JP6848449B2 - Hot water heater - Google Patents

Description

The present invention relates to a hot water supply device.

Conventionally, for example, Patent Document 1 discloses a technique relating to a water heater having a reheating function provided with a water level sensor for detecting the water level of a bathtub. The water heater with a reheating function is equipped with a bath-side water supply circuit that circulates bathtub water and a heat exchanger installed in the bath-side water supply circuit. In the reheating operation, the bath water is circulated to the bath water supply circuit and the heat exchanger. Therefore, dirt such as sebum or keratin in the bathtub water adheres to the inner surface of the bath side water supply circuit and the heat exchanger. The attached dirt can cause a decrease in heat exchange efficiency or poor circulation due to clogging of piping.

In the water heater of Patent Document 1, when the water level sensor detects a drop in the water level of the bathtub, fine bubbles are introduced into the water supply circuit on the bathtub side. As a result, while the bathtub water is being drained, the pipes and heat exchangers that make up the bath side water supply circuit are automatically cleaned.

Japanese Unexamined Patent Publication No. 2009-293884

In the above-mentioned conventional technique, in order to distinguish between a water level drop due to the user scraping out bathtub water and a water level drop due to drainage from which the bathtub plug has been removed, a lower limit threshold for the water level drop rate for determining drainage is determined. There is. Therefore, if there is a factor that the drainage speed is slow, such as the construction condition such as the bathtub shape and the pipe diameter, or the drainage port is clogged, the drainage may not be determined. As a result, a hot water supply device that automatically cleans pipes and the like during drainage may not have an opportunity to perform the cleaning operation.

The present invention has been made to solve the above-mentioned problems, and is an opportunity for a cleaning operation even when the drainage speed is slow in a hot water supply device that performs a cleaning operation of a circulation circuit for circulating water in a bathtub during drainage. It is an object of the present invention to provide a hot water supply device capable of obtaining.

The hot water supply device according to the present invention includes a water level detecting means for detecting the water level of the bathtub, a circulation circuit for circulating the water in the bathtub, a circulation pump for circulating water in the circulation circuit, and circulation when the circulation pump is driven. In a hot water supply device including a water flow detecting means for detecting the water flow of the circuit, a cleaning means for cleaning the circulation circuit with air bubbles, and a control unit for controlling the circulation pump and the cleaning means, the control unit detects the water level. Based on the water level detected by the means, an index value that correlates with the water level drop time per unit height of the bathtub is calculated, and the index value is the first threshold and the second threshold that the water level drop time is larger than the first threshold. If the water level in the bathtub is lower than the judgment reference water level, the cleaning operation is performed, and the index value is between the second threshold and the third threshold in which the water level drop time is larger than the second threshold. and if the water level of the tub is lower than the determination reference water level, have rows cleaning operation when the water flow is not detected by the water flow detection means, when the index value is greater value drawdown time than the third threshold value, cleaning It is configured to prohibit operation .
Further, the hot water supply device according to the present invention is when the water level detecting means for detecting the water level of the bathtub, the circulation circuit for circulating the water in the bathtub, the circulation pump for circulating water in the circulation circuit, and the circulation pump are driven. In a hot water supply device including a water flow detecting means for detecting the water flow of the circulation circuit, a cleaning means for cleaning the circulation circuit with air bubbles, and a control unit for controlling the circulation pump and the cleaning means, the control unit is Based on the water level detected by the water level detecting means, an index value that correlates with the water level drop time per unit height of the bathtub is calculated, and the index value is the first threshold and the water level drop time is larger than the first threshold. If the value is between the thresholds and the water level in the bathtub is lower than the judgment reference water level, a cleaning operation is performed and the index value is between the second threshold and the third threshold in which the water level drop time is larger than the second threshold. If the water level in the bathtub is lower than the judgment reference water level, the cleaning operation is performed when the water flow is not detected by the water flow detecting means, and the index value is a value in which the water level drop time is larger than the third threshold value. It is configured to prohibit the cleaning operation.

According to the hot water supply device of the present invention, it is possible to provide a hot water supply device capable of obtaining an opportunity for a cleaning operation even when the drainage speed is slow.

