JP7546903B2 - Hot water supply equipment - Google Patents

Description

This disclosure relates to a water heater.

Patent Document 1 discloses a water heater that can reduce energy consumption. The water heater disclosed in Patent Document 1 is equipped with a water supply control means. This water supply control means supplies unheated water to the bathtub via the water passage after the reservation time and reservation temperature are set by the reservation setting means and before the reservation time arrives.

JP 2011-141101 A

In the water heater of Patent Document 1, unheated water is supplied to the bathtub before the scheduled time for scheduled operation arrives. If the outside air temperature is high, the heat of the outside air is transferred to the water stored in the bathtub by unheated water supply, and the temperature of the stored water rises. This water heater can reduce gas energy consumption because part of the energy consumed to make the water in the bathtub at an appropriate temperature can be covered by natural energy. However, there is a concern that simply supplying water without heating may result in situations in which the heat based on the outside air cannot be used efficiently. For example, if the bathtub has a structure with excellent insulation, the heat from the outside air is not easily transferred to the water stored in the bathtub, making it difficult to efficiently raise the temperature of the unheated water stored in the bathtub. In addition, there are also possible cases other than these where the heat based on the outside air cannot be used efficiently.

Therefore, one objective of this disclosure is to provide a water heater that can repeatedly supply higher temperature water to a bathtub without firing a burner.

The hot water supply device according to the present disclosure includes:
A water pipe through which water introduced from the outside passes;
A burner for burning gas;
a heat exchanger that transfers heat generated by the burner to water passing through a portion of the water pipe;
having
A hot water supply device that at least performs an operation of supplying water heated by the heat exchanger to a bathtub,
an acquisition unit that acquires temperature-related information including information on the water temperature in the water pipe or information on factors that affect the water temperature in the water pipe;
A supply unit that supplies water in the water pipe to the bathtub;
A control unit that controls the operation of the burner and the supply unit;
having
The control unit repeatedly controls the supply unit to supply water from the water pipe to the bathtub without causing the burner to perform combustion each time the temperature-related information satisfies a predetermined condition indicating an increase in the water temperature in the water pipe.

A water heater according to one aspect of the present disclosure can repeatedly supply higher temperature water to a bathtub without firing a burner.

FIG. 1 is a front view illustrating an external appearance of a water heater according to a first embodiment. FIG. 2 is a schematic circuit diagram conceptually illustrating the internal configuration of the water heater of FIG. FIG. 3 is a block diagram illustrating a schematic example of the electrical configuration of the controller and the remote controller that constitute the hot water supply device of FIGS. FIG. 4 is a flowchart illustrating a flow of supply control performed in the hot water heater of the first embodiment.

The following description relates to one embodiment of a water heater. Note that the features [1] to [7] described below may be combined in any manner that does not contradict each other.

[1] a water pipe through which water is introduced from the outside;
A burner for burning gas;
a heat exchanger that transfers heat generated by the burner to water passing through a portion of the water pipe;
having
A hot water supply device that at least performs an operation of supplying water heated by the heat exchanger to a bathtub,
an acquisition unit that acquires temperature-related information including information on the water temperature in the water pipe or information on factors that affect the water temperature in the water pipe;
A supply unit that supplies water in the water pipe to the bathtub;
A control unit that controls the operation of the burner and the supply unit;
having
The control unit repeatedly controls the supply unit to supply water from the water pipe to the bathtub without causing the burner to perform combustion each time the temperature-related information satisfies a predetermined condition indicating an increase in the water temperature in the water pipe.

The water heater of [1] above can repeatedly supply water from the water pipe to the bathtub without the burner burning every time a predetermined condition indicating an increase in the water temperature in the water pipe is met. This water heater supplies unheated water from the water pipe (without the burner burning) every time a condition indicating an increase in the water temperature in the water pipe is met, so it can repeatedly supply water at higher temperatures to the bathtub without consuming gas energy. This allows the bathtub to be filled while reducing gas energy.

[2] The hot water supply device described in [1] above has the following features: The temperature-related information includes information about the outside air temperature. The predetermined condition includes a condition that the outside air temperature is equal to or higher than a threshold temperature while the water in the water pipe is not being supplied to the outside and continues for a predetermined period of time or more.

The water heater of [2] above can repeatedly supply water from the water pipe to the bathtub without causing the burner to burn, each time the condition that "a state in which the water in the water pipe is not being supplied to the outside and the outside air temperature is equal to or higher than the threshold temperature continues for a predetermined period of time or more" is met. This water heater can supply unheated water from the water pipe to the bathtub (without burning the burner) after reliably confirming that the water pipe has been warmed by the outside air temperature for a predetermined period of time or more. This makes it possible to prevent unheated supply operation from being performed when the water temperature is low, making it easier to repeatedly supply warm water.

For example, when the outside air temperature is sufficiently high, such as in summer, the water pipe is more easily heated by the outside air than the water in the bathtub, which has a high degree of insulation, and the water temperature inside is more likely to rise. Therefore, if water from the water pipe, which reflects the outside air temperature, is supplied to the bathtub, it is easier to supply hotter water to the bathtub without burning the burner. Furthermore, when the outside air temperature is high, if cold water is stored again in the water pipe after being supplied without heating, this cold water is also easily heated again, so the temperature of the stored cold water is also likely to rise. If the water in the water pipe, which is easily heated in this way, is repeatedly supplied to the bathtub, it is easier to supply more hotter water to the bathtub without burning the burner.
[3] The hot water supply device according to [1] or [2] above, further comprising the following features: the temperature-related information includes information on an inlet water temperature of the water entering the water pipe, and the predetermined condition includes a condition that the inlet water temperature is equal to or higher than a predetermined value.

