JP7229460B2 - Heating water heater - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating and hot water supply apparatus that heats a heating medium used for room heating and supplies it to a heating terminal, and that uses this heating medium to supply hot water.

2. Description of the Related Art Conventionally, there has been used a heating and hot water supply apparatus that performs heating using a heated heating medium and heats hot water using the heat of the heating medium. For example, as disclosed in Patent Document 1, there is known a heating and hot water supply apparatus that switches between heating operation and hot water supply operation by switching the flow path of heating heat medium. Further, as disclosed in Patent Document 2, for example, there is known a heating and hot water supply apparatus configured to enable simultaneous heating and hot water supply operation in which heating operation and hot water supply operation are performed simultaneously by distributing heating heat medium.

Such a heating and hot water supply system includes a combustion section that burns fuel, a heat exchanger that exchanges heat between the high-temperature combustion gas generated in the combustion section and the heating medium, and a heating medium and hot water for hot water supply. Equipped with a hot water supply heat exchanger, etc. In the heating operation, the heating heat medium is circulated between the heat exchanger and the heating terminal. In the hot water supply operation, hot water heated by the heat exchanger for hot water supply by the heating heat medium is supplied.

Japanese Patent No. 4477566 JP 2018-59650 A

In order to supply hot water at the hot water supply set temperature, it is necessary to supply a heating heat medium having a temperature higher than the hot water supply set temperature to the hot water supply heat exchanger on the hot water supply side. Therefore, if the hot water supply operation is started during the heating operation and the temperature of the heating heat medium during the heating operation cannot supply hot water at the hot water supply set temperature, the heating heat medium is set to a temperature higher than the heating operation temperature and the hot water supply set temperature. The hot water is supplied to the hot water supply side at a higher temperature. When simultaneous heating and hot water supply operation is performed, this high-temperature heating medium is also supplied to the heating side.

At this time, the supply of high-temperature heating heat medium to the heating side may cause problems in the heating terminal and its surroundings due to the supply of heating heat medium having an excessively high temperature depending on the heating terminal. Therefore, when the temperature of the heating medium is too high, the operation is switched to the hot water supply operation without supplying the heating medium to the heating side. Therefore, in the heating and hot water supply system, the operating range in which simultaneous operation of heating and hot water supply is possible in which hot water can be supplied at the hot water set temperature is the temperature of the heating medium and the upper limit temperature of the heating medium that can be used by the heating terminal (upper limit of the heating terminal). temperature) and the set temperature of the hot water supply.

SUMMARY OF THE INVENTION An object of the present invention is to provide a heating and hot water supply apparatus capable of expanding the operating range in which simultaneous operation of heating and hot water supply is possible.

The heating and hot water supply apparatus of the invention of claim 1 comprises a combustion means, a heat exchanger for heating a heating medium with the heat generated by the combustion means, and a circulation system connecting an external heating terminal and the heat exchanger. a passage, a circulation means arranged in the circulation passage for circulating the heating heat medium, a bypass passage branched from the circulation passage and bypassing the heating terminal, and a branch portion of the bypass passage. a hot water supply heat exchanger arranged in the bypass passage; and a hot water supply passage for supplying hot water heated by the hot water supply heat exchanger at a predetermined hot water supply set temperature. wherein the distribution means is capable of adjusting a distribution ratio for distributing the heating medium to the circulation passage and the bypass passage so as to correspond to heating operation, hot water supply operation, and simultaneous heating and hot water supply operation, respectively; a branch passage branched from the outlet side passage portion of the hot water supply heat exchanger and connected to a heating forward passage portion between the distribution means and the heating terminal in the circulation passage , wherein the branch passage is An on-off valve for opening and closing is provided, and the on-off valve is opened according to the temperature of the heating medium, the upper limit temperature of the heating terminal, and the set temperature of the hot water supply during simultaneous heating and hot water supply operation.