It is a block diagram of the hot water storage type water heater as a hot water supply device in Embodiment 1. FIG. It is a figure for demonstrating the configuration of the remote controller of Embodiment 1. FIG. It is a circuit block diagram at the time of boiling operation of the hot water storage type water heater of Embodiment 1. FIG. It is a circuit block diagram at the time of the 1st cleaning operation using the circulation fine bubble generator of the hot water storage type water heater of Embodiment 1. FIG. It is a circuit block diagram at the time of the 2nd cleaning operation using the fine bubble generator for water injection of the hot water storage type water heater of Embodiment 1. FIG. It is a flowchart of the control routine executed in the hot water storage type water heater of Embodiment 1.

Hereinafter, embodiments will be described with reference to the drawings. The elements common to each figure are designated by the same reference numerals, and duplicate description will be omitted.

Embodiment 1.
FIG. 1 is a configuration diagram of a hot water storage type water heater 100 as a hot water supply device according to the first embodiment. The hot water storage type water heater 100 shown in FIG. 1 includes a hot water storage tank unit 1 and a heat pump unit 60 configured to utilize a heat pump cycle. The two units 1 and 60 are connected by a heat pump inlet pipe 41 and a heat pump outlet pipe 42. Further, the hot water storage tank unit 1 has a built-in control unit 70. The operation of various valves, pumps, etc. included in the hot water storage tank unit 1 and the heat pump unit 60 is controlled by the control unit 70 connected to them via wiring. Hereinafter, each component of the hot water storage type water heater 100 will be described.

The heat pump unit 60 functions as a heating means for heating the low-temperature water led from the hot water storage tank unit 1. The heat pump unit 60 constitutes a heat pump cycle by connecting a compressor 61, a heating heat exchanger 62, an expansion valve 63, and an air heat exchanger 64 in an annular shape by a refrigerant circulation pipe 65. The boiling heat exchanger 62 is for exchanging heat between the refrigerant flowing through the refrigerant circulation pipe 65 constituting the heat pump cycle and the low-temperature water led from the hot water storage tank unit 1. Further, the HP outlet side thermistor 66 is a temperature sensor for detecting the temperature of the high temperature water heated by the boiling heat exchanger 62, and is provided in the heat pump outlet pipe 42. In order to obtain high temperature water in the heat pump unit 60, it is preferable that the heat pump cycle uses carbon dioxide as a refrigerant and operates at a pressure exceeding the critical pressure.

On the other hand, the hot water storage tank unit 1 contains the following various parts and pipes. The hot water storage tank 10 is for storing hot water. A water supply pipe 2 for supplying city water is connected to the lower part of the hot water storage tank 10. A first tank upper pipe 43 and a second tank upper pipe 44 are connected to the upper part of the hot water storage tank 10. A hot water supply pipe 3 for supplying the stored hot water to the outside of the water heater is connected in the middle of the second tank upper pipe 44. High-temperature water heated by the heat pump unit 60 flows into the hot water storage tank 10 from the upper part of the tank, and low-temperature water flows into the hot water storage tank 10 from the lower part of the tank through the water supply pipe 2. Hot water is stored so that there is a temperature difference at the bottom. Further, residual hot water thermistors 11 and 12 for detecting the temperature distribution of hot water in the hot water storage tank 10 are attached to the upper part and the lower part of the surface of the hot water storage tank 10, respectively. Based on the temperature distribution acquired by these residual hot water thermistors 11 and 12, the amount of residual hot water in the hot water storage tank 10 is grasped, and the start and stop of the boiling operation of the hot water in the hot water storage tank 10 by the heat pump unit 60 is controlled. Will be done.