The water heater described in [3] above can supply water from the water supply pipe to the bathtub without the burner burning after confirming that the inlet water temperature has reached a predetermined value or higher. This makes it possible to prevent non-heated supply operation when the water temperature is low, making it easier to repeatedly supply warm water.

[4] The hot water supply device according to any one of [1] to [3] above has the following features: The control unit repeatedly controls the supply unit to supply a reference amount of water from the water pipe to the bathtub without causing the burner to perform combustion each time the temperature-related information satisfies the predetermined condition.

The hot water supply device described in [4] above supplies a standard amount of water from the water supply pipe each time the above-mentioned specified conditions are met, making it easier to reduce variations in the temperature of the water supplied when the conditions are met.

[5] The hot water supply device of [4] has the following features. The hot water supply device of [5] has a housing, a hot water supply side circuit including the heat exchanger, and a bath side circuit having a pipe branched from the hot water supply side circuit. The hot water supply side circuit and the bath side circuit are housed in the housing. The water passage pipes include a first water passage pipe provided in the hot water supply side circuit and a second water passage pipe provided in the bath side circuit. The reference water volume is determined based on a first water volume that is the water volume held in the first water passage pipe, a second water volume that is the water volume held in the second water passage pipe, and a third water volume that is the water volume held in a third water passage pipe that is a pipe connected to the first water passage pipe and is provided outside the housing.

The water heater of [5] above can determine the amount of water to be supplied (reference water amount) when the conditions are met based on the amount of water held in the water pipes (first water pipe, second water pipe, third water pipe) at predetermined positions, making it easier to stabilize the temperature of the water to be supplied when the conditions are met.

[6] The hot water supply device of [5] further includes a water volume calculation unit that calculates the sum of the first water volume and the second water volume based on the operation of the hot water supply circuit and the bath side circuit.

The hot water supply device of [6] above can calculate the sum of the first water volume and the second water volume based on the operation of the hot water supply side circuit and the bath side circuit, making it easy to reduce costs and increase versatility.

[7] The hot water supply device of [5] or [6] further includes an inlet water temperature detection unit that detects the temperature of water introduced from the outside, and a third water volume calculation unit that calculates the third water volume based on the time from when the hot water supply device transitions from a non-hot water supply state to a hot water supply state until the temperature detected by the inlet water temperature detection unit drops by a predetermined temperature.

The water heater described above in [7] can determine how much water present outside the water heater should be used based on the inlet water temperature.

First Embodiment
The following description relates to the first embodiment.
(Basic configuration)
The hot water supply device 1 shown in Fig. 1 and Fig. 2 is a device that at least performs the operation of supplying water heated by the heat exchangers 6, 56 to the bathtub 60, and is configured as a bath and hot water supply system equipped with a function of supplying hot water to the bathtub 60 and a function of circulating and heating the water in the bathtub 60. The hot water supply device 1 has an external appearance as shown in Fig. 1. The hot water supply device 1 has a configuration as shown in Fig. 2, and mainly includes a hot water supply side circuit 2 and a bath side circuit 3. As shown in Figs. 1 and 2, the hot water supply device 1 has a housing 5, the hot water supply side circuit 2 including the heat exchanger 6, and the bath side circuit 3 having a pipe (drop pipe 70) branched from the hot water supply side circuit 2. As shown in Figs. 1 and 2, the hot water supply device 1 has the hot water supply side circuit 2 and the bath side circuit 3 housed in the housing 5.

As shown in FIG. 2, the hot water supply side circuit 2 includes a hot water supply side water passage, a gas burner 4, a heat exchanger 6, etc. The hot water supply side circuit 2 functions as a circuit that heats tap water supplied from the outside and supplies hot water. The bath side circuit 3 includes a bath side water passage, a gas burner 54, a heat exchanger 56, a circulation pump 62, thermistors 64, 65, etc. The bath side circuit 3 is used for circulating heating when filling the bathtub, reheating the bathtub, etc.

In the hot water supply side circuit 2, the pipeline consisting of the water inlet pipe 12, heat transfer pipe 8a, piping 20, heat transfer pipe 7a, and hot water outlet pipe 10 functions as the hot water supply side water passage. The water inlet pipe 12 is a flow path (pipe) into which water flows from the water inlet 16. The hot water outlet pipe 10 is a flow path (pipe) that sends hot water to the hot water outlet 18. The gas burner 4 corresponds to an example of a burner. The gas burner 4 functions as a hot water supply side burner, and burns the combustion gas to generate combustion exhaust. The heat exchanger 6 functions as a hot water supply side heat exchanger. The heat exchanger 6 is a part that transfers heat generated by the gas burner 4 to the water passing through the hot water supply side water passage (the pipeline consisting of the water inlet pipe 12, heat transfer pipe 8a, piping 20, heat transfer pipe 7a, and hot water outlet pipe 10) to boil the water. The heat exchanger 6 is provided at a position midway along the hot water supply side water passage, and transfers heat generated by combustion in the gas burner 4 to the water passing through the inside of the hot water supply side water passage. The heat exchanger 6 includes a primary heat exchanger 7 and a secondary heat exchanger 8. The primary heat exchanger 7 is disposed upstream of the combustion exhaust path of the gas burner 4 within the hot water supply combustion chamber 90. The secondary heat exchanger 8 is disposed downstream of the combustion exhaust path within the hot water supply combustion chamber 90.

