JP6867933B2 - 1-can multi-circuit type hot water supply device - Google Patents

Description

The present invention relates to a one-can multi-circuit type hot water supply device having at least a hot water supply circuit and a heating circuit in one can body.

Conventionally, in this type of thing, a heat exchanger for hot water supply and a heat exchanger for bath are provided in the can body in which the heat medium for heating is stored, and heating, hot water supply, reheating of the bath and heat retention are performed respectively. It was done well. (See, for example, Patent Document 1.)

In addition, the water supply pipe is equipped with a water proportional valve that operates when the hot water supply temperature falls below the hot water supply set temperature to throttle the hot water supply flow rate, and the target control temperature for stopping the operation of this water proportional valve is set according to the hot water supply set temperature. There was something to switch. (See, for example, Patent Document 2.)

JP 2001-65884 Japanese Unexamined Patent Publication No. 2004-218973

By the way, in this conventional one, when the hot water supply operation is performed, the hot water is exchanged by the heat exchanger for hot water supply in the can, so the target temperature of the heat medium in the can is set to a high temperature of 85 ° C. and the hot water is supplied. In the heating operation, the heat medium inside the can is circulated directly to perform the heating operation, so that there is no loss of heat exchange in the heat exchanger, and the temperature of the heat medium supplied to the heater is 70 ° C. Since the heating operation alone is sufficient, the target temperature of the heat medium inside the can is set to a slightly high temperature of 70 ° C., and the heating operation alone is performed.

When the hot water tap is opened and a hot water supply request is made in that state, if the hot water supply set temperature is set to a high temperature of, for example, 45 ° C or higher, the heat exchange in the hot water supply heat exchanger cannot be completed in time, and the hot water is discharged. There is a problem that an undershoot occurs in which the temperature of the hot water supply becomes lower than the set temperature of the hot water supply.

In order to solve the above problems, in claim 1 of the present invention, the burner portion, the heating heat exchange can body in which the inner heat medium is heated by the combustion of the burner portion, and the heating heat exchange can body. A hot water supply circuit that is equipped with a heat exchanger for hot water supply inside the heat exchange can for heating and indirectly heats the water supply with the heated heat medium to supply hot water. The hot water supply circuit is provided with a water proportional valve for adjusting the amount of hot water supply, and at least when the hot water supply operation is performed by the hot water supply circuit, the target temperature inside the can is set to the first target temperature, and the heat exchange for heating is performed. When the heating operation by the heat medium in the can is independently performed, the heating operation is independently performed in the water proportional valve in the case where the target temperature in the can is set to the second target temperature lower than the first target temperature. If this is done, the operation is performed at the standby opening when the amount of hot water supplied is reduced.

Further, in claim 2, when the heating operation is performed independently and the temperature of the can body is equal to or higher than the third target temperature higher than the second target temperature and the hot water supply set temperature is equal to or lower than the predetermined temperature, water is used. The proportional valve is not operated during the standby opening when the amount of hot water supplied is reduced.

Further, in claim 3, the standby opening degree of the water proportional valve is the presence / absence of heating operation, the set hot water supply temperature, and the heat medium inside the heating heat exchange can detected by the temperature detecting means inside the can. It is determined by the temperature of.

Further, in claim 4, wherein the water proportional valve, when the water supply operation in a state of being operated to the standby opening is started, when a predetermined time has elapsed from the sheet Yuun rolling start, after the predetermined time has elapsed The opening is gradually opened.

According to claim 1 of the present invention, since the water proportional valve is operated at the standby opening degree at which the amount of hot water supplied is reduced when the heating operation is performed independently, the water proportional valve is operated in a state where the heating operation is performed independently. Even if the hot water supply operation is started, the standby opening of the water proportional valve is narrowed, so the amount of hot water supply is suppressed, so that undershoot that the hot water supply temperature becomes lower than the hot water supply set temperature can be prevented. Is.

