JP2021032487A - Hot water supply device - Google Patents

Abstract

To properly control a hot water supply temperature to a bathtub in a hot water supply operation to the bathtub in a case where an inflow water temperature is high, in the hot water supply device including a main heat source for hot water supply and an auxiliary heat source for reheating.SOLUTION: In a hot water supply device 100a, hot water output from a hot water supply pipe 13a to a reheating circulation passage 8 is divided into a first passage from a connection point 8c to a bathtub 20 through a heat exchanger 4c and a second passage from the connection point 8c to the bathtub 20 without passing through the heat exchanger 4c, by opening a hot water supply valve 13 in a state of stopping a reheating circulation pump 10 in a hot water supply operation to the bathtub 20. The hot water supply operation has a low heating mode for stopping an operation of a burner 2a as a main heat source and heating a part of the hot water circulated in the first passage by the heat exchanger 4c by using output heat of a burner 2b as an auxiliary heat source.SELECTED DRAWING: Figure 1

Description

The present invention relates to a hot water supply device, and more specifically, to a hot water supply device that includes a bathtub at a hot water supply destination and has a function of reheating bath water.

In a hot water supply device that is equipped with both a heat exchanger for hot water supply and a heat exchanger for reheating and includes a bathtub at the hot water supply destination, the bath water usually passes through the heat exchanger for reheating when the reheating circulation pump is operated. The reheating operation is executed by forming a circulation path through which the water flows. Further, during the hot water pouring operation into the bathtub, the hot water pouring solenoid valve is opened to form a hot water pouring route from the hot water supply pipe connected to the downstream side of the hot water supply heat exchanger to the bathtub side.

Since the reheating circulation pump is stopped during the hot water pouring operation of the hot water supply device, the hot water introduced into the hot water pouring path is divided into a path through which the reheating heat exchanger passes and a path through which it does not flow. It is common to reach the bathtub. Japanese Patent Application Laid-Open No. 2004-444878 (Patent Document 1) and Japanese Patent Application Laid-Open No. 2001-214549 (Patent Document 2) describe a heat exchanger for hot water supply and a heat exchanger for reheating during hot water pouring operation into a bathtub. It is described that heating is performed in both of the above.

In Patent Document 1, by providing a check valve on the reheating circulation path, the entire amount of hot water supplied from the hot water supply heat exchanger is reheated even during the hot water injection operation in which the reheating circulation pump is stopped. The configuration for passing through the exchanger is described. Further, Patent Document 2 describes that the amount of heating in the reheating heat exchanger is controlled according to the temperature at which the hot water is poured into the bathtub during the hot water pouring operation into the bathtub.

Japanese Unexamined Patent Publication No. 2004-444878 Japanese Unexamined Patent Publication No. 2001-215049

When preheated hot water from a solar hot water utilization device or a fuel cell unit or the like enters the hot water supply device, the temperature of the water entering the hot water supply device may be close to the set temperature of the bath. On the other hand, there is a limit to reducing the amount of heating in the water heater. In particular, in a configuration in which heating is performed in a heat exchanger by burning fuel such as gas, there is a controllable lower limit of the amount of heating in order to ensure combustion stability.

The present invention has been made to solve such a problem, and an object of the present invention is a case where the water inlet temperature is high in a hot water supply device provided with a main heat source for hot water supply and an auxiliary heat source for reheating. In the operation of pouring water into the bathtub, the temperature of pouring water into the bathtub is appropriately controlled.

In a certain aspect of the present invention, a hot water supply device including a hot water supply destination includes a main heat source for hot water supply, first and second heat exchangers, a first circulation path, a hot water pouring pipe, and a bath pouring hot water. It includes a valve, a flow detector, an auxiliary heat source, and a controller. The first heat exchanger heats the incoming water according to the amount of heat from the main heat source and outputs it to the hot water supply pipe. The first circulation path is a circulation path for bathtub water that is communicated with the bathtub. The hot water pouring pipe is arranged between the hot water supply pipe and the first circulation path. The bath pouring valve and the flow rate detector are provided in the pouring pipe. The auxiliary heat source is used for heating hot water flowing through the first circulation path. The first circulation path has a connection point with a second heat exchanger, a circulation pump, first and second pipes, and a hot water pouring pipe. The second heat exchanger heats the hot water flowing through the first circulation path by using the amount of heat from the auxiliary heat source. The circulation pump is arranged to circulate the bath water in the first circulation path. The first pipe connects the bathtub to one end of the second heat exchanger. The second pipe connects the bathtub to one end of the second heat exchanger. The connection point is provided in the second pipe. The controller controls the main heat source, the auxiliary heat source, the bath pouring valve, and the circulation pump. The controller stops the operation of the main heat source and uses the output heat amount of the auxiliary heat source by the second heat exchanger in the hot water pouring operation to the bathtub that opens the bath pouring valve with the circulation pump stopped. It has a low heating mode that heats a part of hot water flowing through the first circulation path.

According to the present invention, in a hot water supply device provided with a main heat source for hot water supply and an auxiliary heat source for reheating, in a hot water pouring operation into a bathtub when the water entry temperature is high, the combustion of the main heat source is stopped and the auxiliary heat source is used. By applying the low heating mode that heats the hot water flowing through the first path, the pouring temperature into the bathtub can be appropriately controlled.

It is a schematic diagram which shows the structure of the hot water supply system including the hot water supply apparatus which concerns on embodiment of this invention. It is a conceptual diagram explaining the state of the circulation path for reheating at the time of a hot water pouring operation. It is a flowchart explaining the control process of the bath water filling operation including the hot water pouring operation of the low heating mode by the hot water supply device which concerns on this embodiment. It is a flowchart explaining the detail of the temperature control of the low heating mode shown in FIG. It is a conceptual diagram which shows the 1st example of the heating amount control by the auxiliary heat source shown in FIG. It is a conceptual diagram which shows the 2nd example of the heating amount control by the auxiliary heat source shown in FIG. It is a conceptual diagram explaining an example of opening degree control of the flow rate control valve shown in FIG. It is the schematic explaining the modification of the structure of the hot water supply device which concerns on embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following, the same or corresponding parts in the figure are designated by the same reference numerals, and the explanations will not be repeated in principle.

