JPH10300195A - Combustion equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide one can two waterways type of combustion equipment by which the temperature of hot water after start of outflow of hot water can be settled within the objective temperature range, regardless of the existence of the additional stoking on bath side in stoppage of hot-water supply. SOLUTION: For this device, a second flow control valve 22 is opened in advance for mixing the supply water from a bypass path 19 by way of provision against the reopening of hot-water supply, because the temperature of hot water within the pipe 14 for hot-water supply at the section of a heat exchanger 13 reaches an extremely high temperature when there is combustion of a burner for additional stoking before the hot-water supply is reopened after stoppage of hot-water supply. On the other hand, when the burner 12 does not combust before the hot-water supply is reopened after stoppage of hot-water supply, the second flow control valve 22 is fully closed by way of provision against the next start of hot-water supply.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a one-can-two-channel combustion device for guiding a fluid flowing in a first flow path and a fluid flowing in a second flow path to one heat exchanger for heating.

[0002]

2. Description of the Related Art Some conventional combustion devices such as hot water heaters have a function of reheating a bath in addition to a function of supplying hot water. In addition, a common heat exchanger is used for a hot water supply channel and a reheating channel for a bath. There is a so-called one-can-two-channel water heater that guides and heats with a burner.

[0003] Since a common heat exchanger is used in a one-can-two-channel water heater, for example, if the bath is reheated while the hot water supply is stopped, not only the hot water in the pipe on the reheating side but also the heat exchanger The water in the pipe on the hot water supply side is also heated. For this reason, if there is reheating of the bath while hot water supply is stopped, the temperature of the hot water in the hot water supply pipe will be extremely high, and if hot water supply is started in such a state, hot water exceeding the set temperature will be discharged was there.

Therefore, in order to avoid such a situation, in a one-can-two-channel water heater, hot water from the heat exchanger is always mixed with water supplied from a bypass without passing through the heat exchanger, and burns are generated. It has been practiced to lower the tapping temperature to the extent that it does not.

In recent years, in order to further improve the comfort of the hot water heater, when the hot water is temporarily stopped and then restarted within a certain period of time, the temperature does not fluctuate greatly from the set temperature and the set temperature ± There is a demand for a water heater having a function (Q function) capable of tapping water in a temperature range of about 3 degrees.

[0006]

However, in the conventionally used one-can-two-water-channel type water heater, the temperature of the hot water is set so that the user does not get burned due to the constant mixing of the water supplied from the bypass. Mix only as much as possible. For this reason, if reheating is performed while the hot water supply is stopped, there is no burn, but there is a problem that hot water having a temperature higher than the upper limit temperature that satisfies the Q function comes out.

On the other hand, the water supply from the bypass is always mixed irrespective of the presence or absence of reheating of the bath during the stop of hot water supply. There is a problem that the falling Q function cannot be satisfied.

The present invention has been made in view of the above-mentioned problems of the prior art. The temperature of the hot water after the start of hot water supply within the target temperature range regardless of the presence or absence of reheating of the bath while the hot water supply is stopped. It is an object of the present invention to provide a one-can, two-channel type combustion device that can be stored in a single can.

[0009]

The gist of the present invention to achieve the above object lies in the following inventions. [1] A one-can-two-channel-type combustion device in which a fluid flowing through the first flow path (14) and a fluid flowing through the second flow path (15) are guided to one heat exchanger (13) and heated by a burner. (10)
In the above, the heat exchanger (1) of the first flow path (14)
3) a first flow control valve (20) provided at a location downstream of the first flow control valve (20), and a fluid at a location downstream of the first flow control valve (20); A bypass path (1) to be joined to the first flow path (14).
9), a second flow control valve (22) for adjusting the flow rate of the fluid flowing through the bypass path (19), and the heat exchange after the flow of the fluid in the first flow path (14) is stopped. Means (51) for detecting the presence or absence of combustion for heating the vessel (13), and the first flow path (14).
When the combustion for heating the heat exchanger (13) is detected by the combustion presence / absence detecting means (51) after the flow of the fluid in the first flow path is stopped, the flow of the fluid in the first flow path (14) Fluid from the first flow control valve (20) side and the second flow control valve (22)
And a valve opening initial setting means (51) for setting the opening of the first and second flow control valves (22) so as to form a state in which the fluids are mixed. Combustion device (10).

