JP2016057008A - Water heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water heater capable of determining presence/absence of water in a bathtub with high accuracy, and capable of shortening average time required until the end of hot water filling.SOLUTION: A hot water storage type water heater 35 includes control means (control unit 36) for performing water presence/absence determination operation for determining presence/absence of water in a bathtub 30. The control means, in a first water presence/absence determination operation performed at the beginning of water filling, compares the length of time in which presence of the water flow is continuously detected by water flow detection means 46 for detecting presence/absence of the water flow of a bath circulation circuit with a first reference value A, and compares the length of time in which absence of the water flow is continuously detected by the water flow detection means 46 with a second reference value B. The control means, in a second water presence/absence determination operation performed in the middle or the end of the water filling, compares the length of time in which presence of the water flow is continuously detected by the water flow detection means 46 with a third reference value C, and compares the length of time in which absence of the water flow is continuously detected by the water flow detection means 46 with a fourth reference value D. The third reference value C is a value of a shorter time than the first reference value A, and the fourth reference value D is a value of a longer time than the second reference value B.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a water heater.

  Hot water storage water heaters that store hot water heated by heating means such as heat pumps in hot water storage tanks and use hot water taken out of hot water storage tanks to hot water sources such as bathtubs, showers, kitchens, and faucets in bathrooms are widely used. It has been. In a hot water storage type water heater equipped with a recirculation passage provided with a heat exchanger for exchanging heat between hot water supplied from a hot water storage tank or heating means and bathtub water taken out from the bathtub, When tensioning, hot water is supplied into the bathtub through the recirculation circulation passage.

  In the water heater with a hot water filling function disclosed in Patent Literature 1, when a hot water filling start command is issued, the circulation pump of the recirculation circulation path is driven for 1 minute, and the water flow switch is used to drive the circulation water flow of the recirculation circulation path. It is determined whether it has been detected, and when the water flow switch does not detect the circulating water flow, it is determined that there is no hot water in the bathtub. Furthermore, after injecting a sufficient amount of water into the tub, the circulation pump is driven again to determine whether the water flow switch has detected the circulating water flow in the recirculation circulation passage.When the water flow switch does not detect the circulating water flow, Judge as abnormal.

Japanese Patent Laid-Open No. 11-51463

  When water remains in the recirculation circulation passage, the water flow switch may detect the presence of water flow even though there is no water in the bathtub. Further, when air is mixed in the recirculation circulation passage, that is, when so-called air biting occurs, the water flow switch may detect the absence of water flow even though water is present in the bathtub. In order to prevent misjudgment caused by these events, it is determined that there is water in the bathtub when the water flow switch detects that there is a water flow continuously for a certain time or more, or the water flow switch continues for a certain time or more. When it is detected that there is no water flow, it is necessary to determine that there is no water in the bathtub. However, if it does so, the time required to determine the presence or absence of bath water will become long, and there exists a problem that the required time until the hot water filling end becomes long.

  The present invention has been made in order to solve the above-described problems, and provides a water heater that can accurately determine the presence or absence of water in a bathtub and can shorten the average time required for completion of filling. The purpose is to provide.

  A water heater according to the present invention includes a pump that circulates water in a bath circulation circuit that takes out water from the bathtub and returns it to the bathtub, water flow detection means that detects the presence or absence of water flow in the bath circulation circuit, and the bath circulation circuit. The water filling means to fill the bathtub and the pump, the length of time that the water flow detection means continuously detects the presence of water flow, or the water flow detection means continuously detects the absence of water flow Control means for performing a water presence / absence determination operation for determining the presence / absence of water in the bathtub by comparing the length of time with a reference value, and the control means determines whether or not the first water is present at the start of filling In operation, the length of time that the water flow detection means continuously detects the presence of water flow is compared with the first reference value A, and the length of time that the water flow detection means continuously detects the absence of water flow is the second reference value. Compared to B, second water presence / absence judgment is performed in the middle or the end of the hot water filling In operation, the length of time that the water flow detection means continuously detects the presence of water flow is compared with the third reference value C, and the length of time that the water flow detection means continuously detects the absence of water flow is the fourth reference value. Compared with D, the third reference value C is shorter than the first reference value A, and the fourth reference value D is longer than the second reference value B.

  According to the water heater of the present invention, the presence / absence of water in the bathtub can be determined with high accuracy, and the average time required for completion of filling can be shortened.

It is a block diagram which shows the water heater of Embodiment 1 of this invention. It is a flowchart of the control operation which a control part performs in the filling operation of Embodiment 1 of this invention. It is a flowchart of the control operation which a control part performs in the filling operation of Embodiment 1 of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. In addition, the same code | symbol is attached | subjected to the element which is common in each figure, and the overlapping description is abbreviate | omitted. In this specification, “water” is a concept including water of all temperatures from low-temperature cold water to high-temperature hot water.