Further, a heat source pump 21 and a user-side heat exchanger 22 are built in the hot water storage tank unit 1. The heat source pump 21 is a pump for circulating hot water to various pipes described later in the hot water storage tank unit 1. The user-side heat exchanger 22 is a heat exchanger for heating the water to be heated on the secondary side by using the high-temperature water supplied from the hot water storage tank 10 or the heat pump unit 60. In this embodiment, a bath circulation circuit 51 for circulating water in the bathtub 50 is provided as a configuration on the secondary side of the user side heat exchanger 22. The bath circulation circuit 51 is composed of a bath return pipe 56 and a bath return pipe 57. The bathtub return pipe 56 connects the bathtub adapter 80 of the bathtub 50 and the inlet side of the user side heat exchanger 22. Further, the bathtub adapter 57 connects the outlet side of the user side heat exchanger 22 and the bathtub adapter 80. A bathtub circulation pump 52 for circulating bathtub water and a bathtub outlet side thermista 53 for detecting the temperature of bathtub water discharged from the bathtub 50 are installed in the middle of the bathtub return pipe 56, respectively. Further, in the middle of the bath return pipe 56, a flow switch 58 as a water flow detecting means for detecting the presence or absence of water flow in the bath circulation circuit 51 and a water level sensor 59 as a water level detecting means for detecting the water level of the bathtub 50 are provided. Each is installed.

Further, the hot water storage tank unit 1 has a bath hot water supply pipe 34 and an electromagnetic valve 35. The bath hot water supply pipe 34 connects the connection portion between the second tank upper pipe 44 and the hot water supply pipe 3 and the bath return pipe 56 of the bath circulation circuit 51. The solenoid valve 35 is arranged in the middle of the bath hot water supply pipe 34.

A fine bubble generator 55 for water injection is installed in the middle of the bath hot water supply pipe 34. The water injection fine bubble generator 55 is a device that functions as a cleaning means for introducing fine bubbles into the bathtub 50 to clean the inside of the pipe. Further, a circulation fine bubble generator 54 is installed in the bath return pipe 56 of the bath circulation circuit 51. The circulation fine bubble generator 54 is a device that functions as a cleaning means for introducing fine bubbles to clean the inside of the pipe when the bath water is circulated. The water injection fine bubble generator 55 and the circulation fine bubble generator 54 can adopt a known structure for generating fine bubbles.

Next, the valves and pipes included in the hot water storage tank unit 1 will be described. The hot water storage tank unit 1 has a first three-way valve 31, a second three-way valve 32, and a four-way valve 33. The first three-way valve 31 and the second three-way valve 32 are flow path switching means having two inlets, a port and b port, for hot water to flow in, and a c port, which is one outlet for hot water to flow out. The first three-way valve 31 and the second three-way valve 32 are configured so that the hot water path can be switched so that hot water flows in from either the a port or the b port. The four-way valve 33 is a flow path switching means having two inlets, b port and c port, from which hot water flows in, and a port and d port, which are two outlets from which hot water flows out. The four-way valve 33 is configured so that the flow path form can be switched between the three paths, that is, the ca path, the cd path, and the ba path.

Further, the hot water storage tank unit 1 includes a tank lower pipe 40, a heat pump inlet pipe 41, a heat pump outlet pipe 42, a first tank upper pipe 43, a second tank upper pipe 44, a tank return pipe 45, and heat exchange on the user side. It has a vessel primary side inlet pipe 46, a user side heat exchanger primary side outlet pipe 47, a bypass pipe 48, and a tank upper return pipe 49.

More specifically, the tank lower pipe 40 is a flow path connecting the lower part of the hot water storage tank 10 and the a port of the second three-way valve 32. Further, the heat pump inlet pipe 41 is a flow path connecting the c port of the second three-way valve 32 and the inlet side of the heat pump unit 60. Further, the heat pump outlet pipe 42 is a flow path connecting the outlet side of the heat pump unit 60 and the c port of the four-way valve 33. Further, the tank upper return pipe 49 is a flow path connecting the d port of the four-way valve 33 and the b port of the first three-way valve 31. The first tank upper pipe 43 is a flow path connecting the upper part of the hot water storage tank 10 and the a port of the first three-way valve 31. The second tank upper pipe 44 is a flow path connecting the upper part of the hot water storage tank 10 and the middle of the tank upper part return pipe 49. The tank return pipe 45 is a flow path that connects the a port of the four-way valve 33 and the return port provided between the central portion and the lower portion of the hot water storage tank 10. Further, the utilization side heat exchanger primary side inlet pipe 46 is a flow path connecting the c port of the first three-way valve 31 and the primary side inlet of the utilization side heat exchanger 22. Further, the utilization side heat exchanger primary side outlet pipe 47 is a flow path connecting the primary side outlet of the utilization side heat exchanger 22 and the b port of the second three-way valve 32. Further, the bypass pipe 48 is a flow path connecting the portion of the heat pump inlet pipe 41 on the outlet side of the heat source pump 21 and the b port of the four-way valve 33. The heat source pump 21 is installed between the connection portion with the bypass pipe 48 on the heat pump inlet pipe 41 and the second three-way valve 32.