In the hot water supply side circuit 2, the inlet pipe 12 is connected to the inlet of the secondary heat exchanger 8 in a configuration that supplies tap water. The inlet pipe 12 is provided with a thermistor 25 that detects the temperature of the water passing through the inlet pipe 12 (specifically, the water temperature at a position upstream of the heat exchanger and downstream of the water inlet 16 in the water passage pipe), and a water volume sensor 34 as a water volume detection unit that detects the water flow rate in the inlet pipe 12 (i.e., the amount of water flowing through the water passage pipe). The thermistor 25 corresponds to an example of an inlet water temperature detection unit, and has the function of detecting the temperature of water introduced from the outside. The heat transfer tube 8a of the secondary heat exchanger 8 is connected to the downstream side of the inlet pipe 12, and further downstream, a pipe 20 that connects the heat transfer tube 8a of the secondary heat exchanger 8 and the heat transfer tube 7a of the primary heat exchanger 7 is connected. The heat transfer tube 7a of the primary heat exchanger 7 is connected to the piping 20, and the outlet of the primary heat exchanger 7 is connected to the hot water outlet tube 10, which outputs the hot water heated by the primary heat exchanger 7. The outlet tube 10 is provided with a thermistor 26 that detects the temperature of the water in the outlet tube 10. In this configuration, the hot water supply side water passage and the bath side water passage correspond to an example of a "water passage pipe that passes water introduced from the outside". Of these, the hot water supply side water passage consisting of the water inlet tube 12, the heat transfer tube 8a, the piping 20, the heat transfer tube 7a, and the hot water outlet tube 10 corresponds to an example of a first water passage pipe and functions as a water passage provided in the hot water supply side circuit 2. On the other hand, the bath side water passage consisting of the drop tube 70 and the piping 66 corresponds to an example of a second water passage pipe and functions as a second water passage provided in the bath side circuit 3.

The heat exchanger 6 transfers heat generated by the gas burner 4 to water passing through a part of the hot water supply side water pipe. The heat exchanger 6 includes a primary heat exchanger 7 and a secondary heat exchanger 8. The heat exchanger 6 functions to recover sensible heat from the combustion exhaust gas by the primary heat exchanger 7, and then recover latent heat by the secondary heat exchanger 8. The primary heat exchanger 7 includes a heat transfer tube 7a that serves as a water passage in the primary heat exchanger 7, and transfers the combustion heat contained in the combustion exhaust gas generated by the gas burner 4 to the water passing through the heat transfer tube 7a, and exchanges heat by transferring the thermal energy of the sensible heat to the water. The secondary heat exchanger 8 includes a heat transfer tube 8a that serves as a water passage in the secondary heat exchanger 8, and transfers the combustion heat generated by the combustion exhaust gas generated by the gas burner 4 after passing through the primary heat exchanger 7 to the water passing through the heat transfer tube 8a, and exchanges heat by transferring the thermal energy of the latent heat to the water.

A bypass passage 14 is provided as a water passage that bypasses the water inlet pipe 12 and the hot water outlet pipe 10, and is configured as a water passage different from the heat exchanger 6. The bypass passage 14 is provided with a bypass valve 32 that can be switched between a closed state in which the water flow through the bypass passage 14 is blocked and an open state in which the opening is increased from the closed state. A water flow control valve 33 is provided upstream of the branch position where the bypass passage 14 is connected to the water inlet pipe 12. The water flow control valve 33 has a motor whose drive shaft rotation angle is controlled by instructions from the controller 22, and is configured to continuously change the water inlet pipe 12 to various openings between a closed state and a fully open state. In this configuration, the water flow control valve 33 functions to adjust the amount of water flowing through the water passage pipe.

The gas pipe 40 that supplies gas to the gas burners 4 is provided with a gas main solenoid valve 42, a hot water gas proportional control valve 44, and hot water switching solenoid valves 46, 46, etc. for each branch pipe to each gas burner 4 from the upstream side. In addition, a fan 48 that supplies combustion air to each gas burner 4 and gas burner 54 is provided below the hot water combustion chamber 90. A switching solenoid valve 53 is provided on the branch pipe from the gas pipe connected to the gas burner 54. The hot water gas proportional control valve 44 and hot water switching solenoid valve 46 function to adjust the amount of gas to the gas burner 4.

In the bath side circuit 3, the piping 66 includes a piping 67 for guiding water from the bathtub 60 side to the heat exchanger 56 side, a piping 68 for guiding water from the heat exchanger 56 side to the bathtub 60 side, and an intermediate piping 69 connected to the piping 67 and the piping 68 and passing through the heat exchanger 56. The piping 66 is configured as a path that communicates with the bathtub 60 at one end and the other end, and passes water from the bathtub 60 and returns it to the bathtub 60. The piping 66 is a path that circulates water drawn from the bathtub 60, for example, during reheating or boiling operation, by guiding it to the heat exchanger 56 through the piping 67, and water that has passed through the heat exchanger 56 by guiding it to the bathtub 60 through the piping 68. The gas burner 54 functions as a bath side burner, burning combustion gas to generate combustion exhaust. The heat exchanger 56 transfers heat generated by the gas burner 54 to water passing through a part of the bath side water pipe (specifically, water passing through the piping 66). The heat exchanger 56 includes a primary heat exchanger 57 and a secondary heat exchanger 58, and functions to transfer heat generated by the gas burner 54 to the water passing through the pipe 66.

The piping 67 is disposed between the bathtub 60 and the secondary heat exchanger 58, and is provided with a circulation pump 62 and a thermistor 64 (bath thermistor) that detects the temperature of the water passing through the piping 67. The thermistor 64 functions to detect the temperature of the water discharged from the bathtub 60 (i.e., the water temperature in the bathtub 60). The circulation pump 62 is a device that moves the water in the piping 66, and functions to draw in water from the bathtub 60 side and discharge the drawn water toward the heat exchanger 56 side.