Embodiment 1 FIG.
FIG. 1 is a configuration diagram illustrating a water heater according to Embodiment 1 of the present invention. As shown in FIG. 1, a hot water storage type water heater 35 according to Embodiment 1 to which a hot water supply device of the present invention is applied includes a tank unit 33 containing a hot water storage tank 8, an HP unit 7 utilizing a heat pump cycle, and a user. And a remote control device 44 for accepting operations such as changing the operation command and setting value. The HP unit 7 and the tank unit 33 are connected via an HP outgoing pipe 14, an HP return pipe 15, and electrical wiring (not shown). The tank unit 33 includes a control unit 36 (control means). The remote control device 44 has a function as a user interface device. The remote control device 44 is connected to the control unit 36 so as to communicate with each other. Although not shown in the drawings, the remote control device 44 includes a display unit that displays information such as the state of the hot water storage water heater 35, an operation unit such as a switch operated by a user, a speaker, a microphone, and the like. In the first embodiment, the display unit or the speaker of the remote control device 44 corresponds to a notification unit that notifies the user of information. The control unit 36 includes a storage unit including a ROM, a RAM, a nonvolatile memory, and the like, an arithmetic processing device (CPU) that executes arithmetic processing based on a program stored in the storage unit, and external to the arithmetic processing device. And an input / output port for inputting and outputting signals. Actuators and sensors included in the hot water storage type hot water heater 35 are electrically connected to the control unit 36. The control unit 36 controls the operation of the hot water storage type water heater 35 based on detection information of sensors, a signal from the remote control device 44, and the like.

  The HP unit 7 has a function of a heating unit that heats the water guided from the tank unit 33. The HP unit 7 includes a refrigerant circuit in which the compressor 1, the water refrigerant heat exchanger 3, the expansion valve 4, and the air heat exchanger 6 are connected in a ring shape with a refrigerant pipe 5, and operates a heat pump cycle. The water refrigerant heat exchanger 3 heats water by exchanging heat between the high-temperature and high-pressure refrigerant compressed by the compressor 1 and water.

  The tank unit 33 incorporates the following various components and piping. The hot water storage tank 8 stores hot water. A third water supply pipe 9 c is connected to a water inlet 8 a provided at the lower part of the hot water storage tank 8. Water (low temperature water) supplied from a water source such as water supply is adjusted to a predetermined pressure by the pressure reducing valve 31 and then flows into the hot water storage tank 8 through the third water supply pipe 9c. A hot water supply pipe 21 and a hot water supply pipe 13 are connected to a hot water introduction outlet 8 d provided in the upper part of the hot water storage tank 8. The hot water heated by the HP unit 7 passes through the hot water supply pipe 13 and flows into the hot water storage tank 8 from the hot water introduction outlet 8d. Hot water is stored in the hot water storage tank 8 by forming a temperature stratification in which the upper side is hot and the lower side is low. On the surface of the hot water storage tank 8, a plurality of hot water storage temperature sensors 42 and 43 are attached at different height positions. These hot water storage temperature sensors 42 and 43 can detect the temperature distribution of hot water in the hot water storage tank 8. The control unit 36 can grasp the remaining hot water amount and the heat storage amount in the hot water storage tank 8 based on the temperature distribution. In the illustrated configuration, the number of hot water storage temperature sensors is two, but three or more hot water storage temperature sensors may be provided.

  The tank unit 33 includes the water pump 12 and the bath heat exchanger 20. The water pump 12 is provided on the HP outgoing pipe 14. The bath heat exchanger 20 is a heat exchanger that heats the bathtub water, which is the water to be heated on the secondary side, using the heat of hot water supplied from the hot water storage tank 8 or the HP unit 7. In the first embodiment, as the secondary side configuration of the bath heat exchanger 20, a bath piping 27 and a bath return piping 28 that circulate bath water stored in the bath 30 will be described as an example. The bath heat exchanger 20 is connected to the bathtub 30 through a bath piping 27 and a bath return piping 28. A bath circulation circuit is formed by the bath heat exchanger 20, the bath piping 27, and the bath return piping 28. A bath circulation pump 29 that circulates bathtub water in the bath circulation circuit and a bath return temperature sensor 38 that detects the temperature of the bath water discharged from the bathtub 30 are provided in the middle of the bath return pipe 28. In the middle of the bath piping 27, a bath temperature sensor 37 that detects the temperature of the bath water discharged from the bath heat exchanger 20, a water flow detection means 46 that detects the presence or absence of a circulating bath water flow, and a bath A water level sensor 47 for detecting the water level in 30 is installed. Although not shown, the bathtub 30 is provided with a bathtub plug (drain plug) for draining the bathtub water. The water flow detection means 46 can be constituted by a known flow switch, flow sensor or the like. When the output of the water flow detection means 46 is ON, this corresponds to the water flow detection means 46 detecting the presence of a water flow. When the output of the water flow detection means 46 is OFF, this corresponds to the water flow detection means 46 detecting the absence of water flow. The water level sensor 47 corresponds to water level detection means for detecting the water level (water surface height) in the bathtub 30 by detecting the pressure in the forward piping 27.

  The tank unit 33 incorporates the three-way valve 11 and the four-way valve 18. The three-way valve 11 is a flow path switching means having an a port and a b port through which hot water flows and a c port through which hot water flows out. The four-way valve 18 is a flow path switching means having a b port and a c port through which hot water flows, and an a port and a d port through which hot water flows out. The four-way valve 18 is configured to be able to switch the flow path among four paths, that is, ab, ac, bd, and cd. The tank unit 33 further incorporates a water outlet port pipe 10, a first bypass pipe 16, a second bypass pipe 17, a hot water inlet pipe 20a, and a hot water outlet pipe 20b. The water outlet port pipe 10 connects a water outlet 8 b provided at the lower part of the hot water storage tank 8 and the a port of the three-way valve 11. The HP outgoing pipe 14 connects the c port of the three-way valve 11 and the water inlet of the HP unit 7. The HP return pipe 15 connects the water outlet of the HP unit 7 and the c port of the four-way valve 18. The hot water supply pipe 13 connects the d port of the four-way valve 18 and the hot water introduction outlet 8 d above the hot water storage tank 8. The first bypass pipe 16 connects the a port of the four-way valve 18 and the hot water inlet 8 c of the hot water storage tank 8. The hot water inlet 8c is provided at any position between the lower part of the hot water storage tank 8 and the intermediate height position. The hot water introduction pipe 20 a is branched from the middle of the hot water supply pipe 13 and is connected to the primary side inlet of the bath heat exchanger 20. The hot water outlet pipe 20 b connects the primary side outlet of the bath heat exchanger 20 and the b port of the three-way valve 11. The second bypass pipe 17 branches from between the water pump 12 in the HP outgoing pipe 14 and the water inlet of the HP unit 7 and is connected to the b port of the four-way valve 18.