The hot water storage type water heater 100 of the first embodiment includes a remote controller 71. The remote controller 71 is installed in, for example, a bathroom or a kitchen, and is connected to the control unit 70 via a communication line. FIG. 2 is a diagram for explaining the configuration of the remote controller according to the first embodiment. As shown in this figure, the remote controller 71 is provided with a display unit 72, an operation unit 73, and an audio output unit 74. The display unit 72 is for displaying various states of the hot water storage type water heater 100, and is composed of, for example, a liquid crystal display. The operation unit 73 is for operating various controls of the hot water storage type water heater 100, and is composed of a plurality of buttons. The voice output unit 74 is for notifying various states of the hot water storage type water heater 100 by voice, and is composed of a speaker. By operating the operation unit 73, the user can perform a boiling operation, a setting related to a cleaning operation by the water injection fine bubble generator 55 or a circulation fine bubble generator 54, an operation start instruction, and the like, which will be described later. ..

In the hot water storage type water heater 100 of the first embodiment, the first three-way valve 31, the second three-way valve 32 and the four-way valve 33 are controlled according to the operating conditions shown in FIGS. 3 to 5 below to control the hot water storage tank unit 1 The flow path of the hot water inside is switched and used. FIG. 3 is a circuit configuration diagram of the hot water storage type water heater 100 of the first embodiment during boiling operation. The control unit 70 has a function of executing a boiling operation. The boiling operation referred to here is an operation of boiling water in the hot water storage tank 10 by using the heat pump unit 60. During this boiling operation, the second three-way valve 32 is controlled so that the a port and the c port communicate with each other and the b port is closed. As a result, the tank lower pipe 40 and the heat pump inlet pipe 41 communicate with each other, and the flow path from the user side heat exchanger 22 is cut off by closing the user side heat exchanger primary side outlet pipe 47 side. Further, during the boiling operation, the four-way valve 33 is controlled so that the c port and the d port communicate with each other and the a port and the b port are closed. As a result, the heat pump outlet pipe 42 and the tank upper part return pipe 49 communicate with each other, and the tank return pipe 45 side is closed to block the flow path to the lower part of the hot water storage tank 10. Further, during the boiling operation, the first three-way valve 31 is controlled so that the a port and the c port communicate with each other and the b port is closed. As a result, the first tank upper pipe 43 and the utilization side heat exchanger primary side inlet pipe 46 communicate with each other, and the tank upper return pipe 49 side is closed to cut off the flow path to the utilization side heat exchanger 22. ..

The boiling operation is executed by starting the operation of the heat source pump 21 and the heat pump unit 60 in a state where the first three-way valve 31, the second three-way valve 32, and the four-way valve 33 are controlled as described above. As a result, the low-temperature water flowing out from the lower part of the hot water storage tank 10 is guided to the heat pump unit 60 via the tank lower pipe 40, the second three-way valve 32, the heat source pump 21, and the heat pump inlet pipe 41. Then, the low-temperature water that has flowed into the heat pump unit 60 is heated by the boiling heat exchanger 62 to become high-temperature water. The heated high-temperature water flows into and is accumulated in the hot water storage tank 10 from the upper part of the hot water storage tank 10 via the heat pump outlet pipe 42, the four-way valve 33, the tank upper return pipe 49 and the second tank upper pipe 44. To. By executing such a boiling operation, high-temperature water is stored from the upper layer inside the hot water storage tank 10, and the high-temperature water layer gradually becomes thicker.