[2] The valve opening initial setting means (51)
Setting the second flow control valve (22) to a fully open state in preparation for resuming the flow of the fluid in the first flow path (14).
0).

[3] A one-can-two-channel-type combustion device for heating the fluid flowing in the first flow path (14) and the fluid flowing in the second flow path (15) with one heat exchanger (13) In (10), a first flow control valve (20) provided at a predetermined position downstream of the heat exchanger (13) in the first flow path (14), and the heat exchanger (13). ) Flows through the bypass passageway (19) where the fluid that has bypassed the above) is joined to the first flow passageway (14) at a location downstream of the first flow control valve (20), and flows through the bypass passageway (19). There is a second flow control valve (22) for adjusting the flow rate of the fluid, and combustion for heating the heat exchanger (13) after the flow of the fluid in the first flow path (14) is stopped. Combustion presence / absence detecting means (51) for detecting whether or not the first flow path (1)
When the combustion presence / absence detecting means (51) detects the combustion for heating the heat exchanger (13) after the flow of the fluid is stopped in 4), the fluid in the first flow path (14) is detected. A first valve opening initial setting means (5) for setting the first flow control valve (20) and the second flow control valve (22) to an intermediate opening, respectively, in preparation for resumption of the flow of air.
1) and after the flow of the fluid in the first flow path (14) is stopped and until the combustion for heating the heat exchanger (13) is detected by the combustion presence / absence detecting means (51). In the meantime, the first flow control valve (20) is set to an intermediate opening in preparation for the resumption of fluid flow in the first flow path (14), and the second flow control valve (22) is set. A second valve opening initial setting means (51) for setting the valve opening to a fully closed state or a predetermined minimum opening.

[4] The combustion device (10) according to any one of [1] to [3], wherein the intermediate opening degree is set once after being fully opened or fully closed.

[5] After the flow of the fluid in the first flow path (14) stops, the combustion for heating the heat exchanger (13) is detected by the combustion presence / absence detecting means (51). When the fluid from the first flow control valve (20) side is initialized by the opening of the first flow control valve (20) and the opening of the second flow control valve (22), The mixing ratio of the fluid from the second flow control valve (22) side with the temperature of the fluid before being heated by the heat exchanger (13) and the set temperature as the desired temperature of the fluid after mixing. The combustion device (10) according to [1], [2], [3], or [4], wherein the combustion device is changed according to both or one of them.

[6] Hot water is supplied through the first flow path (14), and reheating of the bath is performed through the second flow path (15). [1], [2], [3] ],
The combustion device (10) according to [4] or [5].

The present invention operates as follows. A first flow control valve (20) provided in the first flow path (14);
Adjusts the outflow of the fluid heated by the heat exchanger (13), and the second flow control valve (22) controls the fluid that has bypassed the heat exchanger (13) through the bypass passage (19). At the point downstream of the first flow control valve (20), the first
The amount to be merged into the flow path (14) is adjusted.

After the flow of the fluid in the first flow path (14) is stopped, the presence / absence detection means (51) detects the heat exchanger (1).
3) It is detected whether or not there is combustion for heating. When the combustion is detected after the flow of the fluid in the first flow path (14) is stopped, the first valve opening initial setting means (51) performs the first operation.
In preparation for the resumption of fluid flow in the flow path (14)
Of the first and second flow control valves (20, 22) such that a mixed state of the fluid from the second flow control valve (22) and the fluid from the second flow control valve (22) is formed. Set the opening.

For example, the first flow path (14) is connected to the hot water supply side,
Assuming that the second flow path (15) is on the reheating side of the bath, if there is combustion for reheating of the bath while the hot water supply is stopped, the hot water from the heat exchanger (13) is supplied to the bypass path (19). ) Is formed, and the valve opening is set to lower the tapping temperature at the start of the next hot water supply. Thus, even when reheating is performed, the tapping temperature can be reduced to an appropriate temperature immediately after the start of the next hot water supply.

Further, the water supply from the bypass passage is mixed based on whether or not combustion has occurred during the stop of the hot water supply. Therefore, compared with the case where the water supply from the bypass passage is always mixed, the reheating during the stop of the hot water supply is performed. The tapping temperature is less likely to be affected by the presence or absence, and the Q function can be satisfied by appropriately adjusting the valve opening.