Further, according to claim 2, when the heating operation is performed independently and the temperature of the can body is equal to or higher than the third target temperature higher than the second target temperature and the hot water supply set temperature is equal to or lower than the predetermined temperature. , Since the water proportional valve is not operated at the standby opening when the amount of hot water supply is small, the heating operation is performed independently and the target temperature of the can body is set low, and undershoot occurs even if the hot water supply operation is started in that state. It is possible to determine the case where the heating operation is not performed, and when the heating operation is performed independently, it is possible to reduce the state of narrowing the standby opening degree of the water proportional valve and reduce the deterioration of the usability of the hot water supply operation.

Further, according to claim 3, the standby opening degree of the water proportional valve is the presence / absence of heating operation, the set hot water supply set temperature, and the inside of the heating heat exchange can detected by the can body temperature detecting means. Since it is determined by the temperature of the heat medium, it is possible to always supply the maximum amount of hot water supply that can prevent undershoot that the hot water supply temperature becomes lower than the hot water supply set temperature at the start of hot water supply operation, and it is a water proportional valve. It is possible to minimize the limitation of the amount of hot water supplied at the start of the hot water supply operation by reducing the standby opening degree.

Further, according to claim 4, wherein the water proportional valve, when the water supply operation in a state of being operated to the standby opening is started, when a predetermined time has elapsed from the sheet Yuun rolling start, the predetermined time has elapsed Since the opening is gradually opened later, the can body temperature is the second can body while the standby opening of the water proportional valve is narrowed down and the heat exchange by the heat exchange for hot water supply is sufficiently performed. An undershoot occurs in which the target temperature rises from 70 ° C to the first target temperature of 85 ° C, the amount of hot water supplied increases as the temperature of the can rises, and the hot water supply temperature becomes lower than the set hot water supply temperature. It is possible to return the amount of hot water supply to the amount of hot water supply when the opening degree of the normal water proportional valve is 100% of the full opening, while preventing the hot water supply.

FIG. 6 is a schematic configuration diagram of a 1-can 3-circuit type hot water supply device according to an embodiment of the present invention. The block diagram of the main part. The flowchart of the standby opening degree control of the same water proportional valve. FIG. 5 is a flowchart of standby opening degree control of a water proportional valve according to the same other embodiment.

Next, an embodiment of the present invention will be described with reference to the drawings.
Reference numeral 1 denotes a heating can body having a combustion chamber 3 having a burning burner portion 2 at the bottom, and inside the can body 1 is for hot water supply which constitutes an indirect heating type heat exchanger for hot water supply by a serpentine tube. The heat exchange 4 and the heat exchange 5 for bath, which constitutes an indirect heating type heat exchanger using a serpentine tube, are arranged one above the other to perform hot water heating and hot water supply and bath heating can be performed simultaneously or individually. It is something like that.

First, the heating circuit A will be described. 6 is a heating going pipe, 7 is a radiator for heating such as a floor heating panel, 8 is a heating return pipe, 9 is a circulation pump for heating, 10 is a gas-liquid separator, and 11 is. An expansion tank for heating, 12 is a heating bypass pipe provided with an on-off valve 13, and 14 is a can body temperature detecting means 14 including a can body temperature sensor used for temperature control of the can body 1 for heating. The heat medium heated to the second target temperature (70 ° C. or higher) by the combustion of the burner portion 2 is sent to the heating radiator 7 by the heating circulation pump 9 via the heating going pipe 6 to heat the heating. Then, the low temperature water (about 30 ° C. to 50 ° C.) radiated by the heating radiator 7 returns to the heating can body 1 via the heating return pipe 8 and is heated to the control target temperature again and circulated.