According to the above configuration, during simultaneous heating and hot water supply operation, the heating heat medium whose temperature has been lowered by being used for heating the hot water for hot water supply in the hot water supply heat exchanger can be supplied from the branch passage to the forward passage for heating. Therefore, since the heating heat medium whose temperature has been lowered after being used for hot water supply can be used for heating, the temperature of the heating heat medium heated to a high temperature for hot water supply is lowered and supplied to the heating side, and simultaneous heating and hot water supply operation is performed. can be performed, and the operating range in which simultaneous operation of heating and hot water supply is possible can be expanded.

Then, the opening/closing valve can be opened in accordance with the temperature of the heating medium, the upper limit temperature of the heating terminal, and the hot water supply set temperature, thereby expanding the operating range in which the simultaneous heating and hot water supply operation is possible.

According to the heating and hot water supply apparatus of the present invention, it is possible to expand the operating range in which simultaneous heating and hot water supply operation is possible.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the structure of the heating hot water supply apparatus which concerns on the Example of this invention. 4 is a flow chart of transition control to simultaneous heating and hot water supply operation according to the embodiment of the present invention. 4 is a map showing an operating range in which simultaneous operation of heating and hot water supply is possible according to the embodiment of the present invention;

EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing this invention is demonstrated based on an Example.

First, the overall configuration of a heating and hot water supply apparatus 1 of the present invention will be described with reference to FIG.
The heating and hot water supply system 1 performs a heating operation in which the heating medium heated by using the combustion heat of the combustion unit 2 is circulated between the heating terminal 31 installed outside the heating and hot water supply system 1, and the heat of the heating medium is transferred. A hot water supply operation in which tap water is adjusted to a hot water supply set temperature and a simultaneous heating and hot water supply operation in which a heating operation and a hot water supply operation are performed at the same time are configured to be possible.

The heating and hot water supply system 1 includes a combustion section 2 as combustion means, a heat exchanger 10, a circulation passage 4 connecting the heat exchanger 10 and an external heating terminal 31, and an inlet of the heat exchanger 10 of the circulation passage 4. A circulation pump 11 or the like is provided on the side (upstream side) as a means for circulating heating heat medium. The combustion section 2 includes a combustion blower 3 , and the combustion section 2 combusts a mixed gas supplied by mixing supply air indicated by an arrow AS and fuel gas indicated by an arrow F by the combustion blower 3 . The amount of combustion gas and the amount of combustion heat generated are adjusted by the rotational speed of the combustion blower 3 . The heat exchanger 10 heats the heating medium to a set temperature by exchanging heat between the combustion gas generated in the combustion unit 2 and the circulating heating medium. The combustion gas, the temperature of which has been lowered by heat exchange, is discharged to the outside as indicated by an arrow E.

The heating and hot water supply apparatus 1 also includes a first bypass passage 12 (bypass passage), a hot water supply heat exchanger 20 provided in the first bypass passage 12, a water supply passage 19, a hot water supply passage 21, and the like. . The first bypass passage 12 is branched from the circulation passage 4 on the outlet side (downstream side) of the heat exchanger 10 so as to bypass the heating terminal 31, and enters the circulation passage 4 on the inlet side (upstream side) of the circulation pump 11. It is connected. The water supply passage 19 supplies tap water to the hot water supply heat exchanger 20 as indicated by an arrow CW. The hot water supply passage 21 supplies hot water heated by the hot water supply heat exchanger 20 to a hot water tap or the like as indicated by an arrow HW.

Next, the circulation passage 4 will be explained.
The circulation passage 4 has a first temperature sensor 13 between the circulation pump 11 and the heat exchanger 10 and a second temperature sensor 14 on the outlet side of the heat exchanger 10 . The first temperature sensor 13 detects the temperature of the heating medium flowing into the heat exchanger 10 . A second temperature sensor 14 detects the temperature of the heating medium heated by the heat exchanger 10 .