The pipe 68 is disposed between the primary heat exchanger 57 and the bathtub 60. A drop pipe 70 branched off from the hot water outlet pipe 10 is connected to the pipe 68, and hot water supplied from the drop pipe 70 flows into the pipe 68. The drop pipe 70 is provided with a hot water supply solenoid valve 72 and a drop water volume sensor 74. By opening the hot water supply solenoid valve 72 provided on the drop pipe 70, hot water heated in the hot water supply side circuit 2 can be supplied to the bathtub 60. The drop water volume sensor 74 has the function of detecting the amount of water supplied to the bathtub 60 via the drop pipe 70.

The drop pipe 70 is a path that carries hot water from the hot water supply side water passage of the hot water supply side circuit 2 to the pipe 66 (circulation path) of the bath side circuit 3. The drop pipe 70 branches off from the hot water outlet pipe 10 and communicates with the pipe 67, and functions to guide the water heated by the heat exchanger 6 through the hot water supply side water passage to the bathtub 60.

2, the hot water supply device 1 is provided with a controller 22. As shown in FIG. 3, the controller 22 includes a control unit 22A configured as a known microcomputer or the like, a memory 22B configured as a known semiconductor memory or the like, and a communication unit 22C configured as an interface for communicating with the outside. The controller 22 is configured to be able to acquire signals from various sensors provided in the hot water supply side circuit 2 and the bath side circuit 3, and can control various actuators provided in the hot water supply side circuit 2 and the bath side circuit 3. In this configuration, the controller 22, the hot water supply solenoid valve 72, and the drop water volume sensor 74 correspond to an example of a supply unit, and function to supply water in the water supply pipe to the bathtub. Furthermore, the controller 22 corresponds to an example of a control unit, and controls the operation of the gas burners 4, 54 (burners) and at least a part of the above supply unit.

The controller 22 is also configured to be able to communicate with an external device provided outside the water heating apparatus 1 via a communication network such as the Internet, and is configured to be able to acquire information from the external device. In this configuration, the controller 22 corresponds to an example of an acquisition unit, and has a function of acquiring temperature-related information. The controller 22 also corresponds to an example of an outside air temperature information acquisition unit, and has a function of acquiring information related to the outside air temperature from outside the water heating apparatus 1.

As shown in FIG. 3, the multiple remote controllers 80 are arranged in a configuration that allows communication with the controller 22. In the example of FIG. 2 and FIG. 3, the multiple remote controllers 80 include a first remote controller 81 provided in the bathroom and a second remote controller 82 provided in a location other than the bathroom (e.g., the kitchen, etc.).

3, the first remote controller 81 includes a control unit 81A configured as a known microcomputer or the like, a display unit 81B configured as a liquid crystal display device or the like, an operation unit 81C having a plurality of known switches such as push buttons, a communication unit 81D that communicates with the controller 22 and the second remote controller 82, and an audio output unit 81E consisting of a speaker or the like that outputs audio. The operation unit 81C is made up of a plurality of operation units, and is used for input operations to instruct the bathtub 60 to be filled with water (input operations to instruct automatic filling and input operations to instruct energy-saving filling), input operations to schedule filling, input operations to switch the on/off state of the additional functions described above, and the like.

The second remote controller 82 is similar and includes a control unit 82A configured as a known microcomputer or the like, a display unit 82B configured as a liquid crystal display device or the like, an operation unit 82C having a plurality of known switches such as push buttons, a communication unit 82D for transmitting signals generated by the second remote controller 82 to the controller 22, and an audio output unit 82E consisting of a speaker or the like for outputting audio. The second remote controller 82 has the same configuration as the first remote controller 81, or a simplified configuration, and can be set in the same way as the first remote controller 81. The on and off states of both remote controllers 80 are linked. Settings made in either remote controller 80 are reflected in the other remote controller.

(Supply Control)
The controller 22 performs the supply control to the bathtub 60 in the flow shown in FIG. 4, for example. The supply control in FIG. 4 is started by the controller 22 when a predetermined mode is set in the hot water supply device 1 (specifically, the energy-saving hot water filling mode is set), and is repeatedly executed while the predetermined mode is set. For example, when a predetermined setting operation (for example, a predetermined pressing operation on one or more predetermined buttons) is performed on the first remote controller 81 or the second remote controller 82, the controller 22 sets the operation mode of the hot water supply device 1 to the predetermined mode (energy-saving hot water filling mode). Then, when the operation mode of the hot water supply device 1 is set to the predetermined mode (energy-saving hot water filling mode), the controller 22 starts executing the supply control in FIG. 4 after the setting. When the operation mode of the hot water supply device 1 is set to the predetermined mode (energy-saving hot water filling mode), the controller 22 repeatedly executes the supply control in FIG. 4. When a predetermined release condition is met (for example, when a condition for setting to another mode such as the automatic hot water filling mode is met), the controller 22 releases the predetermined mode (energy-saving hot water filling mode). When an operation is performed to instruct automatic filling of water to the first remote controller 81 or the second remote controller 82, the controller 22 sets the water heater 1 to the automatic filling mode. In this case, the controller 22 operates the water heater 1 in the automatic filling mode and controls it to perform a general automatic filling operation. When performing a general automatic filling operation, the controller 22 maintains the hot water supply solenoid valve 72 in an open state, burns the gas burner 4 to boil water in the hot water supply side circuit 2, and fills the bathtub 60 with a set amount of hot water boiled in the hot water supply side circuit 2 through the drop pipe 70 (communication pipe). In this way, in the representative example, the setting of the automatic filling mode and the setting of the energy-saving filling mode can be switched by the user's operation.