In the case where the valve opening initial setting means (51) sets the second flow control valve (22) to the fully opened state in preparation for the resumption of the flow of the fluid in the first flow path (14), the bypass is not provided. Since the amount of water supplied from the path (19) increases, even if the opening of the first flow control valve (20) is increased by that amount, the tapping temperature can be kept below a predetermined upper limit temperature, The amount of hot water can be earned as a whole. further,
There is also an effect of preventing the user from feeling uncomfortable because the initial flow rate is too narrow and the flow rate is insufficient or the flow rate changes.

A first valve opening initial setting means (51)
When the combustion for heating the heat exchanger (13) is detected after the flow of the fluid in the first flow path (14) is stopped, the flow of the fluid in the first flow path (14) is detected. The first flow control valve (20) and the second flow control valve (22) are each set to an intermediate opening degree in preparation for restart. The second valve opening initial setting means (51) is configured to control the first flow control valve (20) from when the flow of the fluid in the first flow path (14) stops until combustion is detected. Is set to an intermediate opening, and the second flow control valve (22) is set to a predetermined minimum opening including closing.

For example, the first flow path (14) is connected to the hot water supply side,
Assuming that the second flow path (15) is on the reheating side of the bath, after the hot water supply is stopped, if there is no combustion for reheating, a state is formed in which the water supplied from the bypass path (19) is not mixed during that time. When the combustion is detected, a state in which the water supplied from the bypass path (19) is mixed is formed, and the state is set in a state in which the tapping water temperature is lowered.

As a result, while there is no reheating, there is no mixing of the supply water from the bypass passage (19) and the temperature of the hot water does not drop, so that the temperature of the hot water drops below the allowable range and the Q function cannot be satisfied. Occurrence can be reduced. Further, when the combustion for reheating starts while the hot water supply is stopped, the valve opening is set to a state in which the water supply from the bypass passage (19) is mixed at that time. Hot water exceeding the range can be prevented from flowing out.

Further, once the valve is set to the intermediate opening after the valve is once fully opened or fully closed, it is determined that the valve normally operates in both the opening direction and the closing direction. Can be checked at the time of initial setting. Further, by once setting the valve to the fully open or fully closed position, the intended intermediate opening can be set based on the length of time the motor for driving the valve is rotated from a reference position such as the fully open position. For example, it is possible to set an arbitrary intermediate opening degree even when a motor that can detect only the reaching of the fully closed or fully opened position by the Hall element is used.

When combustion for heating the heat exchanger (13) is detected after the flow of the fluid in the first flow path (14) is stopped, the opening of the first flow control valve (20) is determined. And the first flow rate control valve (22) is initially set by the opening degree of the second flow control valve (22).
The mixing ratio between the fluid from the side of the flow control valve (20) and the fluid from the side of the second flow control valve (22) is determined by mixing with the temperature of the fluid before being heated by the heat exchanger (13). And / or the set temperature as the desired temperature of the fluid.

For example, when the set temperature is higher than the hot water temperature in the heat exchanger (13), the first flow control valve (20) is fully opened and the second flow control valve (22) is fully closed. Set. Further, if the temperature of the fluid (water supply or the like) before being heated by the heat exchanger (13) is low, the opening of the second flow control valve (22) is reduced. ,
The degree of opening of the second flow control valve (22) is set to be large so as to increase the flow rate from the bypass path (19). By appropriately changing the mixing ratio in accordance with the set temperature, the incoming water temperature, and the like, hot water having a target temperature can be discharged immediately after the start of tapping.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. Each drawing shows an embodiment of the present invention. Water heater 10 as combustion device according to the present invention
Has a function of supplying hot water to a faucet or bath tub and a function of reheating hot water in the bath tub. As shown in FIG. 1, the water heater 10 includes a combustion chamber 11, a burner 12 is provided below the combustion chamber 11, and heat from the burner 12 is provided above the combustion chamber 11 for supplying water. The heat exchangers 13 for transmitting are arranged respectively.

The heat exchanger 13 has both a hot water supply pipe 14 for flowing hot water and a reheating circulation pipe 15 for circulating water in the bathtub for reheating.
The heat exchanger 13 has a function of transferring heat from the burner 12 to the fluid in the pipes 14 and 15 to heat the pipes.

