JP2001241761A - Control method of heating for fluid heating instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the durability of a heat exchanger or the like by avoiding the continuation of local heating of the heat exchanger and avoid the local existence of high-temperature fluid in a hot-water supplying circuit upon the independent heating operation of a reheating circulation circuit, in a hot-water supplier provided with a reheating circulation function having a one-boiler two-circuit type heat exchanger. SOLUTION: Upon the independent operation of the reheating circulation circuit 3, heating positions with respect to the heat exchangers 12, 32 are changed sequentially in such a manner that a first solenoid valve 76 is opened at first to ignite a first combustion burners group 71 comprising 6 sets of burners, then, the first solenoid valve is closed and a second solenoid valve 77 is opened to ignite a second combustion burners group 71. Subsequently, the second solenoid valve is closed and a third solenoid valve 78 is opened to ignite a third burners group 71 comprising two sets of burners, and, the third solenoid valve is closed and the first solenoid valve is opened to ignite the first combustion burners group sequentially at every times when a switching control signal is received from a controller. The switching control signal is outputted when the integrated value of heat amount for the heat exchanger due to combustion operation has arrived at the set value of heat amount.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid used for controlling heating of a heat exchanger provided in a fluid heating device such as a water heater, a water heater having a reheating circulation function or a water heater having a hot water heating function. The present invention relates to a heating control method for a heating device.

[0002]

2. Description of the Related Art In a single-function water heater, a plurality of combustion burners, each of which can perform a single combustion operation, are provided for supplying heat for heating to a fin type heat exchanger. Is performed by changing and adjusting the number of combustion burners that perform combustion operation.

Further, in a water heater with a reheating circulation function in which a plurality of combustion burners are provided for a one-can two-circuit heat exchanger in which a heat transfer tube for a hot water supply and a heat transfer tube for a bath are shared using heat absorbing fins. A heating control method is also known in which a combustion burner different from the one burned last time is burned each time a heating operation to the heat exchanger is started (for example, Japanese Patent Application Laid-Open No. Hei 4-186052). Gazette).

[0004]

However, in the above-mentioned conventional heating control method, when performing a heating operation for the heat exchanger accompanying the combustion operation, only a part of the plurality of combustion burners is continued. If the combustion operation continues, the heat exchanger will be locally heated, and the durability of the heat exchanger may be deteriorated early.

That is, in the above-mentioned single-function water heater, the tapping temperature continuously set by the user is relatively low. Only one of the burners will be fired. In this case, only the portion of the heat exchanger corresponding to the combustion burner whose combustion has been operated is locally supplied with heat, which is a factor of deteriorating the durability of the heat exchanger. In this case, even if the combustion burner that performs the combustion operation is changed every time the heating operation to the heat exchanger is started as proposed in the above publication, the same combustion is constantly performed during the time when the user is using the hot water. As a result, the burner is operated by combustion, which also results in deterioration of the durability of the heat exchanger.

On the other hand, in the above-described water heater with the reheating circulation function, the same as in the case of the single-function water heater described above, regardless of whether the hot water supply operation or the reheating circulation operation is performed. In addition, the durability of the heat exchanger may be deteriorated. Moreover, during one of the single heating operations, the fluid inside the heat transfer tube stays in the other circuit in the other circuit, so that the fluid in the heat transfer tube may partially become excessively high in temperature. In particular, when performing reheating circulation operation, there is a possibility that hot water in a high-temperature state may be locally present in the heat transfer pipe for hot water supply, which is problematic.In addition, the reheating circulation operation has a relatively high combustion output. Due to the low temperature, only a part of the combustion burners are operated by combustion, which is a factor of deteriorating the durability of some of the combustion burners in addition to the heat exchanger.

The present invention has been made in view of such circumstances, and an object of the present invention is to prevent the local heating state of the heat exchanger from being continued and to reduce the durability of the heat exchanger and the like. Is to improve. In addition, in a heating device in which a heat exchanger is a two-circuit type can and a plurality of functions are combined, when a single heating operation of only one circuit is performed, a locally high-temperature fluid exists in the other circuit. The purpose is to avoid the occurrence of the situation.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention is to provide a heat exchanger in which, when the demand for the degree of heating is relatively small, the heat is partially added to the heat exchanger. Attention is paid to the fact that it is only necessary to average the amount of heat applied to the heat exchanger as a whole by sequentially changing the heated position to be heated at a predetermined timing.