After the supply control of FIG. 4 is started, the controller 22 determines whether the non-heated supply condition is satisfied in step S1. The non-heated supply condition is a "condition indicating an increase in the water temperature in the water pipe" and is a predetermined condition. In the following representative example, the non-heated supply condition is a condition in which "a state in which the water in the water pipe is not supplied to the outside of the hot water heater 1 and the outside air temperature is equal to or higher than the threshold temperature continues for a predetermined period of time." The "state in which the water is not supplied to the outside" here refers to a state in which the water in the water pipe is not supplied to the outside of the hot water heater 1 from the hot water outlet pipe 10 and is not supplied to the bathtub 60. The controller 22 may continuously grasp the outside air temperature by intermittently acquiring the detection value of an outside air temperature thermistor (not shown). In this case, the outside air temperature thermistor may be arranged outside the housing 5, or may be arranged inside the housing 5 in a space into which air outside the housing flows. Alternatively, the controller 22 may intermittently obtain weather data including information on the outside temperature at the installation location of the controller 22 from an external site via a communication network such as the Internet, and continuously grasp the outside temperature. The above-mentioned predetermined time may be a fixed time determined in advance. Alternatively, the above-mentioned predetermined time may be determined corresponding to the outside temperature. For example, a plurality of relationships between the outside temperature and the predetermined time may be determined by an arithmetic expression or table that sets the above-mentioned predetermined time so that the higher the outside temperature (e.g., the average value of the outside temperature for a certain period of time recently), the shorter the above-mentioned predetermined time, and the controller 22 may set the predetermined time corresponding to the outside temperature by the above-mentioned arithmetic expression or table.

If the controller 22 determines in step S1 that the non-heated supply condition is satisfied, it performs a non-heated supply operation in step S2. The control performed by the controller 22 in step S2 is "control to cause the supply unit to supply water from the water supply pipe to the bathtub without causing the burner to burn." Specifically, the controller 22 opens the hot water supply solenoid valve 72 without causing the gas burners 4, 54 to burn, and then continues to open the hot water supply solenoid valve 72 until the drop water volume sensor 74 detects a predetermined "reference water volume." The "reference water volume" is set to a volume of water smaller than the volume of water that can be contained inside the bathtub 60. Specifically, the "reference water volume" is determined based on the first water volume, which is the water volume held by the first water pipe (the water inlet pipe 12, the heat transfer pipe 8a, the pipe 20, the heat transfer pipe 7a, and the hot water outlet pipe 10) described above, the second water volume, which is the water volume held by the second water pipe (the drop pipe 70 and the pipe 66) described above, and the third water volume, which is the water volume held by the third water pipe that is a pipe leading to the first water pipe and is provided outside the housing. The reference water volume may be a sum of the first water volume, the second water volume, and the third water volume. Alternatively, it may be a value obtained by multiplying this sum by a predetermined coefficient. Alternatively, it may be a value determined by an arithmetic expression or a table with the first water volume, the second water volume, and the third water volume as variables. The first water volume, the second water volume, and the third water volume may be predetermined design values (fixed values), or may be calculated by the controller 22.

When calculating the first, second, and third water volumes, the controller 22 may calculate the first, second, and third water volumes based on the operation of the hot water supply side circuit 2 and the bath side circuit 3. In this case, the controller 22 corresponds to an example of a water volume calculation unit and a third water volume calculation unit. For example, the controller 22 may calculate the sum of the first and second water volumes based on the time T1 from when the circulation pump 62 is operated until the thermistor of the return pipe detects a predetermined temperature change after supplying water from the hot water supply side circuit 2 to the bathtub 60 with hot water in the bathtub 60 and replacing the piping in the hot water supply device 1 with water, the supply volume W1 per unit time of the circulation pump 62, and the diameter D1 of the piping in the hot water supply device 1. In this example, a formula or table for calculating the sum of the first and second water volumes based on the time T1 (variable), the supply volume W1 (variable), and the diameter D1 (constant) is prepared in advance, and when the time T1 and the supply volume W1 are detected, the sum Wa of the first and second water volumes is calculated using the formula or table. Note that any method other than this method may be used as long as it is capable of estimating the sum of the first and second water volumes (the volume of water in the water supply pipe in the hot water supply device 1). For example, if the temperature of the thermistor 25 immediately after the start of the supply of hot water to the bathtub 60 without heating is set as the reference temperature, the amount of hot water supplied to the bathtub from the start of the supply of hot water to the bathtub without heating until the water temperature detected by the thermistor 65 reaches the reference temperature may be estimated as the sum of the first and second water volumes.

The controller 22 may calculate the third water volume W3 based on the time T3 from when the water heater 1 transitions from the non-discharge state to the discharge state until the temperature detected by the thermistor 25 (inlet water temperature detection unit) drops by a predetermined temperature, the amount of water discharge W2 from when the water heater 1 transitions from the non-discharge state to the discharge state until the temperature detected by the thermistor 25 (inlet water temperature detection unit) drops by a predetermined temperature, and the diameter D3 of the outer pipe 191 (third water pipe) connected to the water inlet 16. In this example, an arithmetic formula or table for calculating the third water volume Wb based on the time T3 (variable), the amount of water discharge W2 (variable), and the diameter D3 (constant) is prepared in advance, and when the time T3 and the amount of water discharge W2 are detected, the third water volume Wb can be calculated using the arithmetic formula or table. Alternatively, the third water amount may be defined as the amount of water supplied from the pipe 191 into the water inlet pipe 12 from the time when the supply of hot water from the water heater 1 begins until the temperature detected by the thermistor 25 (inlet water temperature detection unit) drops by a predetermined temperature.