A first distribution valve 15 serving as distribution means for the circulating heating medium is provided at a branching portion where the first bypass passage 12 branches from the circulation passage 4 on the outlet side of the heat exchanger 10 . The first distributing valve 15 supplies the heating heat medium heated by the heat exchanger 10 to the heating forward passage portion 4a between the first distributing valve 15 and the heating terminal 31 in the circulation passage 4 and the first bypass passage 12. Distribute. The distribution ratio of the first distributing valve 15 can be adjusted, so that heating operation, hot water supply operation, and simultaneous heating and hot water supply operation can be handled. The heating heat medium distributed to the heating forward passage portion 4 a on the heating side is supplied to the heating terminal 31 , and the heating heat medium distributed to the first bypass passage 12 on the hot water supply side is supplied to the hot water supply heat exchanger 20 .

Further, the heating and hot water supply apparatus 1 includes a branch passage 32 branched from the outlet side passage portion 12a of the hot water supply heat exchanger 20 in the first bypass passage 12 and connected to the heating forward passage portion 4a. An on-off valve 33 (for example, an electromagnetic valve) for opening and closing the branch passage 32 is arranged in the branch passage 32 . The on-off valve 33 controls the temperature of the heating medium set in the simultaneous operation of heating and hot water supply (heating medium set temperature), the upper limit temperature of the heating medium that can be used in the heating terminal 31 (upper limit temperature of the heating terminal), and the hot water supply. It is opened according to the set temperature.

When the on-off valve 33 is opened, part of the heating heat medium whose temperature has been lowered by heat exchange in the hot water supply heat exchanger 20 is mixed with the heating heat medium flowing through the forward passage 4a for heating through the branch passage 32. be. Then, the heating heat medium whose temperature is lower than the set temperature of the heating heat medium due to the mixture is supplied to the heating terminal 31, and the temperature of the heating heat medium is higher than the connecting portion of the branch passage 32. It is detected by the heating outgoing temperature sensor 34 arranged in 4a. The lowering temperature α of the heating medium due to mixing is set based on a mixing experiment performed in advance by changing conditions such as the hot water supply set temperature and the hot water supply flow rate.

A pressure release valve 16 is provided between the heat exchanger 10 and the first distribution valve 15 to release the pressure in the circulation passage 4 . A heating return temperature sensor 17 for detecting the temperature of the heating medium returning from the heating terminal 31 is provided upstream of the circulation pump 11 . A replenishment passage 18 is connected between the circulation pump 11 and the heating return temperature sensor 17 as indicated by an arrow R for replenishing the heating medium.

Next, the hot water supply heat exchanger 20 will be described.
Hot water supply heat exchanger 20 is a plate heat exchanger, and passages are formed between a plurality of laminated heat exchange plates. In the hot water supply heat exchanger 20, the heat medium for heating and the clean water supplied from the water supply passage 19 flow alternately through the passages between the heat exchange plates so as to face each other without being mixed with each other. These heat exchange plates are formed with irregularities in order to increase the surface area and improve the heat exchange efficiency.

Next, the water supply passage 19 and the hot water supply passage 21 will be described.
The water supply passage 19 includes a second distribution valve 23 , a flow rate adjustment valve 24 , a hot water supply flow rate sensor 25 and an incoming water temperature sensor 26 . Tap water is supplied to the water supply passage 19 as indicated by an arrow CW when a hot water tap or the like is opened. A second bypass passage 22 is branched from the water supply passage 19, and a second distribution valve 23 disposed at this branch distributes clean water to the water supply passage 19 and the second bypass passage 22, and the distribution ratio is adjustable. be. The flow rate adjustment valve 24 adjusts the flow rate of clean water entering the second distribution valve 23 . Hot water supply flow rate sensor 25 detects the flow rate of clean water supplied to second distribution valve 23 . The incoming water temperature sensor 26 detects the temperature of clean water entering the second distributing valve 23 .

