JP3146770B2 - Water heater - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water heater having a combustor such as an oil combustor.

[0002]

2. Description of the Related Art Conventionally, in a hot water supply device such as an oil hot water supply device, after a combustion operation is stopped, cooling of a heat exchange can or a burner is performed.
In order to renew the exhaust gas, a post-purge operation for blowing air by a blower is performed. The time of the post-purge operation is generally a fixed time regardless of the conditions during the combustion operation.

[0003]

However, in the conventional hot water supply apparatus as described above, even when the combustion operation is performed for a long time with a large capacity, or when the combustion operation is performed for a short time with a small capacity, the post operation is difficult. Since the purging time is the same, if the post-purge time is determined in accordance with the large-capacity, long-time combustion, there is a drawback that undershoot occurs when re-watering under other combustion conditions. If the post-purge time is determined in accordance with the above, there is a drawback that overshoot and temperature rise inside the heat exchange can and the burner increase at the time of re-watering under other combustion conditions. Even when the post-purge time is determined, there is a problem that the above-described disadvantage occurs under other conditions, although the degree is different.

Accordingly, the present invention solves the above-mentioned drawbacks of the conventional hot water supply apparatus, prevents the occurrence of overshoot and undershoot at the time of re-starting hot water, and requires an increase in temperature after stopping the combustion inside the heat exchange can or the burner. It is an object of the present invention to provide a hot water supply apparatus having a post-purge operation that can sufficiently prevent the hot water supply.

[0005]

In order to solve the above-mentioned object, a water heater according to the present invention is provided with a heat exchange can body having a heat exchange tube for heating water sent from an inlet pipe and sending it to an outlet pipe. And a burner for performing combustion in the heat exchange can,
At least a controller that controls each part of the device,
The burner has a fuel ejection nozzle and a blower for blowing combustion air, and performs a post-purge operation in which only the air is blown into the burner and the heat exchange can by the blower after the combustion operation is stopped. a hot water supply apparatus which, that the time of the post purge operation by the blower, and configured to determine based on the combustion total heat by the heat of combustion and the combustion time of the combustion operation in the post-purge operation before starting Features.

[0006]

According to the feature of the present invention, when the hot water supply operation is started, the required amount of combustion heat is calculated from the set hot water supply temperature, the incoming water temperature, and the incoming water flow rate, and the combustion is started. And if the hot water set temperature or the incoming water flow rate is changed during the hot water supply operation,
The required amount of combustion heat is calculated again, and combustion is performed. Then, the combustion heat amount calculated during the operation and the time during which the combustion operation was performed are counted and stored in the controller . When the combustion is stopped, at that time, the combustion based on the stored combustion heat amount and the combustion time is performed. Post-purge based on total heat
The operation time is determined, and the post-purge operation is performed by the blower during the operation time. With the above-described configuration, the time of the post-purge operation after the end of combustion is determined in a manner proportional to the total amount of combustion heat received by the heat exchange can, the burner, and the like by the combustion performed before that. Therefore, regardless of the situation during the combustion operation, the amount of heat remaining in the heat exchange body and the burner after the completion of the cooling by the post-purge operation is adjusted to an appropriate constant amount. Therefore, the drawbacks of undershoot and overshoot at the time of re-watering are eliminated, and unnecessary postpurge operation more than necessary and wasteful power consumption due to it are prevented.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is an overall configuration diagram of an oil hot water supply apparatus showing an embodiment of the present invention,
FIG. 2 is a diagram for explaining a method of determining the post-purge time, and FIG. 3 is a diagram for explaining another method of determining the post-purge time.

Reference numeral 10 denotes a heat exchange can body, and reference numeral 20 denotes a burner. A combustion flame is blown from the burner 20 into the heat exchange can 10, thereby heating the heat exchange can 10. Exhaust gas generated in the heat exchange can 10 is exhausted from the exhaust port to the outside. Hot water is supplied by heating the water sent through the water inlet pipe 31 while passing through the finned heat exchange pipe 32 in the heat exchange can body 10 and discharging the hot water into the hot water pipe 33. The water inlet pipe 31 is provided with a water inlet temperature sensor 41 and a water amount sensor 42, and the water outlet pipe 33 is provided with a water outlet temperature sensor 43.

The burner 20 has a combustion tube 21 facing the inside of the heat exchange can 10, a petroleum fuel jet nozzle 22 facing the front of the combustion tube 21, and a blower 23.
Petroleum fuel is supplied to 22 via a fuel supply pump 24. Petroleum fuel, which has been sprayed into the combustion cylinder 21 from the petroleum fuel ejection nozzle and is sprayed, is burned together with the air blown from the blower 23, and becomes a combustion flame as a combustion flame.
It is blown out inside. Reference numeral 50 denotes a controller, which is a remote controller.
60, and inputs information from the water inlet temperature sensor 41, the water amount sensor 42, the tap water temperature sensor 43, and other sensors of the device, and based on the information, the blower 23, the fuel supply pump 24 , And issues predetermined operation commands to the other units of the apparatus.