Next, the hot water supply circuit B will be described. 15 is a water supply pipe connected to a water heater, 16 is a hot water supply flow rate sensor that detects the flow rate of water, 17 is a hot water supply pipe that discharges hot water heated by the hot water supply heat exchange 4, and 18 Is a hot water supply tap, 19 is a hot water supply bypass pipe that is connected to the hot water supply pipe 17 via a mixing valve 20 and connects the water supply pipe 15 and the hot water supply pipe 17, and 21 is a hot water supply expansion that absorbs the thermal expansion when the hot water supply tap 18 is closed. The tank, 22 is a water supply temperature sensor, 23 is a hot water supply temperature sensor, and when the hot water supply tap 18 is opened and the hot water supply flow rate sensor 16 detects the minimum operating flow rate, the temperature of the heat medium in the can body 1 is set as the first can body target. Burning is performed in the burner section 2 so as to maintain the temperature at a high temperature of about 85 ° C., and the cold water from the water supply pipe 15 is indirectly heated by the high temperature heat medium in the can body 1 in the hot water supply heat exchange 4, and the mixing valve 20 The hot water is supplied from the hot water tap 18 after being mixed with tap water and adjusted to an appropriate temperature. The water supply pipe 15 is provided with a water proportional valve 24 for reducing the amount of hot water supplied when the capacity is exceeded.
The water proportional valve 24 may be provided in the hot water supply pipe 17.

Next, the bath circuit C will be described. 25 is a bath tub, 26 is a bath going pipe, 27 is a bath return pipe, 28 is a bath circulation pump provided in the return pipe 29, and 29 is a running water switch for detecting the presence or absence of circulation. Reference numeral 30 denotes a bath temperature sensor, and when there is a request to boil water in the bath 25, the burner unit keeps the temperature of the heat medium in the can body 1 at a high temperature of about 85 ° C., which is the target temperature of the first can body 1. Burning is performed in 2, the hot water in the bath 25 is circulated to the heat exchange 5 for the bath by the bath circulation pump 28, and the hot water in the bath is indirectly heated by the high temperature heat medium in the heating can body 1, so that the bath is heated. The hot water in 25 is boiled to an appropriate temperature or kept warm.

Reference numeral 31 denotes a hot water filling pipe that is branched from the hot water supply pipe 17 of the hot water supply circuit B and connected to the bath circuit C via the hot water filling valve 32 and the three-way valve 33. The bath circuit C and the hot water filling pipe 31 are switched to communicate with each other, the hot water filling valve 32 is opened, and the hot water heated by the hot water supply heat exchange 4 flows into the bath circuit C to a certain amount to the bath tub 28. It is for filling the water.

Here, 34 is a communication pipe connecting the upper and lower parts of the heating can body 1, and 35 is a circulation pump for stirring provided in the middle of the communication pipe 34, which is driven during hot water supply or bath operation to drive the heating can body 1. The temperature inside is made uniform up and down, and it is continuously driven and stirred until the hot water supply or bath operation is completed. Since the heating circulation pump 9 is driven during the heating operation, it is possible to prevent the stirring circulation pump 35 from being driven.

Reference numeral 36 denotes a control unit composed of a microcomputer, which has a hot water supply temperature sensor 23 on the input side, a hot water supply temperature setting means 37 for appropriately setting the hot water supply temperature to a desired temperature, and a hot water supply temperature setting means 37 for appropriately setting the temperature of the bath water. Bath temperature setting means 38, bath reheating operation switch 39 for heating bath water to the temperature set by the bath temperature setting means 38, heating switch 40 for starting and stopping heating operation, hot water supply flow rate sensor 16, water supply temperature. The sensor 22, the can body temperature detecting means 14, the running water switch 29, and the bath temperature sensor 30 are connected to each other, and the burner portion 2, the mixing valve 20, the water proportional valve 24, the heating circulation pump 9, and the on-off valve 13 are connected to the output side. , Bath circulation pump 28, hot water filling valve 32, three-way valve 33, stirring circulation pump 35, timer 41 for counting time are connected respectively, heating operation, hot water supply operation, bath hot water filling operation and reheating operation, It controls the combustion of the burner unit 2.