In the hot water storage type water heater 100 of the first embodiment, a cleaning operation for cleaning the bath circulation circuit 51 is automatically performed during the drainage of the water in the bathtub 50 from the bathtub plug. FIG. 4 is a circuit configuration diagram during the first cleaning operation using the circulation fine bubble generator 54 of the hot water storage type water heater 100 of the first embodiment. The control unit 70 has a function of executing the first cleaning operation. The first cleaning operation referred to here is an operation of circulating bath water containing fine bubbles in the bath circulation circuit 51 to clean the inside of the pipe. This first cleaning operation is started by operating the circulation fine bubble generator 54 and operating the bath circulation pump 52 when the conditions described later are satisfied. During the execution of the first cleaning operation, the bathtub water stretched in the bathtub 50 circulates in the bath circulation circuit 51. At this time, the fine bubbles generated by the circulation fine bubble generator 54 are introduced into the bath water in the bath circulation circuit 51. As a result, fine bubbles circulate in the bath circulation circuit 51 and the bathtub 50, so that the inside of the pipe and the wall surface of the bathtub 50 are cleaned.

Further, FIG. 5 is a circuit configuration diagram during a second cleaning operation using the water injection fine bubble generator 55 of the hot water storage type water heater 100 of the first embodiment. The control unit 70 has a function of executing the second cleaning operation. The second cleaning operation referred to here is an operation in which water containing fine bubbles is circulated to the bathtub 50 via the bath circulation circuit 51 to clean the inside of the pipe. This second cleaning operation is started by operating the water injection fine bubble generator 55 and opening the solenoid valve 35 when the conditions described later are satisfied. During the execution of the second cleaning operation, the hot water in the hot water storage tank is injected from the second tank upper pipe 44 and the bath hot water supply pipe 34 to the bathtub 50 via the bath circulation circuit 51. At this time, the fine bubbles generated by the circulation fine bubble generator 54 are introduced into the water flowing through the bath hot water supply pipe 34. As a result, water containing fine bubbles flows through the bath hot water supply pipe 34 and the bath circulation circuit 51 and is supplied into the bathtub 50, so that the inside of the pipe and the wall surface of the bathtub 50 are washed.

Next, the characteristic operation of the hot water storage type water heater 100 of the first embodiment will be described. In the hot water storage type water heater 100 of the first embodiment, a drainage determination is performed to determine that the bathtub water stretched in the bathtub 50 is being drained. In a state where the bathtub water is filled in the bathtub 50, for example, when the bathtub plug is pulled out by the user, the bathtub 50 is in a drained state. The drainage determination is a control in which the control unit 70 determines the drainage state of the bathtub 50. In the drainage determination, the time required for the water level to drop per unit height of the bathtub 50 (hereinafter, simply referred to as “water level drop time”) is used as an index value. The index value used for the wastewater determination is not limited to the water level drop time, and other index values having a correlation with the water level drop time, such as the water level drop rate, may be used.

In general, the water level drop time in the case of scraping out the bathtub water by the user or pumping up the bathtub water in the washing machine is longer than the water level drop time in the drained state of the bathtub 50. On the other hand, the water level drop time when the user takes a bath is smaller than the water level drop time in the drainage state of the bathtub 50. In the drainage determination, paying attention to these points, the drainage state of the bathtub 50 is determined by distinguishing it from other states.

However, even when the bathtub water is being drained, it is assumed that the water level drop time is as large as the pumping of the bathtub water, such as the shape of the bathtub, the construction state such as the pipe diameter, or the clogging of the drain port. In such a case, it is assumed that the drainage state is not determined even though the bathtub water is being drained. In this case, it is not possible to obtain an opportunity to perform a cleaning operation that is automatically performed during drainage.

Therefore, in the hot water storage type water heater 100 of the present embodiment, the chances of carrying out the washing operation are increased by executing the drainage determination and the washing operation according to the following flowchart. Hereinafter, specific processing of control executed by the control unit 70 will be described with reference to the flowchart.