  The tank unit 33 further includes a first water supply pipe 9a, a second water supply pipe 9b, a hot water supply mixing valve 22, a bath mixing valve 23, a first hot water supply pipe 24, and a second hot water supply pipe 25. One end of the first water supply pipe 9a is connected to a water source such as tap water. The other end of the first water supply pipe 9a is connected to the second water supply pipe 9b and the third water supply pipe 9c via the pressure reducing valve 31. A water supply pipe 9 is constituted by the first water supply pipe 9a, the second water supply pipe 9b, and the third water supply pipe 9c. The downstream side of the second water supply pipe 9b is branched into two and connected to the hot water supply mixing valve 22 and the bath mixing valve 23, respectively. The downstream side of the hot water supply pipe 21 is branched into two and connected to a hot water supply mixing valve 22 and a bath mixing valve 23, respectively. The first hot water supply pipe 24 connects the hot water supply mixing valve 22 and the hot water tap 34. The second hot water supply pipe 25 connects the basin mixing valve 23 and the basin circulation circuit (the basin pipe 27). In the middle of the second hot water supply pipe 25, there are provided an electromagnetic valve 26 for opening and closing the second hot water supply pipe 25 and a flow sensor 45 for detecting the flow rate of hot water passing through the second hot water supply pipe 25.

  The mixing valve 22 for hot water supply is set by the user using the remote control device 44 by adjusting the flow rate ratio between the high temperature hot water supplied from the hot water supply pipe 21 and the low temperature water supplied from the second water supply pipe 9b. Hot water having a temperature is generated and flows into the first hot water supply pipe 24. The hot water whose temperature has been adjusted by the hot water supply mixing valve 22 is supplied from the first hot water supply pipe 24 to a faucet (not shown) such as a shower or a currant used by the user.

  The mixing valve 23 for the bath is set by the user using the remote control device 44 by adjusting the flow rate ratio between the hot water supplied from the hot water supply pipe 21 and the low temperature water supplied from the second water supply pipe 9b. Hot water having a temperature is generated and flows into the second hot water supply pipe 25. When filling the bath 30 with hot water, the bath solenoid valve 26 is opened, and the hot water whose temperature is adjusted by the bath mixing valve 23 is the second hot water supply pipe 25, the bath solenoid valve 26, and the bath flow sensor. 45, and further divided into a flow-out piping 27 and a flow-back piping 28, and is supplied into the bathtub 30. The control unit 36 can control the amount of hot water supplied (injected) into the bathtub 30 by controlling the timing for closing the bath solenoid valve 26 based on the detection signal of the bath flow sensor 45.

  The three-way valve 11 can be switched between two flow path forms, a form in which the water outlet pipe 10 and the HP outgoing pipe 14 communicate with each other and a form in which the hot water outlet pipe 20b and the HP outgoing pipe 14 communicate with each other. The four-way valve 18 is configured such that the HP return pipe 15 and the hot water supply pipe 13 communicate with each other, the HP return pipe 15 and the first bypass pipe 16 communicate with each other, and the first bypass pipe 16 and the second bypass pipe 17 communicate with each other. It is possible to switch to four flow path forms, that is, a form in which the hot water supply pipe 13 and the second bypass pipe 17 communicate with each other.

  Next, a heat storage operation performed by the hot water storage type water heater 35 of the first embodiment will be described. In the heat storage operation, the control unit 36 operates the HP unit 7 and the water pump 12. The three-way valve 11 is configured to communicate with the water outlet port pipe 10 and the HP outgoing pipe 14 (ac route). The four-way valve 18 is configured such that the HP return pipe 15 and the hot water supply pipe 13 communicate with each other (cd path). By operating the water pump 12, the water in the lower part of the hot water storage tank 8 passes through the water outlet 8 b, the water outlet port 10, the three-way valve 11, and the HP forward pipe 14, and the water refrigerant heat exchange of the HP unit 7 is performed. Sent to vessel 3. Hot water heated to a high temperature while passing through the water-refrigerant heat exchanger 3 flows into the upper part of the hot water storage tank 8 through the HP return pipe 15, the four-way valve 18, the hot water supply pipe 13, and the hot water introduction outlet 8 d. To do. With such a heat storage operation, hot water is stored in the hot water storage tank 8 from the top to the bottom, so that heat is stored in the hot water storage tank 8.