Next, the operation of this embodiment will be described.
First, to explain the heating operation, when the heating operation is started, the can body temperature detecting means 14 detects the temperature inside the heating can body 1, and the can body temperature is 75 ° C., which is the third target temperature of the can body. When the above is reached, the combustion of the burner portion 2 is stopped, and when the temperature inside the can becomes 65 ° C. or less, which is the fourth target temperature of the can body, the combustion of the burner portion 2 is started so that the temperature inside the can becomes about 70 ° C. In addition to controlling the combustion of the burner unit 2, the heating circulation pump 9 is driven to distribute hot water, circulating fluid, antifreeze, or other heat medium that has become hot in the heating can body 1 to the heating radiator 7. The room is heated by the heating radiator 7 by repeating the circulation of returning to the heating can body 1 again.

Next, in the hot water supply operation, when the hot water supply plug 18 is opened and the hot water supply operation is started, the can body temperature detecting means 14 detects the temperature inside the heating can body 1, and the burner is set so that this temperature becomes about 85 ° C. While controlling the combustion of the part 2, the low-temperature water from the water supply pipe 15 is indirectly heated by the high-temperature heat medium in the heating can body 1 by the hot water supply heat exchanger 4, and at the same time, the stirring circulation pump 35 is used. The hot water in the lower part of the heating can body 1 is supplied to the upper part of the heating can body 1 via the communication pipe 34 to stir the heating can body 1, and the temperature difference between the upper part and the lower part in the heating can body 1 is performed. The hot water at a desired temperature is supplied so that heat exchange can always be performed with the same heat exchange efficiency.

Next, in bath operation, when there is a request to boil water in the bath 26 such as turning on the bath heat retention switch of a remote control (not shown), the circulation pump 29 for bath is driven to exchange heat in the bath 26 for heat. It is circulated in the vessel 5 and heated by the heat medium in the heating can body 1 held at a high temperature to reheat or keep the hot water in the bath 26 at a desired temperature. The bath temperature sensor 31 Is automatically stopped when it detects a desired temperature.

Next, the control of the standby opening degree of the water proportional valve 24 before the hot water supply operation is started will be described with reference to the flowchart shown in FIG.
First, it is determined whether only the heating operation is being operated, that is, whether the heating operation is being carried out independently (S1), and when the heating operation is not being carried out independently, that is, when all the operations are not being carried out. At least when hot water supply operation or bath reheating operation is performed, the target temperature of the can body is set to 85 ° C., which is the first target temperature of the high temperature (S2), and the standby opening degree of the water proportional valve 24 is set. It is set to 100% in the fully opened state and returns to (S3) and (S1).

Further, when it is determined in (S1) that the heating operation is performed independently, the can body target temperature is set to 70 ° C., which is the second can body target temperature lower than the first can body target temperature of 85 ° C. Set. (S4)
Next, it is determined whether the can body temperature detected by the can body temperature detecting means 14 is 75 ° C. or higher, which is higher than the second can body target temperature (S5), and if the can body temperature is 75 ° C. or higher, heating is performed. It is determined that the can body 1 has a sufficient amount of heat.
Here, in (S5), it is determined whether the can body temperature is 75 ° C. or higher, which is higher than the second can body target temperature, by burning the burner portion 2 when the second can body target temperature is 70 ° C. Even if the can body temperature rises to the third can body target temperature of 75 ° C. and the combustion of the burner portion 2 is stopped, the can body temperature subsequently rises to 75 ° C. or higher, causing an overshoot, so that the can body temperature rises. Whether it is 75 ° C. or higher is determined by (S5).

Next, it is determined whether the hot water supply temperature set by the hot water supply temperature setting means 37 is 45 ° C. or higher, which is a high temperature for hot water supply (S6). The heat of the heat medium in the heating can body 1 is exchanged at once by the hot water supply heat exchange 4, and the hot water supply is started to set the can body target temperature from 70 ° C., which is the second can body target temperature, to the first can body target. Even if the temperature is changed to 85 ° C., it is judged that there is a possibility of undershooting due to insufficient heating of hot water in the hot water supply heat exchange 4, and the water proportional valve 24 is operated in the closing direction to stand by. The degree is set to 75%. (S7)