More specifically, the present invention provides a fluid heating apparatus in which a heating source is provided along a heat exchanger, and a heating operation of a fluid passing through the heat exchanger is performed by controlling a heating operation of the heating source. During the heating operation, the heating source is partially heated during the heating operation, and the heated position where the heat exchanger is heated is sequentially changed to a different position during the heating operation. In this case, it is a specific matter to execute a switching control for sequentially switching the portions of the heating source to be heated to be operated.

Here, the above-mentioned "heating source" is not particularly limited as long as it can provide a heat quantity for heating to the heat exchanger, and is particularly a heating source arranged along the heat exchanger. The heat exchanger is configured so as to be partially heat-operable, and the heating operation of each part thereof partially adds heat to the heat exchanger. Such a heating source may be configured to have, for example, two or more heating units that can be individually heated. As the above-mentioned "heating unit", for example, LPG (liquefied petroleum gas) or LNG (liquefied natural gas)
A combustion burner that imparts the calorific value by burning a gaseous fuel such as gas fuel or a liquid fuel such as light oil or kerosene is provided. Two or more combustion burners are provided along the heat exchanger and the heating is performed. The source may be configured. More specifically, examples of the combustion burner include a combustion tube type gas burner in the case of gaseous fuel, and a gun type oil burner of multistage switching type which performs diffusion combustion in the case of liquid fuel.

[0011] The above-mentioned "fluid heating device" means that a fin type heat exchanger in which a pipe to which a fluid is supplied passes through a large number of fins is externally heated by the above-mentioned heating source. For example, a single-function water heater having a 1-can 1-circuit heat exchanger, or a 1-can 2-circuit heat exchange in which a hot-water supply circuit and a circulation heating circuit are respectively passed. A hot water heater with a reheating circulation function having a water heater or a hot water heater with a hot water heating function can be used.

In the above-mentioned "switching control", when the heating source has two or more heating units as described above, the switching of the part to be heated may be performed by selecting from the two or more heating units. . For example, taking the case where two or more combustion burners (heating units) described above are arranged along a heat exchanger,
If there are two combustion burners, 1
The switching of the combustion operation (heating operation) may be performed alternately for each burner. In the case of three burners, the switching of the combustion operation may be repeated for each burner. After the two cylinders are operated for combustion, the remaining two cylinders or one selected from the remaining two cylinders is operated for combustion, and the switching of the combustion operation may be repeated thereafter. When there are a large number of four or more combustion burners, the switching of the combustion operation may be repeated every arbitrary number of burners, or any two or more of the total number of combustion burners may be used. Switching of combustion operation is repeated by grouping (grouping), between arbitrary groups, or between arbitrary groups and arbitrary ones, or between arbitrary two or more groups. You may do so. Here, the switching control is performed so that different portions of the heating source are heated before and after the switching of the combustion operation, that is, after the switching, a combustion burner different from that before switching is operated. It is preferable to perform the switching control so as to improve the durability of the combustion burner, but it is preferable to perform the switching control so that some of the combustion burners are operated in a redundant manner before and after the switching. Is also good. For example, when there are three or more combustion burners, any two are burned before switching, and after switching, another one or two or more different from the arbitrary two are combined with the arbitrary two or more. This is the case where one of the books is burned together. Even in such a case, the durability of the combustion burner (heating unit) can be improved as compared with the case where the combustion operation (heating operation) is continuously continued during the heating operation.

The switching control according to the present invention is preferably performed continuously from the start to the end of the heating operation. However, at the time of starting the heating operation, for example, all the heating sources are once heated. The present invention includes a case in which the above-described switching control is performed after the heating start control is performed.