FIG. 1 is a schematic view showing a configuration of a hot water supply system including a hot water supply device according to an embodiment of the present invention.

With reference to FIG. 1, the hot water supply system 300a includes a hot water supply device 100a. The hot water supply device 100a includes a bathtub 20 installed in the bathroom 200 as a hot water supply destination in addition to a hot water tap or the like (not shown).

The hot water supply device 100a includes a housing 1, a burner 2, a fan 3, a heat exchanger 4, a water inlet pipe 5, a hot water supply pipe 6, a bypass valve 7, a bypass pipe 7a, a reheating circulation path 8, and temperature sensors 9a, 9b, 18 , 19, a reheating circulation pump 10, a water level sensor 11, a controller 12, a bath water pouring valve 13, and remote controls 30 and 50.

The housing 1 is provided so that the inside and the outside of the housing 1 communicate with each other, and has an exhaust port 1a for exhausting combustion gas. The housing 1 has at least a burner 2, a fan 3, a heat exchanger 4, a water inlet pipe 5, a hot water supply pipe 6, a bypass valve 7, a bypass pipe 7a, a reheating circulation pump 10, a water level sensor 11, a controller 12, and a bath. It is configured to accommodate the pouring valve 13. Further, the housing 1 accommodates a part of the reheating circulation path 8.

The burner 2 is configured to perform a combustion operation by receiving a fuel gas supply from a fuel supply system (not shown). The burner 2 supplies the combustion gas to the heat exchanger 4. The burner 2 has a burner 2a as a main heat source for hot water supply and a burner 2b as an auxiliary heat source. The burner 2b is used as a heat source for heating and reheating, as will be described later.

Although not shown, each of the burners 2a and 2b is composed of a plurality of burners, and an electromagnetic valve (not shown) is provided in a fuel gas supply path branched to the plurality of burners. Therefore, it is possible to variably control the number of burners (combustion burners) that burn the actual combustion gas. In addition, the flow rate of the fuel gas supplied to the combustion burner can be variably controlled by supplying the fuel gas to the fuel gas supply path before branching via a proportional valve (not shown). Can be done. For example, in each of the burners 2a and 2b, the output heat amount during the combustion operation of the burners 2a can be controlled by the combination of the number of combustion burners and the fuel gas flow rate.

The fan 3 supplies combustion air to the burner 2. The fan 3 has a fan 3a that supplies combustion air to the burner 2a and a fan 3b that supplies combustion air to the burner 2b. The fans 3a and 3b are arranged below the burners 2a and 2b in the height direction of the hot water supply device 100a, respectively. Regarding the fan 3, in FIG. 1, a configuration in which one fan 3a and one 3b are provided for each of the burners 2a and 2b is illustrated, but one fan is commonly provided for the plurality of burners 2a and 2b. It can also be configured.

The heat exchanger 4 includes a heat exchanger 4a provided corresponding to the main heat source, a heat exchanger 4b provided corresponding to the auxiliary heat source, and a heat exchanger 4c for reheating. The heat exchangers 4a and 4b are arranged above the burners 2a and 2b in the height direction of the hot water supply device 100a, respectively. The heat exchangers 4a and 4b are arranged in the vicinity of the exhaust port 1a.

The heat exchanger 4a recovers the heat of the combustion gas supplied by the combustion operation of the burner 2a. The heat exchanger 4b recovers the heat of the combustion gas supplied by the burner 2b. Each of the heat exchangers 4a and 4b is a primary heat exchanger that heats the passing fluid by heat exchange by the actual heat (combustion heat) of the combustion gas of the burner 2, and the fluid by the latent heat of the combustion exhaust gas from the burner 2. It may include a secondary heat exchanger that heats by heat exchange. On the other hand, the heat exchanger 4c exchanges heat between liquids.

The water inlet pipe 5 is connected to a water pipe (not shown) at the water inlet 5a. When the hot water tap is opened and / or when the bath water pouring valve 13 is opened, low-temperature water is introduced from the water inlet 5a to the hot water supply device 100a by the supply pressure of tap water.

The water inlet 5a may be further connected to a device (not shown) that supplies preheated hot water such as a solar hot water utilization device or a fuel cell unit. For example, a switching valve (not shown) for selectively connecting these preheated hot water supply devices and the water pipe to the water inlet 5a may be further arranged. When the preheated hot water supply device and the water inlet 5a are connected by the switching valve, the preheated hot water is introduced into the hot water supply device 100a. The temperature sensor 18 provided in the water entry pipe 5 detects the water entry temperature Tw introduced from the water inlet 5a.

The water inlet pipe 5 is branched into a can body pipe 5b and a bypass pipe 7a via a bypass valve 7. The can body pipe 5b is connected to one end of the heat exchanger 4a. The flow rate ratio of the bypass pipe 7a and the can body pipe 5b to the total flow rate of the water inlet pipe 5 is controlled by the opening degree of the bypass valve 7.

The other end of the heat exchanger 4a is connected to one end of the hot water supply pipe 6. The tap water or preheated hot water supplied from the water inlet pipe 5 to the can body pipe 5b is heated to a predetermined temperature by the heat exchanger 4a and output to the hot water supply pipe 6. A flow rate sensor 14 is arranged in the can body pipe 5b. The flow rate sensor 14 can detect the flow rate (can body flow rate) of the heat exchanger 4a.

On the other hand, the bypass pipe 7a bypasses the heat exchanger 4a and is connected to the hot water supply pipe 6. Therefore, the tap water or preheated hot water supplied from the water inlet pipe 5 to the bypass pipe 7a is output to the hot water supply pipe 6 without being heated by the heat exchanger 4a. In this way, the hot water supply device 100a mixes the high temperature water output from the heat exchanger 4a and the low temperature water that has passed through the bypass pipe 7a, and outputs hot water at an appropriate temperature according to the set temperature from the hot water supply pipe 6. can do.

The other end of the hot water supply pipe 6 is connected to a hot water outlet 6a connected to a hot water supply tap (not shown) or the like. Therefore, hot water having an appropriate temperature controlled to a set temperature is supplied from the hot water supply device 100a to the hot water tap via the hot water outlet 6a according to the opening of the hot water tap.