The hot water supply pipe 14 has a check valve 16 near the water supply inlet, and a first flow sensor 17 for detecting the presence or absence of water flow and the amount of water flow slightly downstream of the check valve 16. . Further, the hot water supply pipe 14 has a fixed bypass passage 18 which is branched shortly before entering the heat exchanger 13 and joins at a position immediately after exiting the heat exchanger 13.

A first flow control valve 20 is provided downstream of the junction of the fixed bypass passage 18. The hot water supply pipe 14 is provided with a check valve 16 provided near a water supply inlet.
And a first flow sensor 17 provided on a slightly downstream side thereof.
And a bypass passage 19 that joins at a junction 21 downstream of the first flow control valve 20 without passing through the heat exchanger 13. In the middle of the bypass 19, a second flow control valve 22 for adjusting the amount of water to be bypassed is provided.

In the vicinity of the outlet of the hot water supply pipe 14, a second flow sensor 24 for detecting the presence or absence of hot water and the amount of hot water is provided. In addition, the first flow sensor 1
7, an inlet thermistor 26 for detecting the temperature of feedwater flowing through the check valve 16 is provided with a heat exchanger 13.
A heat exchange thermistor 27 for measuring the hot water temperature after heating is provided in the vicinity of the outlet of the heater.

Further, on the downstream side of the second flow sensor 24 in the hot water supply pipe 14, a tapping thermistor 28 for detecting tapping temperature is attached. The temperature of the hot water on the input side of the first flow control valve 20 is obtained by calculation based on the temperature measured by the water input thermistor 26 and the heat exchange thermistor and the bypass ratio of the fixed bypass. .

The recirculating pipe 15 for reheating includes a bath return pipe section 15a for guiding water in the bathtub to the heat exchanger 13, and a bath pipe section 15 for returning hot water heated by the heat exchanger 13 to the bathtub.
b, and a circulation pump 30 is provided in the middle of the bath return pipe section 15a. Note that the hot water supply pipe 14 and the bath return pipe portion 15a are branched from the hot water supply pipe 14 downstream from the junction 21 to form the bath return pipe portion 1a.
Pouring pipe 3 that joins 5a downstream of circulation pump 30
2, a pouring solenoid valve 33 is provided in the middle of the pouring pipe 32 to switch whether or not the hot water in the hot water supply pipe 14 flows to the bath return pipe section 15a.

The supply and exhaust are forcibly performed by blowing supply air from below the combustion chamber 11 by the combustion fan 34, and the exhaust is discharged from the upper part of the combustion chamber 11. An ignition device 35 not shown in FIG. 1 is provided near the burner 12. The combustion gas supplied to the burner 12 is supplied to the gas solenoid valve 36 and the original gas solenoid valve 3.
7. On / off control is performed by the gas switching valve 38. The amount of combustion gas supplied to the burner 12 is adjusted by a gas proportional valve 39. The gas proportional valve 39 is a valve whose flow rate changes substantially in proportion to the amount of input current.

FIG. 2 shows a circuit configuration of a control board included in the water heater 10. The control base of the water heater 10
CPU (central processing unit) that plays a central role in various controls
51 are provided. Various circuit devices are connected to the CPU 51 via various buses 52 such as a data bus and an address bus.

The ROM (Read Only Memory) 53 is a read-only memory for storing programs executed by the CPU 51 and various fixed data. R
An AM (random access memory) 54 is a working memory for storing data temporarily required for executing a program. Note that each memory may be integrated with the CPU.

The bus 52 is connected to an input / output interface circuit section 56 for inputting and outputting electric signals between the CPU 51 and various circuit devices, in addition to the main body operation section 55. The input / output interface circuit unit 56 includes the first,
Second flow sensors 17, 24, various thermistors 26 to
28, an ignition device 35, a combustion fan 34, various gas control valves 36 to 39, and first and second flow control valves 20, 2
2. The output shaft angle detection sensors 21 and 23 are connected. In addition, various control devices are connected to the input / output interface circuit unit 56 as needed.