Further, when the hot water supply set temperature set in (S6) is less than 45 ° C., the heat of the heat medium in the heating can body 1 is used for hot water supply when the hot water supply is started as compared with the case where the hot water supply set temperature is 45 ° C. or higher. There is little heat exchange due to heat exchange 4, and if hot water supply is started and the target temperature of the can body is changed from 70 ° C, which is the target temperature of the second can body, to 85 ° C, which is the target temperature of the first can body, it is for hot water supply. It is determined that the hot water can be sufficiently heated by the heat exchange 4 and there is no possibility of undershooting, and the standby opening degree of the water proportional valve 24 is set to 100% of the fully opened state. (S8)

As a result, even when it is determined that the heating operation is performed independently and the target temperature of the can body is set to 70 ° C., which is the second target temperature of the can body, which is lower than the target temperature of 85 ° C. of the first can body. If the can body temperature at that time is high and the hot water supply set temperature is low, an undershoot occurs in which the hot water supply temperature becomes lower than the hot water supply set temperature even if the hot water supply operation is started while the heating operation is performed independently. Since it is judged that there is no possibility of this, the standby opening of the water proportional valve 24 is set to 100% of the fully open state, so that the heating operation is independently performed and the target temperature of the can body is set low, and hot water is supplied in that state. It is possible to determine when the undershoot does not occur even when the operation is started, and when the heating operation is performed independently, it is possible to reduce the state of narrowing the standby opening degree of the water proportional valve 24 and reduce the deterioration of usability. ..

Further, when the can body temperature detected by the can body temperature detecting means 14 in (S5) is less than 75 ° C., which is higher than the second can body target temperature, there is not a sufficient amount of heat in the heating can body 1. Then, it is determined whether the hot water supply set temperature set by the hot water supply temperature setting means 37 is 45 ° C. or higher, which is a high temperature for hot water supply (S9). When the hot water supply is started, the heat of the heat medium in the heating can body 1 is exchanged at once by the hot water supply heat exchange 4, and the hot water supply is started to set the can body target temperature from the second can body target temperature of 70 ° C. to the first. Even if the target temperature of the can body is changed to 85 ° C, it is judged that the possibility of undershooting due to insufficient heating of hot water in the hot water supply heat exchange 4 is higher than when the can body temperature is 75 ° C or higher. The water proportional valve 24 is operated in the closing direction to set the standby opening degree to 70%, which is narrower than when the can body temperature is 75 ° C. or higher. (S10)

Further, when the hot water supply set temperature set in (S9) is less than 45 ° C., the heat of the heat medium in the heating can body 1 is used for hot water supply when the hot water supply is started as compared with the case where the hot water supply set temperature is 45 ° C. or higher. Although heat is rarely exchanged by the heat exchange 4, it is determined that the heating can body 1 does not have a sufficient amount of heat when the can body temperature is lower than 75 ° C., which is higher than the second can body target temperature, and hot water supply is started. Even if the target temperature of the can body is changed from 70 ° C, which is the target temperature of the second can body, to 85 ° C, which is the target temperature of the first can body, it is insufficient to heat the hot water by the heat exchange 4 for hot water supply. It is determined that there is a possibility of shooting, and the water proportional valve 24 is operated in the closing direction to set the standby opening degree to 75%. (S11)

Then, after determining the standby opening degree of the water proportional valve 24 in (S7), (S8), (S10), and (S11) and operating the water proportional valve 24, it is detected whether the hot water supply plug 18 is opened and the hot water supply operation is started. If the hot water supply operation is not started, the process returns to (S1), and if the hot water supply operation is started, the target temperature of the can body is changed from 70 ° C., which is the second target temperature of the can body, to 85 ° C., which is the target temperature of the first can body. After setting (S13), the timer 41 is operated to start counting. (S14)

Then, in (S14), it is determined whether the time counting time of the timer 41 has passed a predetermined time, and in this embodiment, 30 seconds have passed (S15), and in (S15), when the measuring time of the timer 41 has passed 30 seconds, 10 thereafter. Every second, the opening degree of the water proportional valve 24 is opened by 5% (S16), then it is determined whether the opening degree of the water proportional valve 24 is 100% or more (S17), and the opening degree of the water proportional valve 24 is increased. When it reaches 100% or more, it returns to (S1), and when the opening degree of the water proportional valve 24 does not reach 100% or more, it is confirmed whether the hot water supply operation is stopped (S18), and the hot water supply operation is stopped. If it is done, it returns to (S1), and if the hot water supply operation is not stopped, it returns to (S16).