The hot water supply pipe 6 is further connected to the hot water pouring pipe 13a leading to the bathtub 20. A bath pouring valve 13 is inserted and connected to the hot water pouring pipe 13a. The bath pouring valve 13 can be configured by, for example, an electromagnetic valve that can be opened and closed. By opening the bath hot water pouring valve 13, it is possible to form a path for hot water to be output from the hot water supply pipe 6 to the hot water pouring pipe 13a. As a result, the hot water supply device 100a can include the bathtub 20 at the hot water supply destination in addition to the hot water outlet 6a (hot water tap or the like). In the present specification, the hot water supply from the hot water supply device 100a to the bathtub 20 is referred to as “hot water pouring” and is distinguished from the hot water supply to the hot water outlet 6a (hot water tap, etc.). A flow rate sensor 16 is provided in the hot water pouring pipe 13a. The flow rate sensor 16 can detect the flow rate of hot water poured from the hot water supply device 100a to the bathtub 20.

The hot water supply device 100a further includes a heating function, and includes a heat medium input port 15a from a heating device (floor heating, a heater, etc.) (not shown), a heat medium output port 15b to the heating device, and a heating circulation path 17. Further prepare.

The heating circulation path 17 is formed inside the hot water supply device 100b (housing 1) in order to form a circulation supply path for the heat medium (high temperature water) to the heating appliance, and the return pipe 17a, the forward pipe 17b, and the heating circulation pump. It has a 17c and a bypass valve 17d. One end of the return pipe 17a is connected to the heat medium input port 15a from the heater, and the other end is connected to the input side of the heat exchanger 4b. One end of the forward pipe 17b is connected to the output side of the heat exchanger 4b, and the other end is connected to the heat medium output port 15b. The return pipe 17a, the forward pipe 17b, the heating circulation pump 17c, and the bypass valve 17d are built in the housing 1.

In the hot water supply device 100a, when the heating circulation path 17 is formed by the operation of the heating circulation pump 17c, the heat medium in the heating circulation path 17 can be heated by the burner 2b and the heat exchanger 4b. When the bypass valve 17d is closed, the heating function is realized by forming the heat medium input port 15a, the heat medium output port 15, and the heat medium circulation path including the heating appliance.

Further, the heat medium heated by the heat exchanger 4b passes through the primary path of the heat exchanger 4c. As a result, a heat source for the reheating operation of the bathtub water is secured. By opening the bypass valve 17d even when the heating function is off, a circulation path for the heat medium including the heat exchanger 4c (primary side path) can be formed.

The reheating circulation path 8 is for circulating the hot water 21 of the bathtub 20 (hereinafter, also referred to as the bathtub water 21) in the hot water supply device 100a, and the return pipe 8b, the outgoing pipe 8a, and the reheating circulation pump 10 And have. One end of the return pipe 8b is connected to the circulation adapter 25 in the bathtub 20, and the other end is connected to the secondary side path (input side) of the heat exchanger 4c. One end of the outgoing pipe 8a is connected to the secondary side path (output side) of the heat exchanger 4c, and the other end is connected to the circulation adapter 25.

By the operation of the reheating circulation pump 10, the bathtub water 21 sucked from the circulation adapter 25 is discharged from the circulation adapter 25 via the return pipe 8b, the heat exchanger 4c, and the forward pipe 8a (additional). (Burning circulation path) is formed. When the combustion operation of the burner 2b is turned on during the formation of the reheating circulation path, the bathtub water 21 introduced from the return pipe 8b exchanges heat with the heat medium (high temperature water) of the heating circulation path in the heat exchanger 4c. It is heated. The temperature of the bathtub water 21 can be raised by supplying the heated bathtub water 21 to the bathtub 20 by the going pipe 8a.

A temperature sensor 9b and a water level sensor 11 are connected to the return pipe 8b. A temperature sensor 9a is arranged in the going pipe 8a. The water level sensor 11 is composed of, for example, a pressure sensor, and detects the water level of the bathtub water 21 in the bathtub 20 (hereinafter, also simply referred to as “bathtub water level”) based on the water pressure of the bathtub water 21. The water level sensor 11 is arranged in the area where the bath water 21 infiltrates in the return pipe 8b even when the reheating circulation pump 10 is stopped.

The return pipe 8b is further connected to the hot water pouring pipe 13a at the connection point 8c. As a result, by opening the bath hot water pouring valve 13, the hot water of the hot water supply pipe 6 is passed through the hot water pouring pipe 13a, the connection point 8c, and the forward pipe 8a and the return pipe 8b constituting the reheating circulation path 8. It is introduced into the bathtub 20. As a result, the hot water pouring operation from the hot water supply device 100a can be performed.

The controller 12 can be configured to include, for example, a microcomputer. The controller 12 is electrically connected to the burners 2a, 2b, the fans 3a, 3b, the temperature sensors 9a, 9b, 18, 19, the reheating circulation pump 10, the water level sensor 11, and the bath pouring valve 13. The controller 12 is configured to be supplied with electric power, for example, by being connected to a power source (not shown).

The values detected by the flow rate sensors 14 and 16 and the temperature sensors 9a, 9b, 18 and 19 are input to the controller 12. The flow rate sensors 14 and 16 can be configured by, for example, an impeller type flow meter. The temperature sensors 9a, 9b, 18, 19 can be configured by, for example, a thermistor.

The controller 12 can acquire the incoming water temperature Tw from the detected value of the temperature sensor 18, and can acquire the hot water temperature Th from the detected value of the temperature sensor 19. Further, the output temperature to the bathtub during the hot water pouring operation can be obtained from the detected values of the temperature sensors 9a and 9b. After the pouring operation is completed, the detected values of the temperature sensors 9a and 9b can be the bathtub water temperature.

Further, the controller 12 is communicably connected to the remote controller 30 and the remote controller 50. The communication between these devices may be in accordance with any known standard, and may be wired or wireless.

The remote controller 30 is installed on the wall surface of the bathroom 200 and is for operating the hot water supply device 100a. The remote controller 30 includes a display unit 31 for displaying information and an operation unit 32 for receiving an input setting operation by a user or the like. The display unit 31 is configured to be able to display, for example, the bathtub water level and the temperature. The operation unit 32 is configured to be able to accept, for example, setting operations related to the bathtub water level and temperature.