FIG. 6 is a flowchart of a control routine executed in the hot water storage type water heater of the first embodiment. In step S1 of the control routine shown in FIG. 6, the water level drop time Ts (for example, 5 seconds) required for the water level of the bathtub 50 to drop by a unit height (1 cm) is measured based on the detection signal of the water level sensor 59. ..

In the next step S2, it is determined whether or not the water level drop time Ts measured in step S1 is a value equal to or higher than the first threshold value A which is a reference for drainage determination and equal to or lower than the second threshold value B which is larger than the first threshold value A. To. The first threshold value A is a threshold value for excluding a drop in water level due to bathing by a bather, and a preset value (for example, 1 second) is used. The second threshold value B is a threshold value for excluding a drop in the water level due to the user scooping out the bathtub water or pumping the bathtub water by the pump of the washing machine, and a preset value (for example, 20 seconds) is used. Will be done. The first threshold value A and the second threshold value B may be input by the user from the operation unit 73 of the remote controller 71 according to the specifications of the device, the construction state, or the like.

If, as a result of the determination in step S2, the establishment of A ≦ Ts ≦ B is confirmed, it is determined that the water is being drained, and the process proceeds to the next step S3. On the other hand, if the determination in step S2 is not established (for example, Ts = 60 seconds), it is determined that there is a high possibility that the water is not being drained, and the process proceeds to step S6.

In step S3, the water level X in the bathtub is detected from the detection signal of the water level sensor 59. In the next step S4, it is determined whether the water level X in the bathtub is lower than the determination reference water level Y. When the water level in the bathtub is high, the possibility of taking a bath or taking a bath again cannot be ruled out. As the determination reference water level Y here, a preset value is used as a threshold value of the water level for determining that the person is not in the bath.

If, as a result of the determination in step S4, the establishment of X <Y is not recognized, the process returns to the process of step S1 again to prohibit the cleaning operation, and the process of this routine is executed from the beginning. On the other hand, if the determination in step S4 is confirmed, it can be determined that the bathtub 50 is being drained and not being bathed. In this case, the process proceeds to the next step S5, and the automatic cleaning operation is started. Here, specifically, the first cleaning operation of operating the circulation fine bubble generator 54 and operating the bath circulation pump 52 is started. When the automatic cleaning operation is started, this routine is terminated.

Further, in step S6, it is determined whether or not the water level drop time Ts measured in step S1 is a value equal to or less than the third threshold value C, which is larger than the second threshold value B and larger than the second threshold value B. As the third threshold value C, a preset value (for example, 30 seconds) is used as a threshold value for determining drainage when the drainage speed is slow, such as clogging of the drain port. The third threshold value C may be input by the user from the operation unit 73 of the remote controller 71 according to the specifications of the device, the construction state, or the like.

If B <Ts ≦ C is confirmed as a result of the determination in step S6, it is determined that there is a possibility of drainage, and the process proceeds to the next step S7. On the other hand, when the determination in step S6 is not established (for example, Ts = 60 seconds or 0.5 seconds), it is determined that the water is not being drained. In this case, the process returns to the process of step S1 again to prohibit the cleaning operation, and the process of this routine is executed from the beginning.

In step S7, the water level X in the bathtub is detected from the detection signal of the water level sensor 59. In the next step S8, it is determined whether the water level X in the bathtub is lower than the determination reference water level Y. Here, the same process as in step S4 is executed. As a result of the determination in step S8, if the establishment of X <Y is not confirmed, it is determined that there is a possibility that the bathtub water is being pumped up by the pump of the washing machine or while taking a bath. In this case, the process returns to the process of step S1 again to prohibit the cleaning operation, and the process of this routine is executed from the beginning. On the other hand, if the determination in step S8 is confirmed, it can be determined that the bathtub 50 is being drained and not being bathed. In this case, the process proceeds to the next step S9, and the operation of the bath circulation pump 52 is started. Then, in the next step S10, the signal of the flow switch 58 is detected.