In the case of the present invention described above, the switching control is performed in which the heating source is partially heated and the portions to be heated are sequentially switched, so that the heat received by the heating operation. The heated position of the exchanger is changed each time the switching is performed. This eliminates the situation where the same heated position of the heat exchanger is continuously heated locally during the heating operation of the fluid heating device, and the heating of the heat exchanger is averaged as a whole. Become. As a result, the durability of equipment such as a heat exchanger and a heating source is improved.

In particular, when the present invention is applied to a fluid heating device having a one-can, two-circuit type heat exchanger, in addition to the improvement of the durability by eliminating the above-mentioned local overheating, it is possible to improve the durability of one of the circuits during the single heating operation. In this case, even if the fluid in the other circuit is in a stagnant state, the fluid receives an average amount of heat over the entire heat exchanger range. Thus, it is possible to reliably avoid a situation where the fluid in the other circuit is locally excessively heated.

There are the following two methods for setting the switching timing of the switching control in the present invention.

As a first method, the amount of heat applied to the heat exchanger from the heated portion of the heating source is integrated with time, and when the integrated amount of heat reaches a predetermined set amount of heat. May be used to execute the switching control. In this case, no matter how the part of the heating source for switching the heating operation is selected, the change timing of the heated position with respect to the heat exchanger is such that the integrated heat amount value for each heated position is equal to the heat amount set value. Since the switching is performed at the time of arrival, averaging of the heating for the entire heat exchanger is reliably realized, and the durability of equipment such as the heat exchanger is further improved.

Here, in order to "accumulate the amount of heat over time", for example, in the case of burning fuel, the relationship between the amount of fuel supplied and the amount of combustion heat generated when burning the fuel is experienced. The fuel supply amount per unit time is detected from the operation control information of the heating source, and the detected fuel supply amount is multiplied by the elapsed time detected by an elapsed time measuring means such as an electronic timepiece. What should I do? Or you may make it measure directly by the calorie measuring means, such as a calorimeter.

As the above-mentioned "heat amount setting value", it is preferable to set the heat amount value as small as possible from the viewpoint of avoiding local overheating and averaging the heating. It may be determined by the relationship. Further, as the above-mentioned "heat amount setting value", one or more values may be determined in advance, or an optimum value may be determined based on various parameter values detected during the heating operation. . When setting the optimum value, for example, a detected flow rate value or a detected temperature value of a fluid passing through a heat exchanger to be heated is used as a parameter value, and a relational expression that defines these parameter values in relation to each parameter value is used. May be obtained by arithmetic processing, or an optimum heat value may be extracted from a map or a table in which a plurality of heat value values are determined in advance in relation to the above parameter values.

As a second method relating to the switching timing, the switching control is executed when the operation continuation time of the heated portion of the heating source reaches a predetermined set operation continuation time. I just need. In this case, since the switching of the switching control is performed using only the operation continuation time as a parameter, the operation according to the present invention can be easily obtained while performing simple heating control.

Here, the "set operation duration" is, for example, a uniform time value (for example, 10 seconds).
c) may be set, or a plurality of types of time values determined according to the heat amount range for each portion of the heating source may be set, and the time value corresponding to that portion may be applied to each portion to be heated. Is also good. For example, the heat amount of a certain portion of the heating source is 21,000 k
10 sec for J / h (5,000 kcal / h)
c, the heat quantity is 42,000 kJ / h (10,000 kJ / h);
cal / h), it may be determined as 5 seconds.

As a heating control device for realizing the above-described heating control method, for example, when switching control is performed based on a heat amount set value, a portion of the heating source which is selectively heated is operated. A calorie monitoring means for detecting the calorie given to the heat exchanger and integrating with time, and a calorie comparing means for comparing whether or not the calorie integrated value by the calorie monitoring means has reached a predetermined calorie set value, Switching control means for switching and changing the heating operation of the heating source when the calorific value comparing means determines that the integrated calorific value has reached the calorific value set value may be provided. Here, the calorie monitoring means includes a calorie detector that detects the amount of heat generated per unit time by detecting a fuel supply amount and the like, and integrates the amount of heat generated per unit time detected from this detector over time. And a heat quantity integrating unit. Further, for example, in the case of performing the switching control based on the set operation continuation time, the count is started by selectively performing the heating operation from among the heating sources, and the switching signal is output when the set operation continuation time is reached. And a switching control means for changing the portion of the heating source to be heated by receiving the output of the switching signal from the timer means.