The remote controller 50 is installed outside the bathroom 200 and is for operating the hot water supply device 100a. The remote controller 50 is typically installed on the wall surface of the kitchen. The remote controller 50 includes a display unit 51 for displaying information and an operation unit 52 for receiving an input setting operation by a user or the like.

The display unit 51 is configured to be able to display the hot water supply set temperature Tr, the bath set temperature Tbr, and the like. The hot water supply set temperature Tr indicates the target temperature of the hot water supply temperature from the hot water outlet 6a. On the other hand, the bath set temperature Tbr indicates the target temperature of the bathtub water 21 in the bathtub 20. The operation unit 52 is configured to be able to accept setting operations related to the operation of the hot water supply device 100a.

The controller 12 controls the operation of the hot water supply device 100a so that the hot water supply device 100a is operated according to the user's instruction based on the input setting operation of the user or the like from the remote controllers 30 and 50.

For example, in the controller 12, the can body flow rate detected by the flow rate sensor 14 is higher than the predetermined minimum operating flow rate (MOQ) in a state where the operation switch of the hot water supply device 100a is turned on by the operation of the remote controllers 30 and 50. In, the combustion operation of the burner 2a is turned on and the hot water supply operation is executed. In the hot water supply operation, the amount of heat generated by the burner 2a (the amount of combustion gas) and the flow rate ratio by the bypass valve 7 are controlled so that the hot water discharge temperature Th detected by the temperature sensor 19 matches the hot water supply set temperature.

When the bath test run or the bath automatic operation is instructed by the operation of the remote controllers 30 and 50, the controller 12 executes the bath hot water filling operation described below. The bathtub filling operation is terminated when the bathtub water level detected by the water level sensor 11 reaches the set water level in the bathtub 20 and the bathtub water temperature detected by the temperature sensors 9a and 9b reaches the bathtub set temperature Tbr. ..

As described above, the preheated hot water by the fuel cell unit or the like can be introduced into the water inlet 5a in the hot water pouring operation, and the hot water supply device 100a according to the present embodiment changes the water input temperature Tw during the hot water pouring operation. It is assumed that the range will be relatively wide. However, even in the hot water supply device 100a in which the preheated hot water is not introduced into the water inlet 5a, it is possible to apply the hot water pouring operation in the low heating mode according to the present embodiment described later in order to respond to the temperature change of tap water. is there.

Further, the hot water supply device 100a according to the present embodiment is configured so that hot water injection and hot water supply can be operated at the same time. That is, it is assumed that hot water is supplied to both the hot water outlet 6a and the hot water pouring pipe 13a (bathtub 20) by opening the hot water tap during the hot water pouring operation.

Here, the hot water outlet temperature control by heating on the hot water supply circuit side, specifically, the heat exchanger 4a will be described. When the hot water temperature Th of the temperature sensor 19 can be controlled to the bath set temperature Tbr by the hot water temperature control, the hot water of the hot water supply pipe 6 is introduced into the bathtub 20 by opening the hot water pouring valve 13. Hot water operation can be realized.

The controller 12 calculates the command value of the output heat amount of the burner 2a in the hot water temperature control. In a hot water supply device, the amount of heat generated is generally calculated in units of "number". The number = 1 corresponds to the amount of heat required to raise the hot water temperature by 25 ° C. under a flow rate of 1 (L / min). Therefore, in the following, the command value of the amount of heat generated by the burner 2a is also referred to as the required number Qrq.

During the hot water pouring operation, the required number Qrq is calculated according to the product of the temperature rise amount ΔT from the water inlet temperature Tw (temperature sensor 18) and the flow rate Qt of the hot water pouring pipe 13a (hereinafter, also referred to as the total flow rate Qt). Can be done. In the hot water pouring operation, the required temperature rise amount ΔT is indicated by ΔT = Tbr−Tw using the bath set temperature Tbr and the water entry temperature Tw. Therefore, the required number Qrq can be calculated by the following formula (1).

Qrq = Qt × (Tbr-Tw) / 25 ... (1)
On the other hand, there is a minimum value for the amount of output heat that can be controlled by the burner 2a. Specifically, the generation of the burner 2a when the number of combustion burners in the burner 2a is set to the minimum value (for example, one) and the fuel flow rate is set to the minimum value for stabilizing the combustion state of the burner. There is a calorific value, that is, a controllable minimum calorific value (hereinafter, also referred to as "minimum number Qa"). The burner 2b also has a minimum number. As the heating specifications of the burners 2a and 2b, the minimum number of each indicating the minimum value of the controllable calorific value range is predetermined.

In the case where the required number Qrq is lower than the minimum number Qa, there is a concern that the hot water discharge temperature (pouring temperature) to the bathtub will be higher than the bath set temperature Tbr due to the hot water pouring operation accompanied by the operation of the burner 2a. Will be done. In such a case, for example, the final bath water temperature can be made to match the bath set temperature by combining the hot water pouring operation (minimum number) and the water pouring operation in which the burner 2a is stopped. However, in this case, there is a problem that it becomes difficult to control the hot water discharge temperature Th when the hot water supply tap is opened and the hot water supply operation is simultaneously executed during the water injection operation.

Therefore, in the hot water supply device 100b according to the present embodiment, the hot water pouring operation when the required heating amount is low (hereinafter, also referred to as the hot water pouring operation in the low heating mode) is executed as described below.

FIG. 2 shows a conceptual diagram for explaining the state of the reheating circulation path 8 during the hot water pouring operation.
With reference to FIG. 2, the reheating circulation pump 10 is stopped during the hot water pouring operation. Therefore, the hot water supplied from the pouring pipe 13a to the connection point 8c reaches the bathtub 20 from the connection point 8c via the return pipe 8b, the reheating circulation pump 10, the heat exchanger 4c, and the outgoing pipe 8a. The flow is divided into the first path P1 and the second path P2 which reaches the bathtub 20 via the return pipe 8b without passing through the heat exchanger 4c.