  Next, the reheating operation performed by the hot water storage type water heater 35 of the first embodiment will be described. The chasing operation is an operation for heating or keeping warm the bathtub water in the bathtub 30. In the chasing operation, the water pump 12 and the bath circulation pump 29 are operated. The three-way valve 11 is configured such that the hot water outlet pipe 20b and the HP outgoing pipe 14 communicate with each other (bc path). The four-way valve 18 is configured to communicate with the first bypass pipe 16 and the second bypass pipe 17 (ab path). By operating the bath circulation pump 29, bath water is drawn from the bath 30 to the bath return pipe 28 and sent to the bath heat exchanger 20. Then, the bath water heated while passing through the bath heat exchanger 20 returns to the bath 30 through the bath piping 27. On the other hand, when the water pump 12 is operated, hot water (high temperature water) led out from the upper part of the hot water storage tank 8 is used as a heat source fluid through the hot water introduction outlet 8d, a part of the hot water supply pipe 13, and the hot water introduction pipe 20a. And is sent to the bath heat exchanger 20. Then, the heat source fluid (medium temperature water) whose temperature has decreased while passing through the bath heat exchanger 20 is the hot water outlet pipe 20b, the three-way valve 11, a part of the HP outgoing pipe 14 (water pump 12), the second bypass pipe. 17, passes through the four-way valve 18, the first bypass pipe 16, and the hot water inlet 8 c and flows into the hot water storage tank 8.

  Next, hot water filling performed by the hot water storage type water heater 35 of the first embodiment will be described. Hot water filling is started when the user operates the remote control device 44. Alternatively, the hot water filling may be automatically started when the time reserved by the remote controller 44 is reached by the user. At the start of hot water filling, the controller 36 supplies hot water having a set amount (for example, 10 L) as priming water from the second hot water supply pipe 25 to the bathtub 30 through the back-up pipe 27 and the back return pipe 28. This priming water is supplied to discharge the air in the bath circulation circuit into the bathtub 30. After supplying the priming water, the controller 36 operates the bath circulation pump 29 and the presence or absence of water in the bathtub 30 by detecting the presence or absence of water by the water flow detection means 46 (first water determination operation (first) Perform water presence / absence judgment operation). In this specification, “there is no water in the bathtub 30” and “there is no water in the bathtub 30” not only means that there is no water in the bathtub 30, but also the water level in the bathtub 30. In addition, it is meant to include the case where the position is lower than the connection position between the bath circulation circuit (the bath piping 27 and the bath return piping 28) and the bathtub 30. Further, “there is water in the bathtub 30” and “there is water in the bathtub 30” means that the water level in the bathtub 30 depends on the bath circulation circuit (the bath piping 27 and the bath return piping 28) and the bath 30. Means higher than the connection position.

  When bath water is contained in the bathtub 30 before the start of hot water filling, in the first water presence / absence determination operation, a circulating water flow of the bathtub water is generated in the bath circulation circuit, and the output of the water flow detecting means 46 is turned on (water flow) Yes). When the controller 36 determines in the first water presence / absence determination operation that there is bathtub water in the bathtub 30, the controller 36 starts a reheating operation and sets the bathtub temperature detected by the bath temperature sensor 38. After the temperature rises, the chasing operation is finished. Then, the control unit 36 completes the hot water filling and notifies the user that the hot water filling has been completed through the display unit or the speaker of the remote control device 44.

  On the other hand, if there is no bathtub water in the bathtub 30 before the start of hot water filling, in the first water presence / absence determining operation, the circulating water flow of the bathtub water is not generated in the bath circulation circuit, and the output of the water flow detecting means 46 is OFF (no water flow). When the control unit 36 determines in the first water presence / absence determination operation that there is no bathtub water in the bathtub 30, the remaining amount obtained by subtracting the amount of priming water from the set amount of hot water set by the user with the remote control device 44. Is supplied (injected) into the bathtub 30. After supplying (injecting) the set amount of hot water into the bathtub 30 as described above, the control unit 36 operates the bath circulation pump 29 again and detects the presence or absence of the water flow with the water flow detection means 46, thereby A water presence / absence determination operation (second water presence / absence determination operation) for determining the presence or absence of water is performed. If the bathtub tap is in a closed state, the hot water injected by the hot water filling operation is accumulated in the bathtub 30. Therefore, in the second water presence / absence determining operation, a circulating water flow of the bathtub water is generated in the bath circulation circuit. The output of the detection means 46 is ON (with water flow). When it is determined in the second water presence / absence determination operation that hot water is accumulated in the bathtub 30, that is, the bathtub water is contained in the bathtub 30, the control unit 36 determines that the hot water filling has been normally completed. Then, the user is notified by the display unit or the speaker of the remote control device 44 that the hot water filling has been normally completed. Furthermore, the control unit 36 stores the bathtub water level detected by the water level sensor 47 as the hot water filling completion water level.

  A cross-sectional area obtained by cutting the internal space of the bathtub 30 along a horizontal plane is hereinafter referred to as a “tub cross-sectional area”. The bathtub cross-sectional area is not necessarily completely constant along the height direction of the bathtub 30, but it is generally constant, so there is no problem even if it is regarded as a constant value. When the hot water is filled, the control unit 36 may calculate and store the bathtub cross-sectional area as follows. The control unit 36 once closes the bathing electromagnetic valve 26 when a certain amount of the set amount of hot water (for example, ½ of the set amount of hot water) is poured into the bath 30, and is detected by the water level sensor 47. The water level is stored as an intermediate water level. Thereafter, the control unit 36 opens the bath solenoid valve 26 to resume the injection of hot water into the bathtub 30 and supplies (injects) the remaining hot water amount of the set hot water amount into the bathtub 30. Thereafter, the control unit 36 performs the second water presence / absence determination operation in the same manner as described above, and when it is determined that the bathtub water is contained in the bathtub 30, it is determined that the hot water filling is normally completed, and the water level is determined. The bathtub water level detected by the sensor 47 is stored as a hot water filling completion water level. The control unit 36 divides the amount of hot water injected into the bathtub 30 from the intermediate water level to the hot water filling completion water level, that is, the hot water amount obtained by subtracting the predetermined amount of hot water from the set hot water amount by the difference between the hot water filling completion water level and the intermediate water level. Thus, the bathtub cross-sectional area can be calculated. The control unit 36 stores the calculated bathtub cross-sectional area.