A second bypass passage 22 is connected to the hot water supply passage 21 at the junction C. As shown in FIG. An outlet hot water temperature sensor 27 is provided between the junction C and the hot water heat exchanger 20 to detect the temperature of the hot water heated by the hot water heat exchanger 20 . A hot water supply temperature sensor 28 is provided at the downstream end of the hot water supply passage 21, and the hot water for hot water supply heated by the heat exchanger 20 for hot water supply and the clean water flowing through the second bypass passage 22 are mixed and supplied. Detects hot water supply temperature. In the hot water supply operation, the second distributing valve 23 and the like are controlled so that the hot water supply temperature becomes the hot water supply set temperature.

Next, the controller 5 will be explained.
The heating and hot water supply apparatus 1 includes a control unit 5 that controls heating operation and the like. An operation terminal 6 for performing setting operations and the like of the heating and hot water supply apparatus 1 is communicably connected to the control unit 5 . This operation terminal 6 is arranged, for example, in a room where the heating terminal 31 heats the room. and a voice output unit (not shown) for outputting an alarm sound or the like. Further, an outside air temperature sensor 30 installed outdoors is connected to the control unit 5 so as to be communicable.

The control unit 5 can receive the temperature detected by the first temperature sensor 13 and the like, the rotation speeds of the combustion blower 3 and the circulation pump 11, and the like, adjust the rotation speeds of the combustion blower 3 and the circulation pump 11, and perform the first distribution. They are connected so that the distribution ratio of the valve 15 can be adjusted. Thereby, each operation of the heating operation, the hot water supply operation, and the simultaneous heating and hot water supply operation is controlled.

In addition, the control unit 5 determines whether or not simultaneous operation of heating and hot water supply is possible based on the detected temperature, set temperature of hot water supply, etc. so that heating can be performed while giving priority to hot water supply when both heating and hot water supply are requested. When it is determined that simultaneous operation of heating and hot water supply is possible, simultaneous operation of heating and hot water supply is performed, and when it is determined that simultaneous operation of heating and hot water supply is impossible, hot water supply operation is performed.

Next, the heating terminal 31 will be described.
The heating terminal 31 is a known heating device such as a floor heating device having a heat transfer tube for transferring the heat of the heating heat medium to the floor of the room, or a radiator that causes natural convection of the air warmed by the heat of the heating heat medium. . Since the upper limit temperature of the heating medium that can be used (the upper limit temperature of the heating terminal 31) may differ depending on the type of the heating terminal 31, etc., when connecting the heating terminal 31 to the heating and hot water supply system 1, 1 sets the upper limit temperature of the heating medium supplied to the heating terminal 31 . Although the upper limit temperature is set to 70° C. here, for example, it is not limited to this.

Next, the heating operation will be explained.
For example, when a heating operation start operation is performed from the operation terminal 6, the control unit 5 starts the heating operation, causes the combustion unit 2 to burn, drives the circulation pump 11, and heats the heating medium heated by the heat exchanger 10. The distribution ratio of the first distributing valve 15 is adjusted so as to flow through the heating going passage portion 4a. Then, the heating heat medium heated by the heat exchanger 10 is supplied to the heating terminal 31 , and the heating heat medium returned from the heating terminal 31 is heated by the heat exchanger 10 . The heating medium circulates between the heat exchanger 10 and the heating terminal 31 and repeats the cycle of increasing the temperature at the heat exchanger 10 and decreasing the temperature due to heat radiation at the heating terminal 31 . The temperature of the heating medium heated by the heat exchanger 10, that is, the set temperature of the heating medium, which is the target temperature after heating, is set at a temperature equal to or lower than the upper limit temperature of the heating terminal 31 according to the set room temperature of the heating, etc. Here, the temperature is set to 60° C., for example.

Next, the hot water supply operation will be explained.
When the hot water supply flow rate sensor 25 detects a flow rate equal to or higher than a predetermined value set in advance by opening a hot water supply valve or the like, the control unit 5 starts the hot water supply operation, burns the combustion unit 2, drives the circulation pump 11, and heats. In order to supply the heating medium heated by the exchanger 10 to the hot water supply heat exchanger 20 , the distribution ratio of the first distribution valve 15 is adjusted so that the heating medium flows through the first bypass passage 12 . The heating medium is heated to a temperature higher than the hot water supply set temperature by the heat exchanger 10 so as to be able to supply hot water at the hot water supply set temperature. For example, when the set hot water supply temperature is set to 40° C., the heating medium is heated to a temperature higher than the set hot water supply temperature by a predetermined temperature β (eg, β=15° C.).