In the next step S11, it is determined whether or not there is a water flow in the bath circulation circuit 51 based on the signal detected in step S10. When the water level drop time Ts is between the second threshold value B and the third threshold value C, the drainage rate is slower than usual. Therefore, if the washing operation is started with the bathtub water in the bathtub 50, the dirt is not quickly drained and remains in the bathtub 50. The step S10 is a step for determining that there is no bathtub water in the bathtub 50 as a condition for preventing the start of the washing operation as described above.

If it is determined as a result of the determination in step S11 that there is no water flow in the bath circulation circuit 51, it can be determined that there is no bathtub water in the bathtub 50. In this case, information such as the detection result of the water flow is notified by the display on the display unit 72 of the remote controller 71 or the voice from the voice output unit 74, and the process proceeds to the next step S12. In step S12, the operation of the bath circulation pump 52 is stopped, and the process proceeds to the next step S13. In step S13, the automatic cleaning operation is started. Here, specifically, the second cleaning operation of opening the solenoid valve 35 is started while operating the water injection fine bubble generator 55. Further, in this step, the information to start the cleaning operation is notified by the display on the display unit 72 of the remote controller 71 or the voice from the voice output unit 74.

On the other hand, if it is determined in step S11 that there is a water flow in the bath circulation circuit 51, it can be determined that there is bathtub water in the bathtub 50. In this case, information such as the detection result of the water flow is notified by the display on the display unit 72 of the remote controller 71 or the voice from the voice output unit 74, and the process proceeds to the next step S14. In step S14, the operation of the bath circulation pump 52 is stopped. Then, the information that the cleaning operation is not started is notified by the display on the display unit 72 of the remote controller 71 or the voice from the voice output unit 74. When the process of step S14 is performed, the process returns to the process of step S1 again to prohibit the cleaning operation, and the process of this routine is executed from the beginning.

As described above, according to the hot water storage type water heater 100 of the first embodiment, even when the drainage speed of the bathtub 50 is slow, the washing operation is performed when there is no bathtub water in the bathtub 50. As a result, even when the drainage speed of the bathtub 50 is slow, an opportunity for a cleaning operation can be obtained.

By the way, in the hot water storage type water heater 100 of the first embodiment described above, when the water level lowering time Ts is a value between the second threshold value B and the third threshold value C, the cleaning operation is unconditionally prohibited. It may be provided with a configuration for the purpose. As such a configuration, for example, when the determination of step S6 is confirmed in the control routine of FIG. 6, the first mode in which the processing of steps S7 to S14 is performed as usual, and the step S1 unconditionally. The second mode for performing the return process may be configured so that the user can select either mode from the operation unit 73 of the remote controller 71. Thereby, according to the intention of the user, when the drainage speed is slow, it is possible to uniformly prohibit the cleaning operation.

Further, in the hot water storage type water heater 100 of the first embodiment described above, as an automatic cleaning operation, a first cleaning operation using the circulation fine bubble generator 54 or a second cleaning operation using the water injection fine bubble generator 55 is performed. I decided to do it. However, the configuration for performing the automatic cleaning operation is not limited to these, and the automatic cleaning operation may be performed by applying another known configuration for cleaning the pipes or the bathtub.

1 Hot water storage tank unit, 2 Water supply piping, 3 Hot water supply piping, 10 Hot water storage tank, 11 Residual hot water thermista, 21 Heat source pump, 22 User side heat exchanger, 31 1st 3-way valve, 32 2nd 3-way valve, 33 4-way valve, 34 Bath hot water supply piping, 35 electromagnetic valve, 40 tank lower piping, 41 heat pump inlet piping, 42 heat pump outlet piping, 43 1st tank upper piping, 44 2nd tank upper piping, 45 tank return piping, 46 user side heat exchanger primary Side inlet piping, 47 User side heat exchanger primary side outlet piping, 48 Bypass piping, 49 Tank upper return piping, 50 Bathtub, 51 Bath circulation circuit, 52 Bath circulation pump, 53 Bath outlet side thermista, 54 Microbubbles for circulation Generator, 55 Fine bubble generator for water injection, 56 Bath return piping, 57 Bath return piping, 58 Flow switch, 59 Water level sensor, 60 Heat pump unit, 61 Compressor, 62 Boiling heat exchanger, 63 Expansion valve, 64 Air heat exchanger, 65 refrigerant circulation piping, 66 outlet side thermista, 70 control unit, 71 remote control, 72 display unit, 73 operation unit, 74 voice output unit, 100 hot water storage type water heater