  When the hot water filling is normally completed, the control unit 36 may control the automatic hot water function as follows. The controller 36 determines whether or not the bathtub water level has decreased by comparing the bathtub water level detected by the water level sensor 47 with the hot water filling completion water level. When it is determined that the bathtub water level has decreased, the control unit 36 multiplies the difference between the hot water filling completion water level and the current bathtub water level detected by the water level sensor 47 by the bathtub cross-sectional area, so that the required hot water supply amount is obtained. Is calculated. The controller 36 can control the automatic hot water function of automatically recovering the lowered bathtub water level to the original hot water filling completion level by injecting the necessary hot water supply amount into the bathtub 30.

  If the user has forgotten to close the bathtub plug before the hot water filling, the hot water injected into the bathtub 30 does not accumulate in the bathtub 30. The circulating water flow of the bathtub water is not generated in the circulation circuit, and the output of the water flow detection means 46 is OFF (no water flow). When it is determined in the second water presence / absence determination operation that the bathtub water is not contained in the bathtub 30, the control unit 36 determines that the bathtub stopper has been removed and stores the water filling completion water level and the bathtub cross-sectional area. Without notifying, the user is notified by the display unit or the speaker of the remote control device 44 that the bathtub stopper has been removed.

  2 and 3 are flowcharts of the control operation executed by the control unit 36 in the hot water filling operation of the hot water storage type water heater 35 of the first embodiment. Hereinafter, based on this flowchart, the hot water filling operation in the first embodiment will be described in more detail. When the user instructs hot water filling with the remote control device 44, or when the hot water filling reservation time comes, the hot water filling is started (step S1 in FIG. 2). When hot water filling is started, the controller 36 supplies 10 L of hot water into the bathtub 30 as the priming water described above in order to discharge the air in the bath circulation circuit to the bathtub 30 (step S2). Thereafter, the control unit 36 turns on the bath circulating pump 29 (operation state) (step S3). The control unit 36 stands by for a certain circulation standby time (for example, 120 seconds) while keeping the bath circulation pump 29 in an operating state (step S4). This circulation waiting time is set to a time during which the bathtub water in the bathtub 30 can be reliably drawn to the water flow detecting means 46 when the bathtub water is contained in the bathtub 30 before the start of hot water filling.

  After the circulation standby time in step S4 has elapsed, the control unit 36 proceeds to step S5. The operations in step S5 and step S6 correspond to the first water presence / absence determination operation performed at the beginning of the hot water filling. In the first water presence / absence determination operation, the control unit 36 first sets the length of time that the water flow detecting means 46 continuously detects the presence of water flow (that is, the length of time that the water flow detecting means 46 is continuously turned on). Compared with the reference value A, the length of time that the water flow detecting means 46 continuously detects no water flow (that is, the length of time that the water flow detecting means 46 is continuously turned off) is compared with the second reference value B. . In this case, the length of time that the water flow detection means 46 continuously detects the presence of water flow and the length of time that the water flow detection means 46 continuously detects the absence of water flow overlap with the circulation waiting time in step S4. The part to do is not included.

  In step S <b> 5, the control unit 36 compares the length of time that the water flow detection unit 46 continuously detects the presence of the water flow with the first reference value A. In the first embodiment, the first reference value A = 60 seconds. If the length of time that the water flow detecting means 46 continuously detects the presence of the water flow in step S5 is less than the first reference value A (60 seconds), the control unit 36 proceeds to step S6. In step S <b> 6, the control unit 36 compares the length of time that the water flow detection unit 46 continuously detects the absence of water flow with the second reference value B. In the first embodiment, the second reference value B = 10 seconds. If the length of time that the water flow detecting means 46 continuously detects no water flow in step S6 is less than the second reference value B (10 seconds), the control unit 36 returns to step S5.

  In this way, the control unit 36 determines that the length of time that the water flow detection means 46 has continuously detected the presence of the water flow reaches the first reference value A (60 seconds) and that the water flow detection means 46 indicates that there is no water flow. The process of step S5 and step S6 is repeated until either of the length of time continuously detected reaches the second reference value B (10 seconds) is established.

  When the length of time that the water flow detecting means 46 continuously detects the presence of the water flow in step S5 is equal to or greater than the first reference value A (60 seconds), the control unit 36 proceeds to step S7, and the bathtub It is determined that there is water in 30. This case corresponds to the case where water already exists in the bathtub 30 before the start of hot water filling. In step S <b> 7, the control unit 36 performs a water-filled hot water operation, which is a hot water-filling operation when water already exists in the bathtub 30 before the start of hot water filling. As the operation of the water-filled hot water filling, the control unit 36 starts the chasing operation, and after the bath temperature detected by the return temperature sensor 38 rises to the set temperature, the chasing operation is finished and the hot water filling is completed. The user is notified of the completion of the hot water filling through the display unit or the speaker of the remote control device 44. The operation of this water-filled hot water filling is omitted in the flowcharts of FIGS.