The heating heat medium heated by the heat exchanger 10 exchanges heat with clean water supplied from the water supply passage 19 in the hot water supply heat exchanger 20, and then flows into the circulation passage 4 from the outlet side passage portion 12a to exchange heat. Return to vessel 10. The hot water heated by the hot water supply heat exchanger 20 is adjusted to the hot water supply set temperature in the hot water supply passage 21 and supplied to the hot water supply valve or the like. At this time, the distribution ratio of the second distributing valve 23 is adjusted based on the temperatures detected by the incoming water temperature sensor 26 and the outgoing hot water temperature sensor 27 so that the temperature detected by the hot water supply temperature sensor 28 is equal to the hot water supply set temperature. The hot water heated to a hot water supply set temperature or higher in the hot water supply passage 21 is mixed with clean water in the second bypass passage 22 and supplied to a hot water tap or the like. The distribution ratio or the like of the second distributing valve 23 may be further adjusted based on the temperature detected by the hot water supply temperature sensor 28 .

Next, simultaneous heating and hot water supply operation will be described.
In simultaneous heating and hot water supply operation, heating operation and hot water supply operation are performed simultaneously when both heating and hot water supply are requested. The heating heat medium is supplied to the heating terminal 31 and the hot water supply heat exchanger 20, respectively. Hot water supply operation is generally shorter in operation time than heating operation, and is performed each time the user uses hot water supply. Therefore, in many cases, the operation is shifted to the simultaneous heating and hot water supply operation during the heating operation, so the case of shifting from the heating operation to the simultaneous heating and hot water supply operation will be described.

When the hot water supply operation is started during the heating operation with the heating heat medium set temperature set at, for example, 60° C., and the hot water supply set temperature is, for example, 40° C., the temperature of the heating heat medium is already higher than the hot water supply set temperature by a predetermined temperature β. However, in the simultaneous heating and hot water supply operation, the heating medium is also distributed to the heating side. In this case, priority is given to hot water supply at the hot water supply set temperature, and the temperature of the heating medium is increased, and if possible, the operation is shifted to simultaneous heating and hot water supply operation.

The flow chart of FIG. 2 shows the transition control from the heating operation to the simultaneous heating and hot water supply operation. Si (i=1, 2, . . . ) in the figure represents steps. Also, FIG. 3 is a map showing the operating regions used in this transition control. In this map, the vertical axis is the heating medium set temperature and the horizontal axis is the hot water supply set temperature. It shows an operating range in which simultaneous heating and hot water supply operation is possible and an operating range in which simultaneous operation is not possible, which is determined by the set temperature. The control unit 5 has a plurality of maps created in advance based on experiments under different conditions (hot water supply flow rate and water supply temperature), and uses the maps corresponding to the conditions for simultaneous heating and hot water supply operation. The transition control will be described based on FIGS. 2 and 3. FIG.

First, in S1, based on the flow rate detected by the hot water supply flow rate sensor 25, it is determined whether hot water supply has started. If the determination is Yes, the process proceeds to S2, and if the determination is No, the process returns to S1. When the determination is Yes, it is assumed that the detected flow rate is 8 L/min and the feed water temperature is 4°C.