Referring to FIG. 2, the control mechanism of the hot water supply operation by the controller 50 will be described. If the hot water supply curl (not shown) is opened while the main switch for the hot water supply operation is on, the controller 50 indicates that the water amount sensor 42 detects a water amount of a certain flow rate or more, issues a drive-on command to the blower 23, issues a spark-on command for the ignition electrode rod, and turns on the fuel supply pump 24. The fuel is jetted from the oil jet nozzle 22 in a spray state to start combustion. At the same time, the controller 50 controls the set hot water supply temperature input from the remote control 60 and the incoming water temperature sensor.
From the incoming water temperature input from 41 and the incoming water flow per unit time input from the water amount sensor 42, the required amount of combustion heat per unit time is calculated, and the fuel supply is performed so that the corresponding amount of fuel is supplied to combustion. Adjust the pump 24 and, optionally, the adjustable petroleum fuel jet nozzle 22. Then, when the set hot water supply temperature is changed or the amount of hot water is changed during combustion, the required amount of combustion heat is calculated again, and the fuel supply pump 24 and the oil fuel jet nozzle 22 are readjusted.

The controller 50 counts the amount of heat of combustion per unit time and the combustion time during the combustion operation and stores them. The amount of combustion heat stores the required amount of combustion heat per unit time calculated from the incoming water flow rate, the incoming water temperature, and the set hot water supply temperature by the controller 50, but in some cases, the outflow water temperature detected by the outflow water temperature sensor 43 and The calorific value calculated from the incoming water temperature and the incoming water flow rate can be used. Then, when a hot water supply curl (not shown) is closed, the controller 50 issues an off command to the fuel supply pump 24 by detecting the amount of water below a certain flow rate by the water amount sensor 42, thereby turning off only combustion. . Meanwhile, the blower
23 is continuously turned on, and the post-purge operation is started.

In the post-purge operation, the controller 50 determines the post-purge time. The determination of the post-purge time is made as follows. That is, referring also to FIG. 2, first, the controller 50 calculates the total combustion heat X from the stored combustion heat per unit time and the combustion time, and calculates the post-purge time Y in which this is stored in advance. The post-purge time Y is determined by applying the equation Y = AX + B. In the above formula Y = AX + B, A is a coefficient with respect to the total combustion heat X, and B is a base value. Preferred values of A and B are determined in advance by experiments.
The arithmetic expression Y = AX + B is a linear expression as an experimental expression,
The post-purge time Y calculated by this equation is a value on a straight line having a slope A as shown in FIG. The arithmetic expression determined experimentally need not be a linear expression. For example, the post-purge time Y may be calculated by a quadratic expression represented by Y = CX ² + B. Of course, also in this quadratic equation, a preferable value obtained experimentally is determined as the coefficient C.

In determining the post-purge time, preferred post-purge times for various combinations of the amount of combustion heat per unit time and the combustion time are obtained in advance by experiments, and are stored as a table as shown in FIG. For example, when the combustion amount per unit time is a and the combustion time is c, the post-purge time indicated by 4 may be selected as the post-purge time.

[0014]

According to the present invention, there is provided the above construction.
According to the hot water supply device described in the above, after the combustion operation is stopped, the air blower only blows the air into the burner and the heat exchange canister by the blower after performing the post-purge operation, the time of the post-purge operation by the blower, since a configuration determined based on the combustion total amount of heat due to combustion time and <br/> and combustion heat in the combustion operation in the post-purge operation before starting,
The time of the post-purge operation after the end of the combustion can be in a form proportional to the total amount of combustion heat received by the heat exchange can or the burner, etc., by the combustion performed before that, depending on the situation during the combustion operation. Regardless, the amount of heat remaining in the heat exchange can and the burner after the end of cooling by the post-purge operation can be adjusted to an appropriate constant amount. Therefore, it is possible to prevent unnecessary post-purging operation more than necessary, and to prevent useless power consumption due to the post-purging operation. Further, the disadvantages of undershoot and overshoot at the time of re-discharging can be eliminated.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an oil hot water supply apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining how to determine a post-purge time.

FIG. 3 is a diagram illustrating another method of determining a post-purge time.

[Explanation of symbols]

 10 Heat exchange can body 20 Burner 22 Petroleum fuel jet nozzle 23 Blower 31 Water inlet pipe 32 Heat exchange pipe 33 Hot water pipe 50 Controller

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F23N 5/20 101

Claims (1)

(57) [Claims] 1. A heat exchange can body provided with a heat exchange tube for heating water sent from an inlet pipe and sending it to a hot water pipe, a burner for performing combustion in the heat exchange can body, and an apparatus. At least a controller for controlling each part is provided, and the burner has a fuel ejection nozzle and a blower for blowing combustion air, and after the combustion operation is stopped, only the air is blown by the blower and the heat exchange can. a hot water supply apparatus that performs post-purge operation for blowing air into the body, the time of the post purge operation by the blower, the combustion total heat by the heat of combustion and the combustion time of the combustion operation in the post-purge operation before starting A hot water supply device characterized in that the hot water supply device is configured to be determined on the basis of: