or higher than the predetermined minimum operation start flow rate, and for the burner combustion stop condition. A method of operating a water heater in which the flow rate is below a predetermined minimum operation stop flow rate, and the flow rate is below the minimum operation start flow rate or below the minimum operation stop flow rate while the hot water supply operation switch is on. Also continues the cycle consisting of the combustion ON time and the combustion OFF time without stopping, and even if the cycle is during the combustion ON time, the flow rate is the minimum operation starting flow. A is the period is characterized in that so as to stop combustion if and flow without starting the combustion and below the minimum deactivation rate of less than.

[0006]

According to the above feature of the present invention, when the hot water supply scallop is opened while the hot water supply operation switch is on and the flow rate becomes equal to or higher than the minimum operation start flow rate, the burner combustion is started.
Then, the required heat quantity of the burner is calculated from the set hot water supply temperature, the incoming water temperature, and the incoming water flow rate, and further the cycle consisting of the combustion on time and the combustion off time to reach the calculated required heat quantity is calculated. By repeating the combustion ON and the combustion OFF in the set cycle, the normal hot water supply is performed at the set hot water supply temperature. Next, when the hot water supply flow rate is low and the flow rate frequently fluctuates up and down across the minimum operation start flow rate and the minimum operation stop flow rate, the combustion off timer is canceled every time the flow rate falls below the minimum operation stop flow rate in the conventional device. Therefore, even if the flow rate again becomes equal to or higher than the minimum operation start flow rate within a very short time, the combustion is restarted. However, in the present invention, the combustion off timer is not canceled even if the flow rate becomes equal to or less than the minimum operation stop flow rate, so that the combustion off time can be reliably ensured. When the combustion off time elapses, the combustion is turned on in principle, but even during the combustion on time, if the flow rate is less than the minimum operation start flow rate, the combustion is not started. Further, even when the combustion is on, if the flow rate is below the minimum operation stop flow rate, the combustion is stopped. As described above, in the present invention, while starting and stopping the burner combustion by the minimum operation start water amount and the minimum operation stop water amount, and by securing the combustion off time in the cycle combustion, the flow rate fluctuation near the minimum operation flow rate. It is possible to prevent the disadvantage of increasing the hot water supply temperature due to the above.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an overall configuration diagram of a hot water supply apparatus in which the method of the present invention has been carried out, and FIG.

In FIG. 1, reference numeral 10 denotes an instantaneous heating can body using a petroleum burner, which has a petroleum burner 11 and a heat exchanger 12 for heating water by the heat of combustion. Then, the water from the water inlet pipe 20 is supplied to the instantaneous heating can body 10, and the heated hot water is discharged to the hot water outlet pipe 30. A bypass pipe 40 is branched from the middle of the water inlet pipe 20, and the bypass pipe 40 and the hot water outlet pipe 30 are connected to a hot water supply pipe 60 via a water mixing controller 50. A can body flow rate sensor 21 and an incoming water temperature sensor 22 are provided on the downstream side of the point at which the bypass pipe 40 branches in the incoming water pipe 20. Further, hot water supply pipe 30 is provided with a hot water supply temperature sensor 31, and hot water supply pipe 60 is provided with a hot water supply temperature sensor 61. Reference numeral 70 denotes a controller of the hot water supply device, in which the hot water supply temperature is set by a remote controller (not shown) or the like, and the can flow rate sensor 21, the incoming water temperature sensor 22, the outgoing hot water temperature sensor 31,
By inputting information from the hot water supply temperature sensor 61, a predetermined operation command is output to the oil burner 11 of the instantaneous heating can body 10, the water mixture controller 50 and the like.

The flow rate condition for starting the combustion operation of the oil burner 10 is, of course, on the assumption that the hot water supply operation switch of the remote controller or the like is on, and the hot water supply pipe 60 (not shown) of the hot water supply pipe 60 is opened. By doing so, the can flow rate sensor 21 detects a flow rate _{equal to} or higher than the minimum operation start flow rate Q _ON . Further, the flow rate condition for stopping the combustion operation of the oil burner 11 is that the can flow rate sensor 21 detects the minimum operation stop flow rate Q _OFF or less.