Next, in S2, based on the map of FIG. 3, it is determined whether hot water supply at the hot water supply set temperature is possible when shifting to simultaneous heating and hot water supply operation at the temperature of the heating medium in the current heating operation, that is, the current heating It is determined whether simultaneous heating and hot water supply operation is possible at the heat medium set temperature. FIG. 3 shows the operating regions in which the simultaneous heating and hot water supply operation is possible and in which it is impossible under the conditions of the hot water supply flow rate of 8 L/min and the water supply temperature of 4° C., as described above. A curve CL represents the relationship between the set temperature of heating medium and the maximum set temperature of hot water supply at which simultaneous operation of heating and hot water supply is possible. An operating region Z below the curve CL is a region in which simultaneous heating and hot water supply operation cannot be performed. If the determination is Yes, that is, simultaneous heating and hot water supply operation is possible at the current set temperature of heating medium, the process proceeds to S3, and if the determination is No, the process proceeds to S5.

Next, in S3, the heating and hot water simultaneous operation is started at the current set temperature of the heating medium, and the process proceeds to S4. In S4, it is determined whether the hot water supply is completed. When the hot water supply flow rate detected by the hot water supply flow rate sensor 25 is less than a predetermined value, it is determined that the hot water supply is finished. If the determination is Yes, that is, the hot water supply is finished, the process returns to the heating operation, and if the determination is No, the process returns to S4.

If the determination in S2 is No, that is, if simultaneous heating and hot water supply operation is not possible at the current heating medium set temperature, in S5, hot water supply at the hot water supply set temperature is possible based on the map of FIG. select a suitable heating medium set temperature and proceed to S6. For example, a heating heat medium set temperature of 62° C., which enables hot water supply at a maximum of 40° C., is selected, but a higher heating heat medium set temperature can also be selected.

Next, in S6, it is determined whether or not the set temperature of the heating medium selected in S5 is equal to or lower than the upper limit temperature of the heating terminal 31. If the determination is Yes, the process proceeds to S7, in which the simultaneous heating and hot water supply operation is performed using the heating medium set at the heating medium set temperature selected in S5, and the process proceeds to S10. Then, in S10, it is determined whether or not hot water supply has ended. If the hot water supply is completed and the determination is Yes, the process proceeds to S11, in which the set temperature of the heating medium is returned to the temperature before the simultaneous operation of heating and hot water supply, and returns to return to the original heating operation. If the determination is No, the process returns to S10.

On the other hand, if the set temperature of the heating medium selected in S5 exceeds the upper limit temperature of the heating terminal 31 and the determination in S6 is No, the process proceeds to S8. Then, in S8, the temperature of the heating heat medium supplied to the heating terminal 31 when the on-off valve 33 that opens and closes the branch passage 32 is opened when the simultaneous operation of heating and hot water supply is performed at the heating heat medium set temperature selected in S5 is equal to or less than the upper limit temperature of the heating terminal 31 or not. That is, it is determined whether or not the set temperature of the heating medium selected in S5 is equal to or lower than the sum of the upper limit temperature of the heating terminal 31 and the lower temperature .alpha. If the determination is Yes, the process proceeds to S9, and if the determination is No, the process proceeds to S12.

In S9, the on-off valve 33 is opened, and the simultaneous heating and hot water supply operation using the heating medium at the set temperature of the heating medium selected in S5 is started. If the hot water supply is completed and the determination is Yes, the process proceeds to S11, in which the set temperature of the heating medium is returned to the temperature before the simultaneous operation of heating and hot water supply, and returns to return to the original heating operation. If the determination is No, the process returns to S10.

If the determination in S8 is No, that is, the set temperature of the heating medium selected in S5 is too high, and even if the heating medium is mixed through the branch passage 32, the upper limit temperature of the heating terminal 31 will be exceeded. If simultaneous heating/hot water supply operation capable of supplying hot water cannot be performed, the distribution ratio of the first distribution valve 15 is adjusted in S12 to suspend the supply of the heating medium to the heating side, and the process proceeds to S13.

Next, in S13, the operation shifts to the hot water supply operation using the heating medium at the set temperature of the heating medium selected in S5, and proceeds to S14. In S14, it is determined whether or not the hot water supply has ended. When the hot water supply ends and the determination is Yes, the process proceeds to S15, in which the set temperature of the heating medium is returned to the temperature before the hot water supply operation, and returns to return to the original heating operation. If the determination is No, the process returns to S14.