[0023]

As described above, according to the heating control method for a fluid heating device according to the present invention, during the heating operation of the fluid heating device, the same position to be heated of the heat exchanger is partially and partially. The occurrence of a situation in which the heat exchanger is continuously heated can be reliably avoided, and the heating of the heat exchanger can be reliably averaged as a whole. Thus, local overheating of the heat exchanger can be eliminated, and the durability of equipment such as the heat exchanger and the heating source can be improved.

In particular, when the heat exchanger is a one-can, two-circuit type heat exchanger, in addition to improving the durability of the equipment by eliminating the local overheating, when one of the circuits is operated alone, It is possible to reliably avoid a situation in which the fluid in the other circuit is locally excessively heated.
Particularly, a remarkable effect can be obtained when the circulating heating circuit is operated alone, and when the operation of the hot water supply circuit is started later and the internal fluid is discharged to the outside through curan or the like, high-temperature water with cold water interposed therebetween is used. Can be reliably prevented from being heated in a sandwich state, and the user does not feel uncomfortable.

[0025]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a water heater having a reheating circulation function as a fluid heating device to which a heating control method according to an embodiment of the present invention is applied. This water heater with a reheating circulation function includes a one-can, two-circuit heat exchanger and a combustion tube-type combustion burner using LNG as fuel as a heating source. In the present embodiment, the switching control according to the present invention is executed at the time of the independent heating operation of the after-heating recirculation circuit 3 described later.

In the figure, 2 is a hot water supply circuit, 3 is a bathtub 4
A reheating circuit as a recirculating heating circuit for reheating the hot water in the bath, a bath pouring circuit 5 for pouring hot water from the heat exchange circuit 2 for hot water supply to the bathtub 4, and a heating control device 6 The hot water supply circuit 2 and the reheating circuit 3 are heated by heat exchange with combustion heat in a common heating can 7.

The hot water supply circuit 2 includes a water inlet pipe 11 connected to a water pipe and a heat exchanger 1 disposed in the heating can 7.
2, a tapping pipe 13 and a bypass pipe 14,
The pouring pipe 13 of the bath pouring circuit 5 is connected to the tapping pipe 13 in addition to the general hot water supply pipe 16 to the curan 15.
The incoming water pipe 11 is provided with an incoming water temperature sensor 18 and an incoming water flow rate sensor 19, while the outgoing water pipe 13 is provided with an outgoing water temperature sensor 20 and a hot water supply amount control valve 21.

The reheating circuit 3 includes a bath 4
And a heat exchanger 32 disposed in the heating can 7 for circulating hot and cold water. The reheating circuit 31 includes a feed pipe 31a for flowing the hot water heated by the heat exchanger 32 into the bath 4 and a return pipe 31b for returning the hot water in the bath 4 to the heat exchanger 32. The return pipe 31b includes a circulation pump 33, a water flow switch 34, a bath temperature sensor 35, and a water level detection sensor 3.
6 are interposed. In FIG. 1, reference numeral 37 denotes a drain plug for maintenance.

Furthermore, the pouring pipe 17 of the bath pouring circuit 5
Is provided with a pouring flow sensor 51, a pouring control valve 52, and a pair of check valves 53, the downstream ends of which are connected to both the outgoing pipe 31a and the return pipe 31b. The return pipe 31b and the pouring pipe 17 are connected via a three-way switching valve 54.

In addition, as shown in detail in FIG. 2, the heating can body 7 has a plurality of (11 in the example in the figure) combustion burners as heating units below the heat exchangers 12, 32. 7
, 71,... And a gas supply pipe 72 connected to a fuel gas supply source to supply fuel gas to each combustion burner 71.
And a blower 73 arranged below the combustion burners 71 to supply combustion air. The gas supply pipe 72 is provided with a main gas solenoid valve 74 as a main valve and an electromagnetic gas proportional valve 75 for adjusting a gas supply amount in this order from the supply source side. The plurality of combustion burners 71, 7 are located downstream of the gas supply pipe 72.
A plurality (three in the illustrated example) of solenoid valves 76, 7 for selectively switching gas supply to 1,.
7, 78 are provided.