Each of the first flow control valve 20 and the second flow control valve 22 has a motor (not shown) for driving the opening and closing of the valve. It is configured to be detected by the shaft angle detection sensors 21 and 23. Output shaft angle detection sensor 21, 2
3 can detect only whether or not the output shaft of the motor is at an angular position where the valve element is substantially fully opened and whether or not it is at an angular position where the valve element is substantially fully closed. Cannot be detected at which position. Therefore, only the three states of fully closed, fully open, and other intermediate positions can be determined from the output signal of the sensor, and the value of the intermediate opening cannot be directly known from the output signal of the sensor. However, the present invention can realize safe and comfortable control without using an expensive stepping motor.

Next, the operation will be described.

FIG. 3 shows the first flow control valve 20 and the second flow control valve 20 after the hot water supply is stopped until the hot water supply is restarted.
3 shows a valve opening degree setting state of the flow control valve 22 of FIG. The first standby state 61 includes a first flow control valve 20 and a second flow control valve in a case where combustion for reheating is performed after hot water supply is stopped and before hot water supply is restarted. 22 shows the operation and the final setting state.

The second standby state 62 indicates the operation of the first flow control valve 20 and the second flow control valve 22 and the final set state when there is no combustion for additional heating when the hot water supply is stopped. Is shown. In the first standby state 61, the first flow control valve 20 is set to an intermediate opening degree (63) after being once opened to the fully opened state. Further, the second flow control valve 22 is set to an intermediate opening (64) after it is once opened to the fully opened state.

The output shaft angle detection sensor 21 of the first flow control valve 20 and the output shaft angle detection sensor 23 of the second flow control valve 22 can detect the fully open and fully closed positions, respectively. Since the degree cannot be finely detected, the degree of opening is set to an intended degree based on the length of time of driving in the closing direction once the state is fully opened. Here, in order to set the first flow control valve 20 to the intermediate opening degree 63, the first flow control valve 20 is driven from the fully open position in the closing direction for about 5 seconds. Further, in order to set the second flow control valve 22 to the intermediate opening degree 64, the second flow control valve 22 is driven in the closing direction for about one second from the fully open position.

In the second standby state 62, the first flow control valve 20 is driven to the closing direction for about 4.5 seconds and is set to the intermediate opening degree 65 for about 4.5 seconds after it is once opened to the fully opened state. .
When the hot water supply is stopped, the second flow control valve 22 is normally in a preset minimum opening degree, and the second standby state 62
Then, the minimum opening is maintained. In this case, since the fixed bypass 18 is provided, the minimum opening is substantially fully closed. However, when the fixed bypass 18 is not provided, an appropriate minimum opening is set in order to secure a flow rate commensurate with that. You.

Since the common burner 12 and heat exchanger 13 are used in the one-can-two-channel water heater 10, if the bath is reheated while the hot water supply is stopped, the recirculating pipe 15 for reheating is used.
Not only the hot water inside but also the hot water supply pipe 1 in the heat exchanger 13
The water in 4 is also heated. For this reason, if the bath is reheated while the hot water supply is stopped, the hot water supply pipe 14 of the heat exchanger 13
The hot water inside will be at a very high temperature.

Therefore, in the first standby state 61, the first flow control valve 20 is set to an intermediate opening of about 50%, and the opening of the second flow control valve 22 is set to about 80% which is almost fully open. It is set to ~ 90%. Thus, the hot water from the first flow control valve 20 and the unheated water from the second flow control valve 22 are mixed, and the outlet temperature can be reduced to an appropriate value.

At this time, by setting the intermediate opening degree once after setting the full opening position, the intended intermediate opening degree can be set as described above, and the first flow control valve can be set. 20, the second flow control valve 22 can also be used to check whether the second flow control valve normally operates in both the opening direction and the closing direction.

If the first flow control valve 20 is fully opened and a large amount of hot water near 100 ° C. is sent out, the flow rate from the bypass passage 19 is limited. Even when fully opened, it becomes impossible to lower the tapping temperature to the target temperature. For this reason, in the first standby state 61, the first flow control valve 20 is not fully opened from the beginning, but is set to an intermediate opening.

Further, when the first flow control valve 20 is fully opened, a large amount of unheated water flows from the start of water supply on the hot water supply side until the heat exchanger 13 is ignited, and the undershoot phenomenon is likely to occur. . Therefore, the first flow control valve 20
Is not set to the fully open state from the beginning, but is set to an intermediate opening degree.