In the present embodiment, the temperature sensors 9a and 9b are provided in the forward pipe 8a and the return pipe 8b, respectively. Therefore, the temperature sensor 9a can detect the output temperature T1 of hot water from the first path P1. Similarly, the temperature sensor 9b can detect the output temperature T2 of hot water from the second path P2.

In the hot water pouring operation in the low heating mode, the amount of heating by the auxiliary heat source (burner 2b) becomes a predetermined fixed number Y (for example, equivalent to the minimum number in the auxiliary heat source) while the heating circulation pump 17c is operating. Be controlled. The heat medium in the heating circulation path 17 is heated by the heat amount of the constant number Y, and the heat exchange in the heat exchanger 4c results in a fixed heating amount QX with respect to the hot water flowing through the first path P1. [Kcal / h] is given.

In the hot water supply device 100a, the amount of output heat generated by the combustion of the burner 2b is indirectly related to the heating of hot water flowing through the first path P1 in the heat exchanger 4c via the heat medium heated by the heat exchanger 4b. Used. Due to such indirect heating, the fixed heating amount QX becomes smaller than the output heat amount of the auxiliary heat source (burner 2b). That is, regarding the heating amount of the hot water poured into the bathtub 20, the minimum value (minimum heating amount) of the heating by the auxiliary heat source (burner 2b) is lower than that of the heating by the burner 2a (main heat source). Is possible.

On the other hand, since the hot water flowing through the second path is not heated by the heat exchanger 4c, a temperature difference due to the fixed heating amount QX occurs between the first path P1 and the second path P2.

Therefore, between the flow rate Q1 [L / min] of the first path P1, the temperature difference (temperature rise amount) between the output temperature T1 and the output temperature T2, and the fixed heating amount QX by the heat exchanger 4c, the following The relationship of Eq. (2) is established. By modifying the equation (2), the flow rate Q1 of the first path P1 is represented by the following equation (3).

Q1 x (T1-T2) x 60 = QX ... (2)
Q1 = QX / {(T1-T2) x 60} ... (3)
The fixed heating amount QX can be obtained in advance by an actual machine test or the like in which the auxiliary heat source (burner 2b) is operated with the above-mentioned constant number Y. Therefore, the flow rate Q1 can be calculated from the output temperatures T1 and T2 detected by the temperature sensors 9a and 9b according to the equation (3).

The total flow rate Qt detected by the flow rate sensor 16 in FIG. 1 corresponds to the sum of the flow rate Q2 [L / min] of the second path P2 and the flow rate Q1. Therefore, if the distribution ratio k (0 <k <1.0) is defined by k = Q1 / Qt, the flow rate Q1 calculated by the equation (3) and the detected value (Qt) of the flow rate sensor 16 are used. , The distribution ratio k can be calculated.

Further, using the distribution ratio k, it can be expressed as Q1 = k · Qt and Q2 = (1-k) · Qt. Therefore, the following equation (4) is established using the bath set temperature Tbr.

(Tbr-Th) x Qt = (T1-Th) x Q1 + (T2-Th) x Q2 ... (4)
Since Qt = Q1 + Q2, Th can be eliminated from the equation (4) to obtain the following equation (5). In the formula (5), the flow rate and temperature of the first path P1 and the second path P2 for setting the average temperature of the hot water supplied by the first path P1 and the second path P2 as the bath set temperature Tbr. Shows the relationship.

Tbr × Qt = T1 × Q1 + T2 × Q2… (5)
By solving the equation (5) for T1, the target temperature T1 * corresponding to the target value of the output temperature T1 of the first path P1 is obtained by the following equation (6).

T1 * = {Tbr x Qt-T2 x (1-k) x Qt} / (k x Qt)
= {Tbr-T2 × (1-k)} / k… (6)
In the formula (6), the distribution ratio k can be obtained from the above formula (3) and the detected value of the total flow rate Qt. Therefore, the target temperature T1 * in the first path P1 can be obtained by using the values detected by the temperature sensors 9a and 9b (output temperatures T1 and T2) and the values detected by the flow rate sensor 16 (total flow rate Qt). it can.

In this way, the bath water is controlled by controlling the output temperature T1 of the first path P1 passing through the heat exchanger 4c without directly detecting the flow rates of the first path P1 and the second path P2 after the flow split. A hot water pouring operation for setting the temperature to the bath set temperature Tbr can be executed.

In this embodiment, the burner 2a corresponds to one embodiment of the "main heat source" and the heat exchanger 4a corresponds to one embodiment of the "first heat exchanger". Further, the burner 2b corresponds to an embodiment of the "auxiliary heat source", and the heat exchanger 4c corresponds to an embodiment of the "second heat exchanger". Further, the reheating circulation path 8 corresponds to an embodiment of the "first circulation path", and the heating circulation path 17 corresponds to an embodiment of the "second circulation path", and the heat exchanger 4b (FIG. 1) corresponds to one embodiment of the "third heat exchanger". Further, the controller 12 corresponds to a "controller".

Further, in the reheating circulation path 8, the reheating circulation pump 10 corresponds to an embodiment of the “circulation pump”, the outgoing pipe 8a corresponds to an embodiment of the “first pipe”, and the return pipe 8b corresponds to an embodiment. Corresponds to one embodiment of the "second pipe". Further, the temperature sensor 9a corresponds to an embodiment of the "first temperature detector", and the temperature sensor 9b corresponds to an embodiment of the "second temperature detector".

FIG. 3 is a flowchart illustrating a control process of the bath water filling operation including the hot water pouring operation in the low heating mode by the hot water supply device according to the present embodiment.

In the control process of the bath water filling operation shown in FIG. 3, for example, when the bath water filling is activated by the operation of the remote controllers 30 and 50, the water entry temperature Tw to the hot water supply device 100a and the bath set temperature Tbr are set. It is executed by the controller 12 when the temperature difference is small, i.e. when the application of the low heating mode is selected. Alternatively, the low heating mode may be selected when the required number QRq calculated by the equation (1) is lower than the predetermined reference value QR at the start of the bath filling operation. The reference value Qr can be set in advance corresponding to the minimum number of the burner 2a.