  On the other hand, if the length of time that the water flow detection means 46 continuously detects no water flow in step S6 is equal to or longer than the second reference value B (10 seconds), the control unit 36 proceeds to step S8. It is determined that there is no water in the bathtub 30. This case corresponds to a case where there is no water in the bathtub 30 before the start of hot water filling. In this case, the control unit 36 performs a waterless hot water filling operation (step S9 and subsequent steps), which is a hot water filling operation when there is no water in the bathtub 30 before the hot water filling starts.

  In general, it is common for the majority of users to drain the old bathtub water in the bathtub 30 before filling the bathtub 30 with water. For this reason, it is normal that there is no water in the bathtub 30 before the start of hot water filling, and in most cases, the operation of waterless hot water filling is performed instead of the operation of water hot water filling. That is, the transition from step S5 to step S7 is a rare case, and in the majority of cases, the transition is from step S6 to step S8. Therefore, when the time until the transition from Step S6 to Step S8 for determining that there is no water in the bathtub 30 becomes longer, the average required time until the end of the hot water is also increased by almost the same amount as the increased time. Become. The longer the second reference value B is, the longer it takes to move from step S6 to step S8. Therefore, in order to shorten the average required time until the hot water filling is completed, it is desirable to set the second reference value B as short as possible. In the first embodiment, by setting the second reference value B to a value shorter than a fourth reference value D described later, the average required time until the filling is completed can be shortened. In the first embodiment, the second reference value B is set to a relatively short time of 10 seconds, so that the average required time until the hot water filling is completed can be further shortened. The second reference value B is desirably set to the minimum necessary time within a range that can reliably prevent malfunction due to noise or the like.

  The longer the first reference value A (60 seconds) is, the longer it takes to move from step S5 to step S7. However, since the transition from step S5 to step S7 is a rare case, even if the time until the transition from step S5 to step S7 for determining that there is water in the bathtub 30 becomes longer, the hot water filling ends. The average travel time to is almost no longer.

  When the total length of the bath circulation circuit exceeds the specified length (for example, the bath piping 27 and the bath return piping 28 are mistakenly installed by the installer with a length exceeding the specified length. In such a case, the circulation standby time in step S4 may be insufficient with respect to the time for drawing the bathtub water in the bathtub 30 to the water flow detecting means 46. Further, when the total length of the bath circulation circuit exceeds the specified length, the remaining water such as priming water remaining in the long bath return pipe 28 flows into the water flow detecting means 46, so that the bathtub Although there is no bathtub water in 30, the water flow detection means 46 may continuously detect the presence of a water flow in step S5. For this reason, when the first reference value A is set to a short time value, there is a possibility of erroneous determination that there is bathtub water in the bathtub 30 even though there is no bathtub water in the bathtub 30. In order to reliably prevent such erroneous determination, it is desirable to set the first reference value A as long as possible. In the first embodiment, the erroneous determination as described above can be reliably prevented by setting the first reference value A to a value longer than the third reference value C described later. In the first embodiment, since the first reference value A is set to a relatively long time of 60 seconds, the erroneous determination as described above can be prevented more reliably. For the reasons described above, even if the first reference value A is a long time value, it is possible to reliably suppress an increase in the average required time until the hot water filling ends.

  Next, the operation of the hot water filling after step S9 will be described. In step S9, the control unit 36 turns off the bath circulation pump 29 (stopped state), and proceeds to step S10. The controller 36 supplies (injects) the remaining amount of hot water obtained by subtracting the amount of priming water from the set amount of hot water into the bathtub 30 in step S10, and proceeds to step S11. After the set amount of hot water is injected into the bathtub 30 in this way, the control unit 36 turns on the bath circulation pump 29 again (operation state) (step S11). The control unit 36 stands by for a certain circulation standby time (for example, 120 seconds) while keeping the bath circulation pump 29 in an operating state (step S12 in FIG. 3). This circulation waiting time is set to a time during which the hot water (tub water) in the bathtub 30 can be reliably drawn to the water flow detection means 46 when the injected hot water is accumulated in the bathtub 30.

  After the circulation standby time in step S12 has elapsed, the control unit 36 proceeds to step S13. The operations of Step S13 and Step S14 correspond to the second water presence / absence determination operation performed at the end of the hot water filling. In the second water presence / absence determination operation, the control unit 36 determines the length of time that the water flow detection means 46 has continuously detected the presence of water flow (that is, the length of time that the water flow detection means 46 has been continuously turned ON) as the third time. Compared with the reference value C, the length of time that the water flow detecting means 46 continuously detects no water flow (that is, the length of time that the water flow detecting means 46 is continuously turned off) is compared with the fourth reference value D. . In this case, the length of time that the water flow detection means 46 continuously detects the presence of water flow and the length of time that the water flow detection means 46 continuously detects the absence of water flow overlap with the circulation standby time in step S12. The part to do is not included.

  In step S <b> 13, the control unit 36 compares the length of time that the water flow detection unit 46 continuously detects the presence of the water flow with the third reference value C. In the first embodiment, the third reference value C = 10 seconds. If the length of time that the water flow detection means 46 continuously detects the presence of the water flow in step S13 is less than the third reference value C (10 seconds), the control unit 36 proceeds to step S14. In step S <b> 14, the control unit 36 compares the length of time that the water flow detection unit 46 continuously detects no water flow with the fourth reference value D. In the first embodiment, the fourth reference value D = 60 seconds. If the length of time that the water flow detection means 46 continuously detects no water flow in step S14 is less than the fourth reference value D (60 seconds), the control unit 36 proceeds to step S15.