In addition, in the first standby state 61, the second
By setting the flow control valve 22 to an intermediate opening degree instead of fully opening it, the tapping temperature can be set to the target temperature in a short time. For example, when the second flow control valve 22 is set to be fully opened from the beginning, when the outlet temperature at the start of hot water supply is higher than the target temperature, the first flow control valve is used in addition to reducing the heat of the heat exchanger 13. You can only narrow down 20.

On the other hand, if the second flow control valve 22 is initially set to an intermediate opening, the first flow control valve 2
In addition to reducing the value to zero, the second flow control valve 22 can also be opened, so that the tapping temperature can reach the target temperature more quickly. This is one of the reasons why the first flow control valve 20 is not set to fully open from the beginning.

Further, when the second flow control valve 22 is fully opened from the beginning, if the elapsed time from the completion of reheating is long, hot water having a low temperature below the allowable range of the target temperature will be supplied at the start of hot water supply. May come out. However, by initially setting the second flow control valve 22 to an intermediate opening,
It can be avoided to some extent that hot water falls below the allowable range.

The opening degrees of the first flow control valve 20 and the second flow control valve 22 set in the first standby state 61 are set by the temperature of the supply water detected by the input water thermistor 26 and the main body operation unit 55. It is changed based on the set temperature etc. That is, mixing of the hot water from the first flow control valve 20 and the water from the second flow control valve 22 so that a tapping temperature corresponding to the set temperature is obtained from the temperature of the supply water and the set temperature. The ratio is set.

For example, when the set temperature is a high temperature such as 80 ° C., the second flow control valve 22 is set to a substantially fully closed state, and the first flow control valve 20 is set to a substantially fully opened state. If the target temperature is the same, the opening of the second flow control valve 22 is set to be smaller as the temperature of the supply water is lower. As described above, the mixing ratio of the hot water from the first flow control valve 20 and the water supply from the second flow control valve 22 is changed based on the temperature of the water supply and / or the set temperature. A tapping temperature close to the target temperature can be obtained immediately after the start of hot water supply.

If the set temperature is not as high as about 40 ° C., first, the second flow control valve 22 is set to the intermediate opening degree, and in this state, the first flow control valve 22 is set so that the tap water temperature becomes the target temperature.
The opening degree of the flow control valve 20 is set.

The second standby state 62 is a state set when there is no reheating during the stop of hot water supply, and the hot water temperature in the hot water supply pipe 14 at that time is not high. Therefore, in order to maintain the Q function as long as possible, the first flow control valve 20 is not fully opened but is set to an intermediate opening degree. Thus, the amount of water flowing through the hot water supply pipe 14 without being heated before the heat exchanger 13 is ignited after the start of water supply on the hot water supply side is reduced, and the occurrence of an undershoot phenomenon is suppressed to a small extent. Further, by making the second flow control valve 22 fully closed, the tapping temperature is prevented from being reduced as much as possible.

Next, the control operation of the first flow control valve 20 and the second flow control valve 22 from the stop of hot water supply to the start of hot water supply will be described.

FIG. 4 shows a flow of the control operation of the first flow control valve 20 and the second flow control valve 22 from the stop of hot water supply to the start of hot water supply. When the hot water supply is stopped (Step S201; Y), it is checked whether or not the burner 12 is burning for the reheating side (Step S2).
02). If the refueling side is burning when the hot water supply is stopped (step S202; Y), the first flow control valve 20 and the second flow control valve 22 are set to the first standby state 61 shown in FIG. (Step S203).

When the hot water supply is stopped, there is no reheating and the burner 12
Is not burning (step S202; N), the first flow control valve 20 is switched to the second standby state 62 shown in FIG.
And the second flow control valve 22 is set. After setting either the first standby state 61 or the second standby state 62,
Until the hot water supply starts again (Step S205;
N), it is monitored whether or not combustion for reheating starts (step S206).

If there is combustion for reheating before the start of hot water supply (step S206; Y), the first flow control valve 20 and the second flow control valve 22 are switched to the first flow control valve shown in FIG. The standby state 61 is set again (step S207).

According to such an operation, if the burner 12 burns even once after the hot water supply is stopped and before the hot water is restarted, the first flow control valve 2 is prepared for the next combustion.
0 and the second flow control valve 22 are set to the first standby state 61 shown in FIG. 3, and only when there is no combustion,
Are set and maintained.