With reference to FIG. 3, the controller 12 is opened by opening the bath pouring valve 13 in a state where the burner 2a (main heat source) is stopped (combustion off) by step 100 (hereinafter, simply referred to as “S”) 100. Pour hot water.

Further, after the start of pouring, the controller 12 executes the pouring completion determination by S110 to S130. For example, in S110, the total flow rate Qt of the hot water pouring pipe 13a detected by the flow rate sensor 16 is acquired, and in S120, the total flow rate Qt acquired in S110 is integrated (time integration) to pour the amount of hot water in the hot water pouring operation. Vt is calculated. Then, in S130, it is determined whether or not the pouring amount Vt has reached the determination value Vth corresponding to the set water level in the bathtub 20.

When the pouring amount Vt reaches the determination value Vth (when YES is determined in S130), the controller 12 determines that the pouring is completed, and closes the bath pouring valve 13 by S140 to end the pouring operation. .. On the other hand, the controller 12 determines that the pouring is incomplete until the pouring amount Vt reaches the determination value Vth (when NO is determined in S130), and the temperature control in the low heating mode by S200 is repeatedly executed. Continue pouring below.

FIG. 4 is a flowchart illustrating details of temperature control in the low heating mode in S200. S200 of FIG. 3 has S210 to S250 shown in FIG.

With reference to FIG. 4, the controller 12 acquires the output temperatures T1 and T2 detected by the temperature sensors 9a and 9b and the total flow rate Qt detected by the flow rate sensor 16 by S210. For the total flow rate Qt, it is also possible to share the value acquired in S110.

The controller 12 calculates the distribution ratio k by S220. Specifically, the T1 and T2 acquired in S210 and the preset fixed heating amount QX are substituted into the equation (3) to calculate the flow rate Q1 of the first path P1, and further, the calculated flow rate. The distribution ratio k can be calculated by dividing Q1 by the detected value of the total flow rate Qt (k = Q1 / Qt).

Further, the controller 12 calculates the target temperature T1 * of the first path P1 by S230. Specifically, by substituting the bath set temperature Tbr, the distribution ratio k calculated by S220, and the output temperature T2 detected by the temperature sensor 9b into the above equation (6), the target temperature T1 * Can be calculated.

In S240, the controller 12 calculates the integrated average value T1A of the output temperature T1 in the first path P1 from the start of temperature control based on the integration of the detected temperatures by the temperature sensor 9b from the start time of temperature control in S200 to the present time. To do. The integrated average value T1A is updated every time S240 is executed.

Further, the controller 12 executes the heating amount control of the first path P1 by the auxiliary heat source based on the integrated average value T1A of the output temperature T1 of the first path P1 and the target temperature T1 * by S250.

FIG. 5 is a conceptual diagram showing a first example of heating amount control by an auxiliary heat source by S250.
With reference to FIG. 5, the heating amount control by the auxiliary heat source can be realized by switching the operation and stop of the burner 2b (auxiliary heat source) by comparing the integrated average value T1A of the output temperature T1 and the target temperature T1 *. ..

For example, the control by S250 is started in the combustion on state in which the burner 2a (auxiliary heat source) outputs the above-mentioned constant number Y. In the combustion on state, when the integrated average value T1A becomes equal to or higher than the target temperature T1 * (T1A ≧ T1 *), the controller 12 stops the combustion of the burner 2b (combustion off state). The combustion on state corresponds to the "first state", and the combustion off state corresponds to the "second state".

On the other hand, when the integrated average value T1A of the output temperature T1 is lower than the determination value (T1 * -α) in the combustion off state, the controller 12 sets the burner 2a in the combustion on state (constant number Y). .. In this way, by turning on and off the combustion of the burner 2b (auxiliary heat source) at a constant output according to the increase and decrease of the integrated average value T1A, the integrated average value T1A of the output temperature T1 of the first path P1 is set. The target temperature T1 * set by the equation (6) can be controlled.

FIG. 6 shows a conceptual diagram illustrating a second example of heating amount control by the auxiliary heat source by S250.

With reference to FIG. 6, in the second example, the flow rate adjusting valve 27 for the heat medium is further arranged in the heating circulation path 17 connected to the primary side path of the heat exchanger 4c. Then, the heating amount control by the auxiliary heat source is performed by controlling the opening degree of the flow rate adjusting valve 27 based on the temperature deviation ΔT (ΔT = T1 * -T1A) indicating the insufficient amount of the integrated average value T1A of the output temperature T1 with respect to the target temperature T1 *. It will be realized.

FIG. 7 shows a conceptual diagram illustrating an example of opening degree control of the flow rate adjusting valve 27.
With reference to FIG. 7, in the second example, the opening X of the flow rate adjusting valve 27 is set from the minimum opening Xmin (preferably fully closed) according to the temperature deviation ΔT (ΔT = T1 * -T1A). It can be controlled between the maximum opening Xmax.

For example, when ΔT ≦ 0, that is, T1 * ≦ T1A, the flow rate adjusting valve 27 is controlled to the minimum opening degree Xmin. When the flow rate adjusting valve 27 is controlled to be fully closed at X = Xmin, the combustion of the burner 2b is also stopped.

On the other hand, in the region of ΔT> 0, the flow rate adjusting valve 27 opens as the temperature deviation ΔT increases in a state where the burner 2b is operated so as to output a constant number Y (combustion on state in FIG. 5). The degree X is controlled to be large. In the state of X = Xmax, a predetermined fixed heating amount QX is given to the hot water flowing through the first path P1 as in the combustion on state of FIG.

In the second example, in the region where the opening degree X <Xmax, a calorie smaller than the fixed heating amount QX can be given to the hot water flowing through the first path P1, so that the hot water flowing through the first path P1 is more likely to be compared with the first example. The integrated average value T1A of the output temperature T1 in the first path P1 can be finely controlled to the target temperature T1 *.

In this way, in both the first example and the second example, the output temperature of the first path P1 is obtained by heating the hot water passing through the heat exchanger 4c by the output heat amount of the burner 2b (auxiliary heat source). The integrated average value T1A of the output temperature T1 of T1 can be controlled to the target temperature T1 *. By controlling the integrated average value T1A of the output temperature T1 to the target temperature T1 * calculated by reflecting the bath set temperature Tbr by the equation (6), the average temperature of the bathtub water 21 poured into the bathtub 20 is controlled. Can be controlled to the bath set temperature Tbr.