When the first solenoid valve 76 is opened, six combustion burners 71, 71,... (In FIG. 1 and FIG. 2, for the sake of illustration, each group is collectively indicated as "71"). The same applies hereinafter). When the second solenoid valve 77 is opened, three combustion burners 71, 71, 71 are burned. When the third solenoid valve 78 is opened, two combustion burners 71, 71 are burned. It is supposed to be. That is, a total of 11 combustion burners 71, 71,... Are divided into three groups of six, three, and two, and the combustion operation (heating operation) of the first to third combustion burner groups 71 is performed. The switching is performed by opening and closing the first to third three solenoid valves 76, 77, 78. The combustion operation is started based on the ignition of the ignition plug or the like in addition to the opening operation of each of the electromagnetic valves 76, 77, 78.

The above water heater with reheating circulation function is MP
The operation is controlled by a controller 6 having a U, a memory, and the like.
As shown in the figure, a hot water remote controller (hot water remote controller) 60 for inputting various commands by the user and displaying a status are connected to a bath remote controller (bath remote controller) 61. The controller 6 includes a hot water supply control unit 62 that controls the operation of the hot water supply circuit 2.
And a bath controller 6 for controlling the operation of the reheating circuit 3
A switching control unit 64 for averaging the heating of the heat exchangers 12 and 32 by controlling the switching of the combustion operation of each combustion burner group 71 in cooperation with the hot water supply control unit 62 and the bath control unit 63; It has.

For example, when the user inputs a set value of a tapping temperature to the hot water supply remote controller 60, the user opens the caran 15 and the incoming water flow sensor 19 detects the flow rate that is equal to or more than the minimum working water amount. , The gas proportional valve 75 is first opened to a relatively small opening after the pre-purge,
One of the electromagnetic valves 76 to 78 is opened to start combustion of the corresponding combustion burner group 71. Thereafter, the gas proportional valve 7 is controlled so that the required amount of heat is obtained according to the set value of the tapping temperature.
By adjusting the opening degree of the valve 5 or opening the three solenoid valves 76 to 78, feedback control is performed so that the temperature of the hot water discharged from the tapping pipe 13 becomes the set value. . As a result, the hot water at the set hot water temperature flows through the hot water supply pipe 13 and the hot water supply pipe 16 so that
Hot water. Then, when the user closes the caran 15 and the water input amount sensor 19 detects the minimum working water amount, the solenoid valves 74, 76 to 78 and the gas proportional valve 75 are set.
Are closed, and the combustion of each combustion burner group 71 is stopped.

In the bath controller 63, for example, when a user inputs a pouring command for filling the bathtub 4 into the bath remote controller 61, the bath controller 63 receives the output of the pouring command. The pouring control valve 52 is opened by the section 63, and the solenoid valves 74, 76 to 78 and the gas proportional valve 75 are opened in the same manner as described above, and the combustion operation of each combustion burner group 71 is started to control the pouring. Is started. This allows
Hot water of a predetermined set temperature heated by the heat exchanger 12 flows through the tapping pipe 13 and the pouring pipe 17 to the outgoing pipe 31 of the circulation path 31.
a to be poured into the bathtub 4. The pouring amount at this time is detected by the pouring flow rate sensor 51, and the pouring control is terminated by detecting the predetermined water level as the bathtub water level of the bathtub 4 by the water level sensor 36. In this pouring control, the three-way switching valve 54 is closed by closing the heat exchanger 32 side of the return pipe 31b and ending the bathtub 4 of the same return pipe 31b.
Switching control is performed such that the side and the pouring pipe 17 are communicated with each other. When the water level sensor 36 detects the predetermined water level, switching control is performed so that the bathtub 4 side as well as the heat exchanger 32 side of the return pipe 31b is closed.