FIG. 5 shows how the degree of opening of each valve changes after hot water supply is started from the first standby state. In this example, the opening degrees of the first flow control valve 20 and the second flow control valve 22 at the start of hot water supply are both set to about 50% based on the supply water temperature and the set temperature. Since the initial opening degree is determined based on the feed water temperature and the set temperature, the hot water is mixed almost at the target temperature at the start of hot water supply.

Since the temperature of the hot water from the first flow control valve 20 side gradually decreases, the opening (71) of the first flow control valve 20 gradually increases with time to maintain the target temperature. On the other hand, the opening degree of the second flow control valve 22 (7
2) gradually decreases with the passage of time, and eventually becomes fully closed. As described above, the opening of the first flow control valve 20 and the narrowing of the second flow control valve 22 are performed simultaneously in parallel, so that a transition to the steady state can be made in a short time. After the second flow control valve 22 reaches the minimum opening, the tapping temperature is controlled by the opening of the first flow control valve 20 and the amount of combustion gas supplied to the burner 12.

In the embodiment described above, in order to obtain an intended intermediate opening degree by using a motor capable of detecting only the fully open position and the fully closed position, the intermediate opening degree is set once after opening the full opening position. However, when a motor such as a stepping motor capable of finely recognizing the angle of the output shaft is used, the intermediate opening degree may be set immediately without passing through the fully open position or the like.

In the embodiment, the first standby state 61
Although the second flow control valve 22 is set to the intermediate opening as
The second flow control valve 22 may be set to the fully open state, and the adjustment for obtaining the tap water temperature at the target temperature may be performed only by the opening degree on the first flow control valve 20 side. In this case, the amount of water supplied from the bypass passage 19 becomes maximum, so that the maximum amount of hot water can be obtained within a range where the target temperature can be maintained.
However, when the second flow control valve 22 is fully opened, the degree of opening of the first flow control valve 20 increases accordingly, so that if there is a detection error or failure of the water input thermistor 26 or the heat exchange thermistor 27, etc. In this case, hot water may be discharged at a high temperature, and when importance is placed on safety, it is desirable to set the second flow control valve 22 to an intermediate opening.

Further, in the embodiment, a water heater having a bath reheating function has been described as an example. However, a combustion device having a floor heating circuit or the like instead of the reheating circuit may be used. The fluid to be heated is not limited to water, but may be ethylene glycol or the like.

[0065]

According to the combustion apparatus of the present invention, the first
When there is combustion for heating the heat exchanger after the flow of the fluid in the first flow path has stopped, the first flow control valve and the second flow control valve are prepared in preparation for the resumption of the flow of the fluid in the first flow path. Since the opening of the flow control valve is set so that the fluids from both of the flow control valves are mixed, for example, if reheating of the bath occurs during hot water supply stoppage, the flow from the heat exchanger side The hot water and the water supply from the bypass are set to be mixed,
The tapping temperature at the beginning of hot water supply restart can be reduced to an appropriate temperature.

Since the water supply from the bypass passage is mixed based on whether or not combustion has occurred during the stop of hot water supply, the water supply from the bypass passage is always compared with the case where the water supply from the bypass passage is mixed.
The tapping temperature is hardly influenced by the presence or absence of reheating during the stoppage of hot water supply, and the Q function can be satisfied by appropriately adjusting the valve opening.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a combustion device according to one embodiment of the present invention.

FIG. 2 is a block diagram showing a circuit configuration of a control board included in the combustion device according to one embodiment of the present invention.

FIG. 3 is an explanatory diagram showing a setting state of a first flow control valve and a second flow control valve during a period from a stop of hot water supply to a restart of hot water supply.

FIG. 4 is a flowchart showing a flow of a control operation of a first flow control valve and a second flow control valve from a stop of hot water supply to a start of hot water supply.