The operation and effects of the heating and hot water supply apparatus 1 of the present invention will be described with reference to FIG.
For example, when the hot water supply flow rate is 8 L/min and the water supply temperature is 4° C. during the heating operation in which the heating medium set temperature is set to 60° C., the heating heat above the curve CL in FIG. The operating region X below the straight line L1 indicating the medium set temperature of 60° C. indicates the operating region in which the heating operation can be shifted to the simultaneous heating and hot water supply operation with the heating medium set temperature, and hot water supply at the hot water supply set temperature can be performed. ing. The maximum hot water supply temperature that can be supplied by simultaneous heating and hot water supply operation when the heating heat medium set temperature is 60° C. is 38° C. where the straight line L1 and the curve CL intersect, so it is possible to supply hot water at 38° C. or less.

For example, if the set temperature of the hot water supply is 40° C., the hot water supply at 40° C. cannot be supplied even if the simultaneous operation of heating and hot water supply is performed with the set temperature of the heating medium in the heating operation. To raise the maximum temperature of hot water supply setting temperature capable of supplying hot water in simultaneous operation. For example, when the upper limit temperature of the heating terminal 31 is 70°C, the set hot water supply temperature at which the straight line LH indicating the upper limit temperature and the curve CL intersect is 46°C. Therefore, if the set heating medium temperature is set to 70°C, it is possible to supply hot water at 46°C or less. You may set below the upper limit temperature of the heating terminal 31. FIG. The heating terminal 31 and the hot water supply heat exchanger 20 are each supplied with the heating medium at the heating medium set temperature.

An operating region Y′ above the curve CL and below the straight line LH indicates an operating region in which hot water supply at the set hot water supply temperature can be supplied by simultaneous heating and hot water supply operation using the heating heat medium at the upper limit temperature of the heating terminal 31 . By increasing the set temperature of the heating medium to the upper limit temperature of the heating terminal 31, the operating range of simultaneous heating and hot water supply operation is expanded from the operating range X to the operating range Y', and hot water supply at a temperature higher than the operating range X becomes possible. .

The heating and hot water supply apparatus 1 mixes the heating medium whose temperature has been lowered by opening the on-off valve 33 with the heating medium supplied to the heating terminal 31 through the branch passage 32, and supplies the heating medium to the heating terminal 31 through the branch passage 32. The temperature of the heating medium can be lowered. The drop temperature α of the heating heat medium on the heating side due to this mixture is set in advance by experiments or the like, and the set temperature of the heating heat medium is raised to a temperature higher than the upper limit temperature of the heating terminal 31 by the drop temperature α. Simultaneous hot water supply operation can be performed.

For example, when the set hot water supply temperature is 50° C., according to the map in FIG. Therefore, the temperature of the heating heat medium supplied to the heating terminal 31 is maintained below the upper limit temperature of the heating terminal 31 by opening the on-off valve 33, and the temperature of the heating heat medium supplied to the hot water supply heat exchanger 20 is reduced to the temperature of the heating terminal 31. By setting the temperature higher than the upper limit temperature, the maximum temperature of the hot water supply set temperature that can supply hot water in simultaneous heating and hot water supply operation is increased.

At this time, when the drop temperature α is, for example, 5°C, the set hot water supply temperature where the curve CL intersects the straight line L2 indicating a temperature (75°C) higher than the upper limit temperature (70°C) by the drop temperature α (5°C) is 52°C. be. Therefore, if the set heating medium temperature is set to 75°C, it is possible to supply hot water at 52°C or less. In addition, the temperature may be set to a temperature equal to or lower than the upper limit temperature plus the lowering temperature α. The hot water supply heat exchanger 20 is supplied with the heating heat medium at the heating heat medium set temperature, and the heating terminal 31 is supplied with the heating heat medium at a temperature equal to or lower than the upper limit temperature.