Thus, in this configuration, the controller 22 repeatedly controls the supply unit to supply the "reference water volume" of water from the water pipe to the bathtub 60 without causing the gas burners 4, 54 to burn, each time the temperature-related information satisfies a predetermined condition (a condition indicating an increase in the water temperature in the water pipe) (i.e., each time the answer is Yes in step S1). Note that if the total amount of water supplied in one day by the repeated non-heated supply operations reaches a limit value (e.g., a set amount of hot water), the non-heated supply operation for that day may be restricted (prohibited) by preventing subsequent Yes answers in step S1.

If the controller 22 judges No in step S1 or after step S2, it judges in step S3 whether the energy-saving bath filling condition is satisfied. The energy-saving bath filling condition is, for example, "the first time a predetermined set time has arrived since the date was changed." The energy-saving bath filling condition is also called the energy-saving bath filling condition. If the energy-saving bath filling condition is satisfied (if the first time a predetermined set time has arrived since the date was changed), the condition is maintained until the processing of step S6 is completed, and when the processing of step S6 is completed, the condition is released. The set time is a predetermined time. In the representative example described below, the set time is determined based on the "reserved time," which is the scheduled time for completion of the bath filling. This reserved time is set to the input time, for example, in response to the user inputting time information by operating the first remote controller 81 or the second remote controller 82. The set time is then set to a time a predetermined time before the reserved time (for example, 30 minutes before). Note that the energy-saving water filling conditions described above are merely examples, and other conditions (for example, some special operation being performed) may also be used.

If the controller 22 determines in step S3 that the energy-saving filling conditions are not met, the determination in step S3 is No, and in this case, the control in FIG. 4 is terminated. When the control in FIG. 4 is terminated, the control in FIG. 4 is started again at short time intervals.

If the controller 22 determines in step S3 that the energy-saving water filling condition is met, the determination in step S3 is Yes, and in this case, the controller 22 checks the amount of stored water in step S4. When checking the amount of stored water in step S4, the controller 22 can regard the amount of water supplied in step S2 (if step S2 has been performed multiple times since the end of the previous reheating operation, the total amount of water supplied multiple times) as the amount of stored water. Alternatively, the amount of stored water may be checked using a water level sensor provided in the bathtub 60.

After step S4, the controller 22 performs an energy-saving water filling operation in step S5. The energy-saving water filling operation is also called an energy-saving water filling operation. When the controller 22 performs an energy-saving water filling operation in step S5, it calculates the supply amount (drop amount). The controller 22 sets the supply amount (drop amount) to a value obtained by subtracting the amount of stored water confirmed in step S4 from the preset hot water amount. The set hot water amount is, for example, a value that is predetermined in the water heater 1. The set hot water amount may be corrected or changed by the user. The controller 22 then operates the hot water supply side circuit 2 to combust the gas burner 4, while causing the above supply amount of hot water to drop into the bathtub 60 through the drop pipe 70 (communicating pipe). Specifically, the controller 22 executes control to open the hot water supply solenoid valve 72 provided in the drop pipe 70, and then supply hot water at a preset hot water supply temperature to the bathtub 60 through the drop pipe 70 (communicating pipe) until the amount of water detected by the drop water volume sensor 74 reaches the above-mentioned "supply amount." Then, when the amount of water detected by the drop water volume sensor 74 reaches the above-mentioned "supply amount," the controller executes control to close the hot water supply solenoid valve 72 and stop the supply of hot water from the hot water supply side circuit 2 to the bath side circuit 3.

After performing the energy-saving water filling operation (drop-in operation) in step S5, the controller 22 performs the reheating operation in step S6. The reheating operation can be performed by a known method, and operates the bath-side circuit 3 to circulate and heat the water in the bathtub 60, raising it to a predetermined set temperature. When the temperature of the water in the bathtub 60 reaches the set temperature, the controller 22 ends the reheating operation in step S6. After ending the reheating operation in step S6, the controller 22 ends the control in FIG. 4. While the controller 22 is set to the above-mentioned specified mode (energy-saving water filling mode), when the control in FIG. 4 is ended, the controller 22 starts the control in FIG. 4 again at short time intervals.

For example, in the representative example described above, the reserved time (the scheduled time for completion of filling the bath) is 17:00. The controller 22 is configured to set the set time to 30 minutes before the reserved time. In this case, when the above-mentioned specified mode (energy-saving filling mode) is set, the judgment in step S3 will be No during the period from when the date is changed to when the set time first arrives (i.e., the period from 0:00 to 16:30). Therefore, during this period, the non-heating supply operation in step S2 will be repeated every time it is determined in step S1 that the non-heating supply condition is met. After that, when the above period has elapsed and the set time (16:30) arrives, the processing in steps S4 to S6 is performed, and the above-mentioned energy-saving filling operation replenishes hot water up to the set amount and circulates and heats the water up to the set temperature. After the energy-saving filling operation is performed, the condition of "the first arrival of the set time after the date is changed" is not met until the end of the day, so the judgment in step S3 will be No.

The following description relates to an example of the effect of this configuration.
Water heater 1 can repeatedly supply water from the water pipe to bathtub 60 without causing the burner to combust, every time a predetermined condition indicating an increase in the water temperature in the water pipe is satisfied. Because water heater 1 supplies unheated water from the water pipe (without burning the burner) every time a condition indicating an increase in the water temperature in the water pipe is satisfied, water with an increased temperature can be repeatedly supplied to bathtub 60 without consuming gas energy, and the bathtub can be filled while reducing gas energy.