As described above, when the heating operation is performed independently, the standby opening of the water proportional valve 24 of the hot water supply circuit is narrowed down, so that even if the hot water supply operation is started while the heating operation is performed independently, water is used. Since the standby opening degree of the proportional valve 24 is narrowed down, the amount of hot water supplied is suppressed, so that it is possible to prevent undershoot in which the hot water supply temperature becomes lower than the hot water supply set temperature.

That is, since the target temperature of the can body when the heating operation is independently performed is set to a temperature as low as 70 ° C. with respect to the target temperature of the can body of 85 ° C. at other times, the heating operation is independently performed. In this case, fuel can be saved, and when the hot water supply operation is started while the heating operation is performed independently, if the standby opening of the water proportional valve 24 is 100% of the fully open, heat exchange in the hot water supply heat exchange 4 is performed. Undershoot occurs in which the hot water supply temperature becomes lower than the hot water supply set temperature in time, but when the bunch operation is performed independently, by narrowing the standby opening of the water proportional valve 24, heat exchange for hot water supply It is possible to prevent the occurrence of undershoot in which the heat exchange in No. 4 can be sufficiently performed and the hot water supply temperature becomes lower than the hot water supply set temperature.

Further, since the opening degree of the water proportional valve 24 is gradually opened after a predetermined time has elapsed from the start of the hot water supply operation in the state where the heating operation is independently performed, the opening degree of the water proportional valve 24 is fully opened. By opening the opening of the water proportional valve 24 by a predetermined angle at regular time intervals, the standby opening of the water proportional valve 24 is narrowed down and the heat exchange in the hot water supply heat exchange 4 is sufficiently performed. In the meantime, the can body temperature rises from the second can body target temperature of 70 ° C. to the first can body target temperature of 85 ° C., and the amount of hot water supplied increases as the can body temperature rises, and the hot water supply temperature rises. While preventing the occurrence of undershoot that becomes lower than the set temperature for hot water supply, the amount of hot water supply can be returned to the amount of hot water supply when the opening degree of the normal water proportional valve 24 is 100% of the fully open position.

Next, another embodiment of controlling the standby opening degree of the water proportional valve 24 before the hot water supply operation is started will be described with reference to the flowchart shown in FIG.
The same steps as in the flowchart of FIG. 3 have the same number, and the description of the same steps will be omitted.

The control of the standby opening degree of the water proportional valve 24 before the start of the hot water supply operation in the flowchart of FIG. 3 is different from the control of narrowing the standby opening degree of the water proportional valve 24 when the heating operation is independently performed. The control of the standby opening degree of the water proportional valve 24 before the start of the hot water supply operation in the flowchart of FIG. 4 is a control for narrowing the standby opening degree of the water proportional valve 24 even when the heating operation is not performed independently. Is.

First, it is determined whether only the heating operation is being operated, that is, whether the heating operation is being carried out independently (S1), and when the heating operation is not being carried out independently, that is, when all the operations are not being carried out. At least when hot water supply operation or bath reheating operation is performed, the can body target temperature is set to 85 ° C., which is the first high temperature target can body temperature (S2), and then whether the hot water supply operation is performed or not. judge. (S19)

Then, when it is determined in (S19) that the hot water supply operation is being carried out, the opening degree of the water proportional valve 24 is set to 100% of the fully open position (S20), and the process returns to (S1).
Further, when it is determined in (S19) that the hot water supply operation is not performed, it is determined whether the can body temperature detected by the can body temperature sensor 14 is 75 ° C. or higher, which is higher than the second can body target temperature. (S21) When the can body temperature is 75 ° C. or higher, it is determined that the heating can body 1 has a sufficient amount of heat.

Next, it is determined whether the hot water supply temperature set by the hot water supply temperature setting means 37 is 45 ° C. or higher, which is a high temperature for hot water supply (S22). If the first target temperature of the can body is 85 ° C., even if the hot water supply operation is started, the hot water can be sufficiently heated by the hot water supply heat exchange 4, and there is no possibility of undershooting, but the target temperature of the can body is high. Even if the target temperature of the can body of 1 is 85 ° C., the temperature of the can body is between 75 ° C., which is the temperature at which it is judged that the heating can body 1 has sufficient heat, and 85 ° C., which is the target temperature of the first can body. When the temperature was high, it was judged that there was some possibility of undershooting due to insufficient heating of the hot water in the hot water supply heat exchange 4, and the water proportional valve 24 was operated in the direction of slightly closing to open the standby position. Is set to 90%. (S23)

Further, when the hot water supply temperature set in (S22) is less than 45 ° C., the heat of the heat medium in the heating can body 1 becomes the heat for hot water supply due to the start of hot water supply as compared with the case where the hot water supply set temperature is 45 ° C. or higher. Heat is rarely exchanged by crossing 4, and the target temperature of the can body is 85 ° C, which is the first target temperature of the can body. Therefore, even if the hot water supply operation is started, the hot water can be sufficiently heated by the hot water supply heat exchange 4, and the undershoot can be performed. It is determined that there is no possibility of this, and the standby opening degree of the water proportional valve 24 is set to 100% of the fully opened state. (S24)

Further, when the can body temperature detected by the can body temperature sensor 14 in (S21) is less than 75 ° C., which is higher than the second target temperature of the can body, it is determined that there is not a sufficient amount of heat in the heating can body 1. Next, it is determined whether the hot water supply temperature set by the hot water supply temperature setting means 37 is 45 ° C. or higher, which is high in hot water supply (S25), and if the set hot water supply temperature is 45 ° C. or higher, the hot water supply is started. The heat of the heat medium in the heating can body 1 is exchanged at once by the hot water supply heat exchange 4, and even if the can body target temperature is 85 ° C., which is the first can body target temperature, hot water is hot water supplied by the hot water supply heat exchange 4. It is determined that there is a possibility of undershooting due to insufficient heating, and the water proportional valve 24 is operated in the closing direction to set the standby opening degree to 80%. (S26)

Further, when the hot water supply temperature set in (S25) is less than 45 ° C., the heat of the heat medium in the heating can body 1 becomes the heat for hot water supply due to the start of hot water supply as compared with the case where the hot water supply set temperature is 45 ° C. or higher. Although heat is rarely exchanged by crossing 4, it is judged that there is not enough heat in the heating can body 1 when the can body temperature is lower than 75 ° C., which is higher than the second can body target temperature, and the can body target temperature. However, even if the target temperature of the first can body is 85 ° C., it is judged that there is some possibility of undershooting due to insufficient heating of hot water in the heat exchange 4 for hot water supply, and the water proportional valve 24 is slightly set. It is operated in the closing direction to set the standby opening degree to 90%. (S27)

Then, after determining the standby opening degree of the water proportional valve 24 in (S23), (S24), (S26), and (S27) and operating the water proportional valve 24, it is detected whether the hot water supply plug 18 is opened and the hot water supply operation is started. If the hot water supply operation is not started, the process returns to (S1), and if the hot water supply operation is started, the target temperature of the can body is set to 85 ° C., which is the first target temperature of the can body (S13), and then (S14). It goes to.

As described above, when the heating operation is carried out independently, the standby opening degree of the water proportional valve 24 of the hot water supply circuit is greatly reduced, so that even if the hot water supply operation is started while the heating operation is carried out independently. Since the standby opening degree of the water proportional valve 24 is narrowed down, the amount of hot water supplied is suppressed, so that it is possible to prevent undershoot in which the hot water supply temperature becomes lower than the hot water supply set temperature.