FIG. 5 is an explanatory diagram showing a change in the opening degree of each valve after the start of hot water supply when the first flow control valve and the second flow control valve are set to a first standby state.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Water heater 11 ... Combustion chamber 12 ... Burner 13 ... Heat exchanger 14 ... Hot water supply pipe 15 ... Circulation pipe for reheating 15a ... Bath return pipe part 15b ... Bath going pipe part 16 ... Check valve 17, 24 ... Flow Sensor 18: Fixed bypass path 19: Bypass path 19a ... Junction point 20 ... First flow control valve 21, 23 ... Output shaft angle detection sensor 22 ... Second flow control valve 26 ... Water input thermistor 27 ... Heat exchange thermistor 28 ... Hot water thermistor 30 Circulating pump 32 Pouring pipe 33 Pouring solenoid valve 34 Combustion fan 35 Ignition device 36 Gas solenoid valve 37 Original gas solenoid valve 38 Gas switching valve 39 Gas proportional valve 51 CPU 52 ... Bus 53 ... ROM 54 ... RAM 55 ... Main body operation unit 56 ... I / O interface circuit unit 61 ... First standby state 62 ... Second standby state

[Procedure amendment]

[Submission date] May 12, 1997

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Fig. 1

[Correction method] Change

[Correction contents]

FIG.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Kikuo Okamoto, Inventor 3-4 Fukamidai, Yamato City, Kanagawa Prefecture Inside Gaster Co., Ltd.

Claims (6)

[Claims] 1. A one-can-two-channel type combustion apparatus in which a fluid flowing through a first flow path and a fluid flowing through a second flow path are guided to one heat exchanger and heated by a burner. A first flow control valve provided at a location downstream of the heat exchanger in the path; and a first flow control valve that bypasses the heat exchanger at a location downstream of the first flow control valve. A bypass path for joining the flow path; a second flow control valve for adjusting a flow rate of the fluid flowing through the bypass path; and heating the heat exchanger after the flow of the fluid in the first flow path is stopped. Detection means for detecting whether or not there is combustion for detecting the combustion for heating the heat exchanger by the combustion detection means after the flow of the fluid in the first flow path is stopped. When the fluid flow in the first flow path is resumed. A valve that sets the opening of the first and second flow control valves so that a state in which fluid from the first flow control valve side and fluid from the second flow control valve are mixed is formed. A combustion device comprising: opening degree initial setting means. 2. The valve opening initial setting means sets the second flow control valve to a fully open state in preparation for resumption of fluid flow in the first flow path. A combustion device as described. 3. A one-tank, two-channel combustion apparatus for heating a fluid flowing through a first flow path and a fluid flowing through a second flow path with one heat exchanger, wherein A first flow control valve provided at a predetermined location downstream of the heat exchanger; and a first flow control valve for passing the fluid bypassing the heat exchanger at a location downstream of the first flow control valve. A second flow control valve for adjusting a flow rate of the fluid flowing through the bypass path; and a second flow control valve for heating the heat exchanger after the flow of the fluid in the first flow path is stopped. Combustion presence / absence detection means for detecting whether or not there is combustion, and combustion for heating the heat exchanger is detected by the combustion presence / absence detection means after the flow of the fluid in the first flow path is stopped. When the fluid flow in the first flow path is resumed. 1 of the flow control valve and the second
First valve opening initial setting means for setting each of the flow control valves to an intermediate opening degree, and after the flow of the fluid in the first flow path has stopped, the heat exchanger is detected by the combustion presence / absence detecting means. Until the combustion for heating is detected, the first flow control valve is set to an intermediate opening degree including full opening in preparation for the resumption of fluid flow in the first flow path, and And a second valve opening initial setting means for setting the second flow control valve to a fully closed state or a predetermined minimum opening. 4. The combustion apparatus according to claim 1, wherein the opening degree is set to an intermediate degree after the state is once fully opened or fully closed. 5. The first flow control valve according to claim 1, wherein when the combustion for heating the heat exchanger is detected by the combustion presence / absence detection means after the flow of the fluid in the first flow path is stopped. The fluid from the first flow control valve side, which is initially set by the opening and the opening of the second flow control valve, and the second
The mixing ratio with the fluid from the flow control valve side according to the temperature of the fluid before being heated in the heat exchanger and / or the set temperature as the desired temperature of the fluid after mixing, depending on The combustion device according to claim 1, 2, 3, or 4, wherein the combustion device is changed. 6. The hot water is supplied through the first flow path, and the hot water is supplied through the second flow path.
6. The combustion apparatus according to claim 1, wherein reheating of the bath is performed through the flow path.