An operating region Y above the curve CL and below the straight line L2 indicates an operating region in which hot water supply at the hot water supply set temperature can be performed by simultaneous heating and hot water supply operation using a heating medium having a temperature higher than the upper limit temperature of the heating terminal 31 . By increasing the set temperature of the heating medium, the operating range for simultaneous operation of heating and hot water supply is expanded from the operating range Y' to the operating range Y, and the hot water supply at a temperature higher than the operating range Y' becomes possible. In addition, since the heating medium supplied to the heating terminal 31 has a temperature equal to or lower than the upper limit temperature of the heating terminal 31, it is possible to prevent problems caused by the heating medium having a temperature exceeding the upper limit temperature.

If the set temperature of hot water supply is changed to the high temperature side during simultaneous operation of heating and hot water supply, it may be determined again whether simultaneous operation of heating and hot water supply is possible in the same manner as after S2 in FIG. You may make it transfer to hot-water-supplying operation|movement without skipping. When the hot water supply set temperature is changed to the low temperature side during simultaneous operation of heating and hot water supply, it can be handled only by adjusting the distribution ratio of the second distribution valve 23, but the heating heat suitable for the hot water supply set temperature after the change can be handled. It may be set to the medium set temperature.

When the heating operation is shifted to the simultaneous heating and hot water supply operation to increase the heating heat medium set temperature, even if the heating heat medium set temperature after the increase is equal to or lower than the upper limit temperature of the heating terminal 31, the on-off valve 33 is opened. The temperature change of the heating medium supplied to the heating terminal 31 may be reduced by using the In addition, instead of the on-off valve 33, a three-way valve is disposed at the branching portion where the branch passage 32 branches from the outlet side passage portion 12a, and during simultaneous heating and hot water supply operation, the set temperature of the heating medium, the upper limit temperature of the heating terminal 31, and the hot water supply It is also possible to switch the flow path of the heating medium used for hot water supply from the outlet side passage portion 12a on the downstream side of the branch portion to the branch passage 32 according to the set temperature.

When starting heating operation during hot water supply operation, priority is given to hot water supply, so if there is sufficient heating capacity, it is sufficient to shift to simultaneous heating and hot water supply operation. may In addition, those skilled in the art can implement various modifications to the above-described embodiments without departing from the scope of the present invention, and the present invention includes such modifications.

1: Heating and hot water supply device 2: Combustion section (combustion means)
4: Circulation passage 4a: Heating forward passage 5: Control unit 10: Heat exchanger 11: Circulation pump (circulation means)
12: First bypass passage (bypass passage)
12a: outlet side passage portion 15: first distributing valve (distributing means)
19 : Water supply passage 20 : Hot water supply heat exchanger 21 : Hot water supply passage 22 : Second bypass passage 23 : Second distribution valve 25 : Hot water supply flow rate sensor 26 : Incoming water temperature sensor 31 : Heating terminal 32 : Branch passage 33 : On-off valve 34 : Temperature sensor for heating

Claims (1)

Combustion means, a heat exchanger for heating a heating medium with the heat generated by the combustion means, a circulation passage connecting an external heating terminal and the heat exchanger, and for circulating the heating medium. a circulation means arranged in the circulation passage; a bypass passage branched from the circulation passage and bypassing the heating terminal; a distribution means arranged at a branch portion of the bypass passage; and a hot water supply passage for supplying hot water heated by the hot water supply heat exchanger at a predetermined hot water supply set temperature,
The distribution means is capable of adjusting a distribution ratio for distributing the heating medium to the circulation passage and the bypass passage so as to correspond to heating operation, hot water supply operation, and simultaneous heating and hot water supply operation, respectively;
a branch passage branched from an outlet-side passage portion of the hot water supply heat exchanger in the bypass passage and connected to a heating forward passage portion between the distribution means and the heating terminal in the circulation passage ,
An on-off valve for opening and closing the branch passage is provided, and the on-off valve is opened according to the temperature of the heating medium, the upper limit temperature of the heating terminal, and the set temperature of hot water supply during simultaneous operation of heating and hot water supply. Heating water heater.

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