  In step S <b> 15, the control unit 36 compares the length of time during which the water flow detection unit 46 continuously detects no water flow with the fifth reference value E. The fifth reference value E is shorter than the fourth reference value D. In the first embodiment, the fifth reference value E = 10 seconds. The operation in step S15 corresponds to an air biting determination operation for determining the presence or absence of air biting. The air biting means a state where air is mixed in the inside of the bath circulation circuit. If the length of time that the water flow detection means 46 continuously detects no water flow in step S15 is less than the fifth reference value E (10 seconds), the control unit 36 returns to step S13. When the length of time that the water flow detecting means 46 continuously detects no water flow in step S15 is equal to or greater than the fifth reference value E (10 seconds), the control unit 36 performs the second water presence / absence determination operation. It is determined that air biting has occurred during execution, the process proceeds to step S18, and the air biting flag is turned on to store the occurrence of air biting during the execution of the second water presence / absence determination operation. Thereafter, the control unit 36 returns from step S18 to step S13.

  In this way, the control unit 36 determines that the length of time that the water flow detection means 46 has continuously detected the presence of the water flow reaches the third reference value C (10 seconds) and that the water flow detection means 46 indicates that there is no water flow. The process of step S13 and step S14 is repeated until either of the length of time continuously detected reaches the fourth reference value D (60 seconds) is satisfied.

  When the length of time that the water flow detecting means 46 continuously detects the presence of the water flow is equal to or greater than the third reference value C (10 seconds) in step S13, the control unit 36 proceeds to step S16, and the bathtub It is determined that there is water in 30. This case corresponds to the case where the hot water injected by hot water is normally accumulated in the bathtub 30. In this case, the control unit 36 stops the bath circulating pump 29 in step S19, and proceeds to step S21.

  In step S21, the control unit 36 determines ON / OFF of the air biting flag. If air biting occurs during the execution of the second water presence / absence determination operation, air may remain in the bath circuit. If air remains in the bath circulation circuit, the water level sensor 47 may not be able to accurately detect the bathtub water level. If the air bit flag is OFF in step S21, air biting has not occurred during the second water presence / absence determination operation, so there is no possibility that air remains in the bath circuit, and the water level The sensor 47 can accurately detect the bathtub water level. In this case, the control part 36 detects the bathtub water level with the water level sensor 47, and memorize | stores the data as a hot water filling completion water level (step S22). On the other hand, if the air bit flag is ON in step S21, there is a possibility that air bite has occurred during the execution of the second water presence / absence determination operation and air remains in the bath circulation circuit. Yes, there is a possibility that the water level sensor 47 cannot accurately detect the bathtub water level. In this case, the control unit 36 does not store the bathtub water level data detected by the water level sensor 47, and does not use the bathtub water level data as the hot water filling completion water level (step S23). In this way, when the length of time that the water flow detecting means 46 continuously detects the absence of water flow records the fifth reference value E or more during the second water presence / absence determination operation, the water level sensor 47 By limiting the use of the detected water level information, it is possible to prevent the detection error of the bathtub water level due to air biting from adversely affecting the control of the automatic hot water function.

  After the operation of step S22 or step S23, the control unit 36 notifies the user that the hot water filling has been normally completed by using the display unit or the speaker of the remote control device 44. Thereafter, when controlling the automatic water filling function, the control unit 36 stores the current hot water filling completion water level (in the case of step S22), based on the current hot water filling completion water level. Control functions. On the other hand, when the hot water filling completion water level is not stored (in the case of step S23), the control unit 36 controls the automatic hot water filling function based on the previous hot water filling completion water level.

  On the other hand, when the length of time that the water flow detecting means 46 continuously detects no water flow in step S14 becomes equal to or longer than the fourth reference value D (60 seconds), the control unit 36 proceeds to step S17. It is determined that there is no water in the bathtub 30. This case corresponds to a case where the bathtub stopper has been removed due to forgetting to close the bathtub stopper, and the hot water injected by the hot water is not normally accumulated in the bathtub 30. In this case, the control unit 36 proceeds to step S20, stops the bath circulation pump 29, and releases the hot water filling. Thereafter, the control unit 36 notifies the user that the bathtub tap has been removed (end of hot water filling) through the display unit or the speaker of the remote control device 44.

  It is a rare case that the bathtub plug is removed when the hot water is filled in the bathtub 30, and in most cases, it is considered that the hot water injected by the hot water is normally accumulated in the bathtub 30. However, even when hot water is accumulated in the bathtub 30, air is mixed into the bath circulation circuit due to some cause such as shaking of the water surface during the circulation operation of the bath circulation circuit in step S12. Biting may occur. In this way, when air biting occurs during the second water presence / absence determination operation, the water flow detection means 46 may continuously detect the absence of water flow. For this reason, there is a case in which the process returns to step S13 through step S14 and step S15 even though hot water is normally accumulated in the bathtub 30. However, the occurrence of such air biting is a rare case.

  From the above, it is a rare case to move from step S14 to step S17, and in the majority of cases, the process moves from step S13 to step S16 without going through steps S14 and S15. Therefore, when the time until the transition from Step S13 to Step S16 for determining that there is water in the bathtub 30 becomes longer, the average required time until the end of the hot water is also increased by almost the same amount as the increased time. Become. The longer the third reference value C is, the longer it takes to move from step S13 to step S16. Therefore, in order to shorten the average required time until the hot water filling is completed, it is desirable to make the third reference value C as short as possible. In the first embodiment, since the third reference value C (10 seconds) is set to a shorter time than the first reference value A (60 seconds), the average required time until the filling is completed can be shortened. Further, in the first embodiment, the third reference value C is set to a relatively short time of 10 seconds, so that the average required time until the filling is completed can be further shortened. The third reference value C is desirably set to the minimum necessary time within a range in which malfunction due to noise or the like can be surely prevented.