When a reheating command is input to the bath remote controller 61, the three-way switching valve 54 is turned on by the bath control unit 63 having received the output of the reheating command.
When the circulation pump 33 is operated after the side is closed and the front and back of the return pipe 31b are switched so as to communicate with each other, and the water flow switch 34 is turned on accordingly, the following combustion control is started. That is, the bath control unit 63 first opens the gas proportional valve 75 to a predetermined opening for reheating, for example, an opening at which the combustion output becomes 42,000 kJ / h (10,000 kcal / h). If the temperature detected by the bath temperature sensor 35 is not too low as compared with a predetermined set temperature when the bath temperature in the bathtub 3 is detected by detecting a sudden rise in the water level by the water level detection sensor 36, the additional The opening of the gas proportional valve 75 is set to 21,000 kJ / h (5,000) so that the temperature rise of the hot water due to the baking does not become too hot.
kcal / h) can be switched to an opening smaller than the above, which is a combustion output of kcal / h).

Next, any one of the three solenoid valves 76 to 78 is opened, and the corresponding combustion burner group 71 is operated for combustion. Thereafter, based on the switching control signal output from the switching control unit 64, the one solenoid valve 7 that has been
6, 77 or 78 is closed, the other solenoid valve is opened, and the corresponding combustion burner group 71 is operated to perform combustion.

For example, when the first solenoid valve 76 is first opened and the first combustion burner group 71 composed of six burners is operated,
Upon receiving the switching control signal, the first solenoid valve 76 is closed to stop the combustion of the first combustion burner group 71, while the second solenoid valve 77 is opened to open the third combustion burner group 7 consisting of three.
1 is burned. Further, upon receiving the next switching control signal, the second electromagnetic valve 77 is closed to stop the combustion of the second combustion burner group 71, and the third electromagnetic valve 78 is opened to open the second third combustion burner group 71. Is operated. Further, upon receiving the next switching control signal, the third
While the solenoid valve 78 is closed to stop the combustion of the third combustion burner group 71, the first solenoid valve 76 is opened to open the first
The combustion burner group 71 is caused to perform a combustion operation, and thereafter, each time the switching control signal is received, the above-described switching of the combustion operation is sequentially repeated.
When the combustion operation is switched, an ignition device (for example, an ignition electrode or the like) is provided for each combustion burner group 71, and ignition is performed every switching operation. Combustion burner group 7 for combustion operation this time
After burning to 1, combustion burner group 71 of the previous combustion operation
May be closed.

By the above combustion control, reheating is performed in which the hot and cold water in the bathtub 4 is heated while circulating through the circulation path 31 with the heat exchanger 32.
By detecting a predetermined temperature, the original gas solenoid valve 7
4. Solenoid valve 76, 77 or 7 that is open at that time
8, and the gas proportional valve 75 is closed, and the reheating control is stopped.

The switching control section 64 for outputting the switching control signal includes a calorific value integrating section 641 and a calorific value comparing section 642. Then, the hot water supply control unit 62 and the bath control unit 6
Receiving each control information from 3 and reheating circuit 3
It is determined whether or not the single heating operation is performed. If the single heating operation of the reheating circuit 3 is performed, a switching control signal is output to the bath control unit 63 based on the following processing. That is, in the calorie integrating unit 641, the bath controller 6
3, one combustion burner 7 per unit time based on the control information about the opening degree setting of the gas proportional valve 75.
The current converted combustion output per unit time is obtained by multiplying the gas supply amount with respect to 1 and the number of combustion burners constituting the combustion burner group 71 currently operated for combustion. By sequentially multiplying the obtained combustion elapsed time, a current calorific value integrated value after the start of the combustion operation is obtained.

The calorific value comparison section 642 is preliminarily input and set with a calorific value set value. The calorific value comparing section 642 performs the integration of the calorific value integrated value and the calorific value setting value in parallel with the integrating process by the calorific value integrating section 641. The value is compared with the value, and the switching control signal is output to the bath control unit 63 when the integrated value of the amount of heat reaches the set value of the amount of heat.