The hot water supply operation starts when the petroleum burner 11 starts combustion when the hot water supply switch is turned on and water having the minimum operation start flow rate Q _ON or more flows through the can body flow rate sensor 21. The oil burner 11 is operated with a constant combustion capacity, the controller 70 calculates the required combustion heat quantity from the set hot water supply temperature, the incoming water temperature, and the total incoming water flow rate, and the combustion capacity of the oil burner 11 (the required combustion The combustion on-time x and the combustion off-time y for obtaining the required combustion heat quantity are calculated from (having the ability to exceed the heat quantity), and the cycle combustion is performed by the combination of the calculated combustion on-time x and the combustion off-time y. The hot water discharged from the heat exchanger 12 is temperature-controlled by the water mixing controller 50 as necessary, reaches a predetermined hot water supply temperature, and flows into the hot water supply pipe 60.

In the cycle combustion with the combustion on-time x and the combustion off-time y, a combustion on-timer and a combustion off-timer are set in the Coit roller 70, respectively.
Once the combustion on timer and the combustion off timer are set, the flow rate will be the minimum operation stop flow rate Q after that.
It is configured so that the combustion off timer is not canceled even if it becomes _OFF or less. Of course, the combustion on-timer is not canceled even when the flow rate becomes less than the minimum operation start flow rate Q _ON thereafter. The fact that the combustion on-timer and the combustion off-timer are not canceled means that the combustion off-time y is surely secured, but the combustion on-time x is surely turned on. However, as long as the flow rate is less than the minimum operation start flow rate Q _ON , combustion is not started during that time. Also even starts combustion, the flow rate before the combustion ON time x elapses becomes below the minimum operation stop flow rate Q _OFF, combustion is stopped. Thus, the operating method of the present invention is configured. The combination of the combustion on-time x and the combustion off-time y will be recalculated and changed by the controller 70 when the setting of the hot water supply temperature is changed or when the flow rate is changed.

The operation method of the present invention will be further described with reference to FIG. Now, after the combustion is once started, the minimum operation stop flow rate Q _OFF shown by the broken line Q _z in FIG.
When the above-mentioned average flow rate is stably flowing, the combustion of the oil burner 11 is also performed according to each timer by the combination of the calculated combustion on time x and combustion off time y as shown in (D). It is done stably. Next, when a small amount of hot water is supplied which causes a flow rate variation that crosses the minimum operation start flow rate Q _ON and the minimum operation stop flow rate Q _OFF as shown by the solid line in FIG. For example, it may occur when the water mixture controller 50 finely adjusts the water mixture amount at the time of small flow rate operation, or may occur due to fluctuation of the water flow rate itself from the water supply). First, in the case of changing the flow rate as shown by the solid line as described above, when canceling the combustion off timer when the flow rate becomes equal to or less than the minimum operation stop flow rate Q _OFF as in the conventional apparatus, the The combination of combustion ON and combustion OFF as shown in B) increases the number of combustion ON times and time, and the hot water supply temperature gradually rises above the set hot water supply temperature. That is, when the combustion is started at the time point A in FIG. 2A, the combustion off time y is passed after the combustion on time x, and the combustion off timer is started. However, since the flow rate falls below the minimum operation stop flow rate Q _OFF at the time point a, the combustion off timer is canceled at the time point a. Therefore, at the next time point c, the combustion is turned on again although the original combustion off time y has not yet elapsed. Then, such a process is repeatedly performed, and eventually, the same state as that in which combustion is performed in a short-time cycle is performed, and the temperature gradually rises above the set hot water supply temperature. Next, the case of the present invention is shown in FIG.
It will be described in accordance with (C) of. In the case of the present invention, when the combustion is started at the time point A in FIG.
After that, the combustion off time y is entered, and the combustion off timer starts to operate. Then, at the time point a, the flow rate falls below the minimum operation stop flow rate Q _OFF , but the combustion off timer is not canceled by this, and the time y continues to be effectively marked. Therefore, at the time point c, the combustion does not start, and at the time point d, Do not cancel the burn-off timer.
Then, the combustion off time y ends before the time point e, and the next combustion on time x starts, but at this time point, since the flow rate is less than the minimum operation start flow rate Q _ON , combustion is not started and the time point becomes the time point o. Combustion is started for the first time. And this (C)
Then, at the point in time, the combustion on-time x ends and the minimum operation stop flow rate Q _OFF becomes less than or equal to almost at the same time, but if it becomes the minimum operation stop flow rate Q _OFF or less during the combustion on time x, at that time point. Combustion is stopped. As described above, according to the present invention, although the actual combustion at the combustion on-time x may be reduced to some extent, the temperature rise can be prevented by protecting the cycle by the combustion on-time x and the combustion off-time y. Of course, since the minimum operation start flow rate Q _ON and the minimum operation stop flow rate Q _OFF are observed, the oil burner 11 will not be dry-fired.

In the above implementation method, a cycle consisting of the combustion on time and the combustion off time is set even if the flow rate is less than the minimum operation start flow rate or less than the minimum operation stop flow rate, regardless of the flow rate of hot water supplied. It continues without stopping, and even if the cycle is during the combustion on-time, the combustion is not started while the flow rate is below the minimum operation start flow rate, and the combustion is stopped if the flow rate is below the minimum operation stop flow rate. While it is so, only when the flow rate has been hot water is a flow above the minimum operating start flow Q _oN Moreover the following values relatively close to the lowest operation starting flow rate Q _oN, becomes such control operation If the flow rate drops below the minimum operation stop flow rate Q _OFF during hot water supply operation at a flow rate exceeding that, the combustion off timer is canceled accordingly. Good. The decrease in the flow rate from the high flow rate state to the minimum operation stop flow rate Q _OFF or less is considered to occur when the user normally closes the hot water tap. In this case, the combustion immediately starts in the next operation. The one started will help prevent undershoot.

[0014]

According to the method of operating the hot water supply apparatus of the present invention, the flow rate is less than the minimum operation start flow rate or the minimum while the hot water supply operation switch is on. Even if it becomes less than the operation stop flow rate, the cycle consisting of the combustion on time and the combustion off time continues without stopping, and even if the cycle is during the combustion on time,
Combustion is not started during the period when the flow rate is below the minimum operation start flow rate, and combustion is stopped when the flow rate is below the minimum operation stop flow rate. Even in the case of, it is possible to prevent the hot water supply temperature from gradually increasing due to frequent combustion on / off. Moreover, since the combustion conditions based on the minimum operation start water amount Q _ON and the minimum operation stop water amount Q _OFF are also observed, it is possible to prevent the oil burner from being dry-burned.

[Brief description of drawings]

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

FIG. 2 is a diagram illustrating a method of the present invention.

[Explanation of symbols]

 10 Instantaneous heating can 11 Oil burner 12 Heat exchanger 20 Water inlet pipe 21 Can body flow sensor 22 Water inlet temperature sensor 30 Hot water outlet pipe 31 Hot water outlet temperature sensor 60 Hot water inlet pipe 61 Hot water inlet temperature sensor 70 Controller

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoji Hatake, 32 Akashi-cho, Chuo-ku, Kobe, Hyogo Prefecture

Claims (1)

[Claims] 1. A burner is operated with a constant combustion capacity, and a cycle combustion operation is performed by calculating a combination of a combustion on time and a combustion off time so that a required heat quantity corresponding to a set hot water temperature is obtained. Also, in the operating method of the water heater, the combustion start condition is that the flow rate is greater than or equal to the predetermined minimum operation start flow rate, and the burner combustion stop condition is that the flow rate is less than or equal to the predetermined minimum operation stop flow rate. Therefore, while the hot water supply operation switch is turned on, even if the flow rate is less than the minimum operation start flow rate or less than the minimum operation stop flow rate, the cycle consisting of the combustion on time and the combustion off time is continued without stopping, and Even during the combustion ON time of the cycle, combustion is not started and the flow rate is less than the minimum operation stop flow rate during the period when the flow rate is less than the minimum operation start flow rate. For example, a method of operating a water heater characterized by stopping combustion.