The water heater 1 can repeatedly supply water from the water pipe to the bathtub 60 without causing the burner to burn, whenever the condition that "a state in which the water in the water pipe is not supplied to the outside and the outside air temperature is equal to or higher than the threshold temperature continues for a predetermined period of time or more" is satisfied. After reliably confirming that the water pipe has been warmed by the outside air temperature for a predetermined period of time or more, the water heater 1 can supply water from the water pipe to the bathtub 60 without heating (without burning the burner). This makes it possible to prevent the unheated supply operation from being performed when the water temperature is low, making it easier to repeatedly supply warm water.

More specifically, the controller 22 (control unit) controls the supply unit to supply a standard amount of water from the water pipe to the bathtub 60 without causing the burner to burn, and this is repeated every time the temperature-related information satisfies a specified temperature condition. In this way, the water heater 1 supplies a standard amount of water from the water pipe every time the specified temperature condition is satisfied, making it easier to suppress variations in the temperature of the water supplied when the condition is met.

The hot water supply device 1 has a housing, a hot water supply side circuit 2 including the heat exchanger, and a bath side circuit 3 having a connecting pipe 70 (piping) branching off from the hot water supply side circuit 2. The hot water supply side circuit 2 and the bath side circuit 3 are housed within the housing. The water passage pipes include a first water passage pipe provided in the hot water supply side circuit 2 and a second water passage pipe provided in the bath side circuit 3. The reference water volume is determined based on a first water volume which is the water volume held by the first water passage pipe, a second water volume which is the water volume held by the second water passage pipe, and a third water volume which is the water volume held by a third water passage pipe provided on the outside of the housing and connected to the first water passage pipe. This hot water supply device 1 can determine the amount of water to be supplied (reference water amount) when the conditions are met based on the amount of water held in the water pipes (first water pipe, second water pipe, third water pipe) at predetermined positions, making it easier to stabilize the temperature of the water supplied when the conditions are met.

The hot water supply device 1 has a first water volume calculation unit that calculates the first water volume based on the operation of the hot water supply side circuit 2 and the bath side circuit 3, making it easy to reduce costs and increase versatility.

The water heater 1 has an inlet water temperature detection unit that detects the temperature of water introduced from outside, and a third water amount calculation unit that calculates a third water amount based on the time from when the water heater 1 transitions from a non-hot water discharging state to a hot water discharging state until the temperature detected by the inlet water temperature detection unit drops by a predetermined temperature, so that it is possible to determine how much water present outside the water heater 1 should be used based on the inlet water temperature.

<Other embodiments>
The present disclosure is not limited to the embodiments described above and in the drawings. For example, the features of the above or later described embodiments can be combined in any combination within a range that does not contradict. Furthermore, any feature of the above or later described embodiments may be omitted unless it is clearly stated as essential. Furthermore, the above-mentioned embodiment may be modified as follows.

In the above embodiment, an example was shown in which the controller 22 repeatedly performs the control of step S2 (controlling the supply unit to supply the "reference water volume" of water from the water pipe to the bathtub without causing the gas burners 4, 54 to burn) each time the temperature-related information satisfies a predetermined condition, but the volume supplied in the operation of step S2 does not have to be the "reference water volume." For example, the volume of water may change each time it is supplied. For example, the supply operation may continue as long as the temperature of the supplied water is equal to or higher than a certain temperature after the operation of step S2 is started, and the supply operation may be stopped when the temperature falls below the certain temperature.

In the above description of the embodiment, the judgment condition in step S1 of the first embodiment, "the state in which the water in the water pipe is not supplied to the outside and the outside air temperature is equal to or higher than the threshold temperature continues for a predetermined time or more," is given as an example of the "predetermined condition in which the temperature-related information indicates an increase in the water temperature in the water pipe," but this example is not limited to this. For example, "the inlet water temperature is equal to or higher than a predetermined value" may be the "predetermined condition in which the temperature-related information indicates an increase in the water temperature in the water pipe." Specifically, for example, if the detected temperature of thermistors 25, 64, and 65 (e.g., the inlet water temperature detected by thermistor 25) is equal to or higher than a predetermined value, the judgment in step SS1 may be Yes. Such a judgment process may be performed instead of the judgment process in step S1 of the first embodiment, and the judgment in step S1 may be Yes not only in the "condition for judging Yes in step S1 in the first embodiment" but also in the case where the detected temperature of thermistors 25, 64, and 65 (e.g., the inlet water temperature detected by thermistor 25) is equal to or higher than a predetermined value. In either case, if the detected temperature of any of the thermistors 25, 25, 64, and 65 is equal to or higher than a predetermined value, the answer may be Yes in step S1; if the detected temperatures of all of the thermistors 25, 25, 64, and 65 are equal to or higher than a predetermined value, the answer may be Yes in step SS1; or if the average detected temperature of thermistors 25, 25, 64, and 65 is equal to or higher than a predetermined value, the answer may be Yes in step SS1.

The non-heating supply condition may include conditions other than those related to temperature. For example, the non-heating supply condition may include information about a time period. For example, the non-heating condition may be met when "temperature-related information satisfies a specified condition between 12:00 and 18:00."

Although the outside air temperature has been given as an example of information on factors that affect the water temperature in the water pipe, it could also be, for example, the temperature of a specific part in the water heater.

In the above embodiment, the non-heated supply condition was that "the outside air temperature remains above the threshold temperature for a predetermined period of time without the water in the water pipe being supplied to the outside," but it may also be that "the outside air temperature remains above the threshold temperature after a certain period of time has elapsed since the previous operation of supplying hot water to the outside of the water heater."