The above-mentioned heat value is 58 to 59 kJ.
(13.8 to 14 kcal). With such a calorific value set value, the converted combustion output becomes 2
In the case of 1,000 kJ / h (5,000 kcal / h), after the combustion elapsed time of about 10 seconds, the integrated calorific value reaches the above calorific value set value, and the control signal for switching combustion to the next combustion burner group 71 is generated. Will be output.

With the above control, when the reheating circuit 3 is operated alone, the water in the bath 4 in the reheating circuit 3 is heated to perform reheating, and the reheating circuit 2 is operated.
The combustion heat is also applied to the heat exchanger 12 on the side in an averaged state over the entire length of the heat exchanger 12.
Thereby, the heat exchanger 12 and the reheating circuit 3
It is possible to avoid a situation in which both the heat exchangers 32 are locally heated, and to improve the durability of the combustion burners 71 and the like in addition to the heat exchangers 12 and 32.
In addition, it is possible to avoid a situation in which the temperature of the water in the hot water supply circuit 2, which is in a stagnant state in the heat exchanger 12, is excessively locally increased. Even if it is started, it is possible to avoid a situation in which hot water suddenly flows out of the curran 15 in a sandwich state between cold water.

<Other Embodiments> The present invention is not limited to the above-described embodiments, but includes various other embodiments. That is, in the above-described embodiment, the description has been given of a one-can, two-circuit heat exchanger using the hot water supply circuit 2 and the reheating circuit 3. However, the present invention is not limited to this. For example, the hot water supply circuit 2 and the hot water are circulated. A hot water heating circuit that heats a room may be used as a one-can-two-circuit heat exchanger.

Further, in the above embodiment, the fluid heating apparatus having a one-can, two-circuit type heat exchanger is intended. However, the present invention is not limited to this. For example, a fluid heating apparatus such as a single-function water heater or a bath kettle alone is used. , The switching control of the present invention may be applied.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an entire system of a water heater having a reheating circulation function to which an embodiment of the present invention is applied.

FIG. 2 is a partially enlarged view showing a heating can body part of FIG. 1 in an enlarged manner.

FIG. 3 is a block diagram illustrating a controller according to the embodiment with some contents omitted;

[Explanation of symbols]

2 Hot water supply circuit 3 Reheating circuit (circulation heating circuit) 12, 32 Heat exchanger 64 Switching control unit 71 Combustion burner, combustion burner group (heating source, heating source part, heating unit) 641 Heat amount integration unit 642 Heat amount comparison unit

Claims (6)

[Claims] 1. A heating control method for a fluid heating device, wherein a heating source is provided along a heat exchanger, and a heating operation of a fluid passing through the heat exchanger is performed by controlling a heating operation of the heating source. During the heating operation, the heating source is partially heated, and the heating source is heated so that the heated position at which the heat exchanger is heated is sequentially changed to a different position. A heating control method for a fluid heating device, characterized by executing a switching control for sequentially switching portions to be heated in the inside. 2. The heating control method for a fluid heating device according to claim 1, wherein the amount of heat applied to the heat exchanger from a heated portion of the heating source is integrated with time, and the amount of heat is integrated. A heating control method for a fluid heating device, wherein switching control is performed when the value reaches a predetermined heat value. 3. The heating control method for a fluid heating device according to claim 1, wherein the switching control is performed when the operation continuation time of the heated portion of the heating source reaches a predetermined operation continuation time. A heating control method for a fluid heating device to be executed. 4. The heating control method for a fluid heating device according to claim 1, wherein each of the heating sources has two or more heating units capable of independently performing a heating operation, and performs switching control from the two or more heating units. A heating control method for a fluid heating device to be selectively performed. 5. The heating control method for a fluid heating device according to claim 1, wherein the heat exchanger includes a one-can-two circuit in which a hot water supply circuit and a circulation heating circuit are respectively passed. A fluid which is a type heat exchanger, and performs a partial heating operation of a heating source and a switching control of a portion to be heated when a single heating operation of only one of the hot water supply circuit and the circulation heating circuit is performed. Heating control method for heating equipment. 6. The heating control method for a fluid heating device according to claim 5, wherein the single heating operation is a single heating operation of a circulation heating circuit.