With reference to FIG. 3 again, the controller 12 sets the average temperature of the bath water 21 poured into the bathtub water 21 by the temperature control (low heating mode) by S200 during the hot water pouring operation (NO determination in S130). To control.

Further, at the end of the hot water pouring operation (S140), the controller 12 compares the actual bathtub water temperature Tb detected by the temperature sensor 9a or 9b by S150 with the bath set temperature Tbr.

When the bathtub water temperature Tb after the completion of the hot water pouring operation is lower than the bath set temperature Tbr (when NO is determined in S150), the controller 12 executes the reheating operation in S160. As described above, in the reheating operation, the burner 2b is burned in a state where the reheating circulation pump 10 is operated to form the reheating circulation path, so that the burner 2b is burned through the heat medium of the heating circulation path 17. , The bath water 21 is heated by the heat exchanger 4c.

When the bathtub water temperature Tb is equal to or higher than the bath set temperature Tbr (when YES is determined in S150), the controller 12 ends the bath filling operation by S170. Therefore, when the reheating operation is started by S160, the reheating operation is continued until the bathtub water temperature Tb reaches the bath set temperature Tbr. On the other hand, if Tb ≧ Tbr at the time of completion of pouring, the bath filling operation is completed without executing the reheating operation (S160).

As described above, according to the hot water supply device according to the present embodiment, the main heat source (burner 2a) on the hot water supply circuit side is indirectly supplied to the bathtub 20 by the auxiliary heat source (burner 2b) for reheating. By heating a part of the hot water to be generated, it is possible to realize the hot water pouring operation in the low heating mode. In the configuration example of FIG. 1, since heating by the auxiliary heat source is indirect, the main heat source determines the minimum heat amount in the heat exchanger 4c when the auxiliary heat source outputs the controllable minimum heat amount (minimum number). It can be lower than the minimum heat amount in the heat exchanger 4a when the minimum controllable heat amount (minimum number) is output. As a result, the fixed heating amount QX in the low heating mode is narrowed down from the minimum heating amount by the main heat source (burner 2a), so that it is possible to cope with the lower heating side.

Further, using the detected temperatures of the heated hot water that passes through the heat exchanger 4c and the unheated hot water that does not pass through the heat exchanger 4c, the auxiliary heat source is based on the detected temperature of a part of the heated hot water. By controlling the amount of heat, the average temperature of the bathtub water 21 output to the bathtub 20 by the hot water pouring operation can be controlled to the bath set temperature Tbr.

If the temperature of the bathtub water 21 after the hot water pouring operation is lower than the bath set temperature Tbr, the reheating operation is performed to end the bath filling operation at the hot water temperature according to the bath set temperature Tbr. can do.

In addition, in FIG. 1, the auxiliary heat source (burner 2b) for reheating indirectly heats the hot water of the reheating circulation path 8 for the hot water supply device 100a having the reheating function and the heating function. An example of applying the hot water pouring operation in the low heating mode has been described. In such a configuration, even when the specifications (heating amount) of the burner 2a (main heat source) and the burner 2b (auxiliary heat source) are the same, the pouring operation in the low heating mode according to the present embodiment is realized. Can be done.

On the other hand, when the specifications (heating amount) of the burner 2b (auxiliary heat source) are lower than those of the burner 2a (main heat source), the low heating according to the present embodiment is applied to the hot water supply device that does not have the heating function. It is possible to apply the mode of hot water pouring operation.

FIG. 8 is a schematic view illustrating a modified example of the configuration of the hot water supply device according to the embodiment of the present invention.
With reference to FIG. 8, since the hot water supply device 100b according to the modified example does not have a heating function, the heat medium input port 15a and the heat medium output port 15b are compared with the configuration of the hot water supply device 100a shown in FIG. , The arrangement of the heating circulation path 17 (return pipe 17a, outgoing pipe 17b, heating circulation pump 17c, and bypass valve 17d) and the heat exchanger 4c is omitted.

In the hot water supply device 100b, one end of the return pipe 8b (reheating circulation path 8) is connected to the circulation adapter 25 in the bathtub 20 as in FIG. 1, while the other end is one end of the heat exchanger 4b. Is connected with. Further, one end of the outgoing pipe 8a is connected to the other end of the secondary side path of the heat exchanger 4b, and the other end is connected to the circulation adapter 25 as in FIG.

Therefore, the hot water in the reheating circulation path 8 is directly heated by the heat exchanger 4b using the amount of heat from the burner 2b (auxiliary heat source) without going through the heat medium in the configuration example of FIG. That is, in the configuration example of FIG. 8, the heating mode of the hot water supplied to the bathtub 20 is the same between the burner 2a (main heat source) and the burner 2b (auxiliary heat source). In the configuration example of FIG. 8, the heat exchanger 4b corresponds to one embodiment of the “second heat exchanger”, and the “third heat exchanger” is not arranged.

Even in such a configuration, if the heating specifications (for example, the minimum number) by the burner 2b (auxiliary heat source) are lower than the heating specifications (for example, the minimum number) of the burner 2a (main heat source), The minimum heat amount in the heat exchanger 4b when the auxiliary heat source outputs the controllable minimum heat amount (minimum number), and the heat exchanger when the main heat source outputs the controllable minimum heat amount (minimum number). It can be lower than the minimum heating amount in 4a. Therefore, the fixed heating amount QX for the hot water flowing through the first path P1 (FIG. 2) is larger than the minimum heating amount in the heat exchanger 4a when the burner 2a (main heat source) burns at the minimum number. It can be made smaller. Thereby, it is understood that the hot water supply device 100b can also perform the hot water pouring operation in the low heating mode in the hot water supply device 100a described above in the same manner as described with reference to FIGS. 3 to 5.

Further, in the present embodiment, gas is exemplified as the fuel of the burners 2a and 2b, but any fuel can be burned by the burners 2a and 2b as long as the output heat amount can be controlled. Alternatively, the "main heat source" and "auxiliary heat source" are not limited to those that generate heat by combustion, as long as they can be turned on (operated) and off (stopped), and the output heat amount can be controlled. It is possible to apply the equipment of.