It should be noted that the embodiments disclosed herein are illustrative in all respects and should not be considered restrictive. The scope of the present invention is not limited to the embodiments disclosed herein, but is intended to include all modifications within the scope of the claims or within the scope equivalent to the claims.

1...Hot water supply device 2...Hot water supply side circuit 3...Bath side circuit 4, 54...Gas burner 5...Housing 6, 56...Heat exchanger 7a, 8a...Heat transfer pipe (water pipe, first water pipe)
10...Hot water pipe (water pipe, first water pipe)
12... Water inlet pipe (water pipe, first water pipe)
20... Piping (water pipe, first water pipe)
22...Controller (supply unit, control unit, acquisition unit, outside air temperature information acquisition unit, first water volume calculation unit, third water volume calculation unit)
25...Thermistor (inlet water temperature detection section)
60...bathtub 66...piping (water pipe, second water pipe)
70...Drop-in pipe (water pipe, second water pipe)
72...Hot water supply solenoid valve (supply section)
191...Piping (third water pipe)

Claims (5)

A water pipe through which water introduced from the outside passes;
A burner for burning gas;
a heat exchanger that transfers heat generated by the burner to water passing through a portion of the water pipe;
having
A hot water supply device that at least performs an operation of supplying water heated by the heat exchanger to a bathtub,
an acquisition unit that acquires temperature-related information including information on the water temperature in the water pipe or information on factors that affect the water temperature in the water pipe;
A supply unit that supplies water in the water pipe to the bathtub;
A control unit that controls the operation of the burner and the supply unit;
having
The acquisition unit intermittently acquires weather data including information on outside temperature from the outside via the Internet,
the temperature-related information includes information about the outside air temperature;
the control unit repeatedly controls the supply unit to supply water from the water pipe to the bathtub without causing the burner to perform combustion each time the temperature-related information satisfies a predetermined condition indicating an increase in the water temperature in the water pipe;
The predetermined condition includes a condition that a state in which the outside air temperature is equal to or higher than a threshold temperature while the water in the water pipe is not supplied to the outside continues for a predetermined period of time or more.
Water heating equipment. The hot water supply device according to claim 1, wherein the control unit repeatedly controls the supply unit to supply a standard amount of water from the water pipe to the bathtub without causing the burner to perform combustion each time the temperature-related information satisfies the specified condition . A water pipe through which water introduced from the outside passes;
A burner for burning gas;
a heat exchanger that transfers heat generated by the burner to water passing through a portion of the water pipe;
having
A hot water supply device that at least performs an operation of supplying water heated by the heat exchanger to a bathtub,
an acquisition unit that acquires temperature-related information including information on the water temperature in the water pipe or information on factors that affect the water temperature in the water pipe;
A supply unit that supplies water in the water pipe to the bathtub;
A control unit that controls the operation of the burner and the supply unit;
A housing and
A hot water supply side circuit including the heat exchanger;
A bath side circuit having a piping branched from the hot water supply side circuit;
having
The hot water supply side circuit and the bath side circuit are housed in the housing,
the control unit repeatedly controls the supply unit to supply a reference amount of water from the water pipe to the bathtub without causing the burner to perform combustion each time the temperature-related information satisfies a predetermined condition indicating an increase in the water temperature in the water pipe;
The water pipe includes a first water pipe provided in the hot water supply side circuit and a second water pipe provided in the bath side circuit,
the reference water volume is determined based on a first water volume that is a water volume held in the first water pipe, a second water volume that is a water volume held in the second water pipe, and a third water volume that is a water volume held in a third water pipe that is a pipe communicating with the first water pipe and is provided outside the housing;
a water volume calculation unit that calculates the sum of the first water volume and the second water volume based on operations of the hot water supply side circuit and the bath side circuit . an inlet water temperature detection unit that detects the temperature of water introduced from the outside;
a third water amount calculation unit that calculates the third water amount based on a time from when the hot water supply apparatus transitions from a non-hot water supply state to a hot water supply state until the temperature detected by the inlet water temperature detection unit drops by a predetermined temperature;
have
The water heater according to claim 3 . A water pipe through which water introduced from the outside passes;
A burner for burning gas;
a heat exchanger that transfers heat generated by the burner to water passing through a portion of the water pipe;
having
A hot water supply device that at least performs an operation of supplying water heated by the heat exchanger to a bathtub,
an acquisition unit that acquires temperature-related information including information on the water temperature in the water pipe or information on factors that affect the water temperature in the water pipe;
A supply unit that supplies water in the water pipe to the bathtub;
A control unit that controls the operation of the burner and the supply unit;
A housing and
A hot water supply side circuit including the heat exchanger;
A bath side circuit having a piping branched from the hot water supply side circuit;
having
the control unit repeatedly controls the supply unit to supply a reference amount of water from the water pipe to the bathtub without causing the burner to perform combustion each time the temperature-related information satisfies a predetermined condition indicating an increase in the water temperature in the water pipe;
The hot water supply side circuit and the bath side circuit are housed in the housing,
The water pipe includes a first water pipe provided in the hot water supply side circuit and a second water pipe provided in the bath side circuit,
the reference water volume is determined based on a first water volume that is a water volume held in the first water pipe, a second water volume that is a water volume held in the second water pipe, and a third water volume that is a water volume held in a third water pipe that is a pipe communicating with the first water pipe and is provided outside the housing;
Furthermore,
an inlet water temperature detection unit that detects the temperature of water introduced from the outside;
a third water amount calculation unit that calculates the third water amount based on a time from when the hot water supply apparatus transitions from a non-hot water supply state to a hot water supply state until the temperature detected by the inlet water temperature detection unit drops by a predetermined temperature;
A water heating device having the above structure.

Images