Claims (8)

A water level detecting means for detecting the water level in the bathtub,
A circulation circuit for circulating water in the bathtub and
A circulation pump that circulates water in the circulation circuit,
A water flow detecting means for detecting the water flow of the circulation circuit when the circulation pump is driven, and a water flow detecting means.
A cleaning means that performs a cleaning operation that cleans the circulation circuit with air bubbles,
In a hot water supply device including the circulation pump and a control unit for controlling the cleaning means.
The control unit
Based on the water level detected by the water level detecting means, an index value that correlates with the water level decrease time per unit height of the bathtub is calculated.
When the index value is between the first threshold value and the second threshold value in which the water level drop time is larger than the first threshold value and the water level in the bathtub is lower than the determination reference water level, the cleaning operation is performed.
When the index value is between the second threshold value and the third threshold value in which the water level drop time is larger than the second threshold value and the water level in the bathtub is lower than the determination reference water level, the water flow detecting means is used. There line the cleaning operation when the water flow is not detected,
When the index value is a value whose water level drop time is smaller than the first threshold value, the cleaning operation is prohibited.
A water heater characterized by being configured in such a manner. A water level detecting means for detecting the water level in the bathtub,
A circulation circuit for circulating water in the bathtub and
A circulation pump that circulates water in the circulation circuit,
A water flow detecting means for detecting the water flow of the circulation circuit when the circulation pump is driven, and a water flow detecting means.
A cleaning means that performs a cleaning operation that cleans the circulation circuit with air bubbles,
In a hot water supply device including the circulation pump and a control unit for controlling the cleaning means.
The control unit
Based on the water level detected by the water level detecting means, an index value that correlates with the water level decrease time per unit height of the bathtub is calculated.
When the index value is between the first threshold value and the second threshold value in which the water level drop time is larger than the first threshold value and the water level in the bathtub is lower than the determination reference water level, the cleaning operation is performed.
When the index value is between the second threshold value and the third threshold value in which the water level drop time is larger than the second threshold value and the water level in the bathtub is lower than the determination reference water level, the water flow detecting means is used. There line the cleaning operation when the water flow is not detected,
When the index value is a value in which the water level drop time is larger than the third threshold value, the cleaning operation is prohibited.
A water heater characterized by being configured in such a manner. A heating means that heats the water in the hot water storage tank,
A bath hot water supply pipe that connects the upper part of the hot water storage tank and the circulation circuit,
It is equipped with a valve that opens and closes the bath hot water supply pipe.
The cleaning means
The circulation bubble generator installed in the circulation circuit and
It is configured to include a water injection bubble generator installed in the bath hot water supply pipe.
The control unit
When the index value is a value between the first threshold value and the second threshold value and the water level of the bathtub is lower than the determination water level, the circulation pump is driven and the circulation bubble generator is operated.
When the index value is a value in which the water level drop time is larger than the second threshold value and the water flow is not detected by the water flow detecting means, the valve is opened and the water injection bubble generator is operated. The hot water supply device according to claim 1 or 2 , wherein the hot water supply device is characterized by the above. The control unit is configured to prohibit the cleaning operation when the index value is a value between the second threshold value and the third threshold value and the water flow is detected by the water flow detecting means. The hot water supply device according to any one of claims 1 to 3 , wherein the hot water supply device is characterized by the above. The hot water supply device according to any one of claims 1 to 4 , further comprising a setting means for setting the first threshold value or the second threshold value by the user. When the index value is a value between the second threshold value and the third threshold value, the user is further provided with a selection means for selecting a mode for unconditionally prohibiting the cleaning operation. The hot water supply device according to any one of claims 1 to 5. The hot water supply device according to any one of claims 1 to 6 , further comprising a notification means for notifying the detection result of the water flow detecting means. The hot water supply device according to any one of claims 1 to 7 , further comprising a second notifying means for notifying information regarding execution or prohibition of the cleaning operation.

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