It should be considered that the embodiments disclosed this time are exemplary in all respects and not restrictive. The scope of the present invention is shown by the scope of claims rather than the above description, and it is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

1 Housing, 1a exhaust port, 2,2a, 2b burner, 3,3a, 3b fan, 4,4a, 4b, 4c heat exchanger, 5 water inlet piping, 5a water inlet, 5b can body piping, 6 hot water supply piping, 6a Outlet, 7 Bypass valve (hot water supply circuit), 7a Bypass piping, 8 Reheating circulation path, 8a Outgoing piping (Reheating circulation path), 8b Return piping (Reheating circulation path), 8b piping, 8c connection Point, 9a, 9b, 18,19 Temperature sensor, 10 Reheating circulation pump, 11 Water level sensor, 12 controller, 13 Hot water valve, 13a hot water piping, 14,16 Flow sensor, 15,15b Heat medium output port, 15a Heat medium Input port, 17 heating circulation path, 17a return pipe (heating circulation path), 17b outbound piping (heating circulation path), 17c heating circulation pump, 17d bypass valve (heating circulation path), 20 bathtub, 21 bathtub water, 25 circulation adapter , 27 Flow control valve, 30,50 remote control, 100a, 100b hot water supply device, 200 bathroom, 300a hot water supply system, P1 first path, P2 second path, Qt total flow rate, T1, T2 output temperature, T1A integrated average value , T1 output temperature, T1 * target temperature, Tb bath water temperature, Tbr bath set temperature, Vt hot water amount, Vth judgment value, X opening (flow control valve).

Claims (7)

A hot water supply device that includes a bathtub at the hot water supply destination.
The main heat source for hot water supply and
A first heat exchanger that heats the incoming water with the amount of heat from the main heat source and outputs it to the hot water supply pipe.
The first circulation path of bathtub water, which is communicated with the bathtub,
A hot water pouring pipe arranged between the hot water supply pipe and the first circulation path,
A bath pouring valve and a flow rate detector provided in the pouring pipe,
It is provided with an auxiliary heat source used for heating hot water flowing through the first circulation path.
The first circulation path is
A second heat exchanger for heating the hot water flowing through the first circulation path using the amount of heat from the auxiliary heat source, and
A circulation pump for circulating the bath water in the first circulation path, and
A first pipe connecting the bathtub and one end of the second heat exchanger,
A second pipe connecting the bathtub and the other end of the second heat exchanger,
Including the connection point with the hot water pouring pipe provided in any of the second pipes,
The hot water supply device
The main heat source, the auxiliary heat source, the bath pouring valve, and a controller for controlling the circulation pump are further provided.
The controller stops the operation of the main heat source and uses the output heat amount of the auxiliary heat source in the hot water pouring operation to the bathtub in which the bath water pouring valve is opened while the circulation pump is stopped. A hot water supply device having a low heating mode in which a part of hot water flowing through the first circulation path is heated by a second heat exchanger. In the first circulation path, in the hot water pouring operation, hot water from the hot water pouring pipe reaches the bathtub from the connection point via the second heat exchanger and the first pipe. It is configured to diverge into one path and a second path from the connection point to the bathtub via the second pipe without passing through the second heat exchanger.
The hot water supply device
A first temperature detector that detects the output temperature from the first pipe to the bathtub,
Further provided with a second temperature detector for detecting the output temperature from the second pipe to the bathtub.
The controller makes the integrated average value of the detected temperatures by the first temperature detector match the target temperature set by reflecting the set temperature of the bathtub water in the pouring operation in the low heating mode. Therefore, the auxiliary heat source is controlled so as to switch between a first state in which the operation is performed with a predetermined constant output heat amount and a second state in which the operation is stopped.
The fixed heat amount by the second heat exchanger when the auxiliary heat source is in the first state is the first heat exchanger when the main heat source outputs the minimum value in the controllable heat amount range. The hot water supply device according to claim 1, which is lower than the minimum heating amount in. In the hot water pouring operation in the low heating mode, the controller has the temperature difference between the first and second temperature detection values by the first and second temperature detectors, the fixed heating amount, and the said. Using the flow rate detection value by the flow rate detector, the distribution ratio of the flow rate of the first path to the flow rate in the pouring pipe is calculated, and the calculated distribution ratio, the set temperature, and the second The hot water supply device according to claim 2, wherein the target temperature is calculated according to the temperature detection value and the flow rate detection value. The hot water supply device
A second circulation path that circulates the heat medium,
Further provided with a third heat exchanger that heats the heat medium of the second circulation path by the output heat amount of the auxiliary heat source.
The second heat exchanger is connected to the second circulation path between the primary side path through which the heat medium passes and the secondary side path through which hot water in the first circulation path passes. The hot water supply device according to claim 1, wherein the hot water supply device is configured to exchange heat between liquids. The hot water supply device
A second circulation path that circulates the heat medium,
Further provided with a third heat exchanger that heats the heat medium of the second circulation path by the output heat amount of the auxiliary heat source.
The second heat exchanger is connected to the second circulation path between the primary side path through which the heat medium passes and the secondary side path through which hot water in the first circulation path passes. Is configured to exchange heat between liquids
In the hot water pouring operation in the low heating mode, the controller sets the auxiliary heat source to the first state and the auxiliary heat source based on the comparison between the integrated average value of the first temperature detector and the target temperature. The hot water supply device according to claim 2 or 3, which controls any of the second states. The hot water supply device
Further provided with a flow rate adjusting valve for the heat medium provided in the second circulation path,
In the hot water pouring operation in the low heating mode, when the auxiliary heat source is in the first state, the controller of the flow rate adjusting valve responds to the shortage of the integrated average value with respect to the target temperature. The hot water supply device according to claim 5, further controlling the opening degree. The first and second heat exchangers are configured to heat hot water flowing through by the amount of heat from each of the main heat source and the auxiliary heat source in the same manner.
The hot water supply device according to any one of claims 1 to 3, wherein the minimum heat amount that can be controlled by the auxiliary heat source is lower than the minimum heat amount that can be controlled by the main heat source.

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