That is, since the target temperature of the can body when the heating operation is independently performed is set to a temperature as low as 70 ° C. with respect to the target temperature of the can body of 85 ° C. at other times, the heating operation is independently performed. In this case, fuel can be saved, and when the hot water supply operation is started while the heating operation is performed independently, if the standby opening of the water proportional valve 24 is 100% of the fully open, heat exchange in the hot water supply heat exchange 4 is performed. Undershoot occurs in which the hot water supply temperature becomes lower than the hot water supply set temperature in time, but when the bunch operation is performed independently, by narrowing the standby opening of the water proportional valve 24, heat exchange for hot water supply It is possible to prevent the occurrence of undershoot in which the heat exchange in No. 4 can be sufficiently performed and the hot water supply temperature becomes lower than the hot water supply set temperature.

Further, when the heating operation is not performed independently, the standby opening of the water proportional valve 24 of the hot water supply circuit is narrowed down to a small size, so that the hot water supply is set even when the target temperature of the can body is high at 85 ° C. If there is a possibility that an undershoot may occur in which the hot water supply temperature becomes lower than the hot water supply set temperature due to the set temperature and the detected can body temperature, the standby opening of the water proportional valve 24 should be narrowed down to make the hot water supply. The amount is made smaller than the amount of hot water supplied when the opening of the normal water proportional valve 24 is 100% when it is fully opened, and even if the heating operation is not performed independently, the hot water supply temperature becomes lower than the hot water supply set temperature at the start of the hot water supply operation. It is possible to prevent the occurrence of undershoot.

The standby opening degree of the water proportional valve 24 depends on the presence or absence of heating operation, the set hot water supply set temperature, and the temperature of the heat medium inside the heating heat exchange can detected by the can body temperature detecting means 14. Since it is determined, the maximum amount of hot water supply that can prevent undershoot that the hot water supply temperature becomes lower than the hot water supply set temperature at the start of hot water supply operation can always be supplied, and the standby opening degree of the water proportional valve 24 can be supplied. It is possible to minimize the limit on the amount of hot water supplied at the start of hot water supply operation by squeezing.

1 Heat exchange can body for heating 2 Burner part 4 Heat exchange for hot water supply 14 Can body temperature detecting means 24 Water proportional valve A Heating circuit B Hot water supply circuit

Claims (4)

A burner portion, a heating heat exchange can body in which an inner heat medium is heated by combustion of the burner portion, a can body temperature detecting means for detecting the temperature of the heat medium inside the heating heat exchange can, and the above. A heat exchanger for hot water supply is provided inside the heat exchange can for heating, and a hot water supply circuit that indirectly heats the water supply with the heated heat medium to supply hot water is provided. The hot water supply circuit is equipped with a water proportional valve that adjusts the amount of hot water supply. If at least the hot water supply operation by the hot water supply circuit is performed, the target temperature inside the can is set to the first target temperature, and if the heating operation by the heat medium inside the heat exchange can for heating is performed independently, the can. In setting the internal target temperature to a second target temperature lower than the first target temperature, the water proportional valve operates at a standby opening degree in which the amount of hot water supplied is reduced when the heating operation is performed independently. A one-can multi-circuit hot water supply device that is characterized by being kept. When the heating operation is performed independently and the temperature of the can body is higher than the second target temperature and is equal to or higher than the third target temperature and the hot water supply set temperature is equal to or lower than the predetermined temperature, the water proportional valve has a small amount of hot water supply. The one-can multi-circuit type hot water supply device according to claim 1, wherein the water heater is not operated at the standby opening degree. The standby opening degree of the water proportional valve is determined by the presence or absence of heating operation, the set hot water supply set temperature, and the temperature of the heat medium inside the heating heat exchange can detected by the temperature detecting means inside the can. The one-can multi-circuit type hot water supply device according to claim 1. The water proportional valve when the water supply operation is started in a state of being operated to the standby opening, to open progressively the opening from the sheet Yuun rolling starts after a predetermined time has elapsed Once the predetermined time has elapsed The one-can multi-circuit type hot water supply device according to any one of claims 1 to 3, wherein the water heater is characterized by the above.

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