  Even when the bathtub plug is removed when the hot water is filled, the total length of the bath circulation circuit exceeds the specified length (for example, the bath pipe 27 and the bath return pipe 28 are installed by the installer. Therefore, the remaining water remaining in the long return pipe 28 flows into the water flow detecting means 46, so that the water flow detecting means 46 is obtained in step S13. May detect the presence of water flow continuously. For this reason, when the third reference value C is set to a short-term value, there is a possibility of erroneous determination that there is bathtub water in the bathtub 30 even though there is no bathtub water in the bathtub 30. However, such a case is a combination of a rare case where the total length of the bath circulation circuit exceeds the specified length and a rare case where the bathtub stopper is removed when filling the bath. This is a rare case. Therefore, even if the third reference value C is set to a short time value, there is a possibility that erroneous determination may occur in such a very rare case, the adverse effect is small, and the above-described advantages are greater. .

  The longer the fourth reference value D (60 seconds) is, the longer it takes to move from step S14 to step S17, and the process moves from step S13 to step S16 via step S14 and step S15. The time until is also longer. However, since the transition from step S14 to step S17 and the transition from step S13 to step S16 via step S14 and step S15 are rare cases, these times become longer. However, the average required time to finish filling is almost not long. That is, even if the fourth reference value D (60 seconds) is a long time value, the average required time hardly increases.

  As described above, when air biting occurs during the second water presence / absence determination operation, the water flow detection means 46 may continuously detect the absence of water flow. Therefore, assuming that the fourth reference value D is a short-term value, when air biting occurs during the execution of the second water presence / absence determination operation, The process proceeds to step S17, where the hot water filling is released and the user may be informed that the bathtub tap has been removed. Such malfunction due to air biting leads to deterioration in usability. In order to reliably prevent such malfunction due to air biting, it is desirable to set the fourth reference value D as long as possible. Further, even when the water flow detection means 46 is in the air-engaged state, by ensuring a sufficient circulation time of the bath circulation pump 29, air is discharged out of the water flow detection means 46, and the air flow detection means 46 is air-engaged. Can be expected to be resolved. Also from this point of view, it is desirable to make the fourth reference value D as long as possible and to ensure a sufficient circulation time of the bath circulation pump 29. In the first embodiment, the fourth reference value D (60 seconds) is set to a value longer than the second reference value B (10 seconds), thereby reliably preventing the malfunction caused by the air biting as described above. it can. In the first embodiment, the fourth reference value D is set to a relatively long time of 60 seconds, so that the erroneous determination as described above can be prevented more reliably. For the reasons described above, even if the fourth reference value D is a long time value, it is possible to reliably suppress an increase in the average required time until the end of the filling.

  Further, in the first embodiment, the fourth reference value D (60 seconds) is set to a value longer than the third reference value C (10 seconds), so that the malfunction caused by the air biting as described above is ensured. Can be prevented.

  It should be noted that when the water flow detection means 46 is in the air-engaged state, not only the air is discharged from the water flow detection means 46 but also a longer time (for example, 120 seconds) for discharging the air out of the circulation circuit. It takes. In the case of air chewing, in order to correctly detect the bathtub water level, it is necessary to stop the water presence / absence determination operation and return to step S12 again. In this Embodiment 1, when air biting generate | occur | produces, it can suppress that hot water filling time becomes long by not returning to step S12 and not memorizing bathtub water level data (step S23).

  As described above, according to the first embodiment, the presence / absence of water in the bathtub 30 can be determined with high accuracy even when the air circulation of the bath circulation circuit occurs, and until the hot water filling ends. The average required time can be shortened. Therefore, convenience for the user can be improved.

  In the description of the flowcharts of FIGS. 2 and 3, the data stored in step S22 is the filling water level data, but the data stored in step S22 is the above-described bathtub cross-sectional area data. Good. In that case, in step S23, the control unit 36 does not store the bath cross-sectional area data, and determines the hot water supply amount of the automatic hot water based on the bath cross-sectional area stored in the previous hot water filling.

  In the first embodiment, the case where the second water presence / absence determination operation is performed at the end of the hot water filling is described as an example. However, in the present invention, in the middle of the hot water filling (for example, when detecting the cross-sectional area of the bathtub). The second water presence / absence determination operation may be performed.

In addition, each of the first reference value A, the second reference value B, the third reference value C, the fourth reference value D, and the fifth reference value E described above is an example, and in a range that satisfies the following expression: It may be changed as appropriate.
First reference value A> Third reference value C
Second reference value B <fourth reference value D
Fourth reference value D> Fifth reference value E
For example, the first reference value A = 75 seconds, the second reference value B = 10 seconds, the third reference value C = 5 seconds, and the fourth reference value D = 30 seconds.

  The first reference value A is preferably 3 times or more of the third reference value C, and more preferably 5 times or more of the third reference value C. Further, the first reference value A is preferably 30 times or less of the third reference value C, and more preferably 20 times or less of the third reference value C. The fourth reference value D is preferably 1.5 times or more of the second reference value B, and more preferably 2 times or more. Further, the fourth reference value D is preferably 10 times or less of the second reference value B, and more preferably 7 times or less. By setting the range as described above, the above-described effects can be achieved more reliably.

DESCRIPTION OF SYMBOLS 1 Compressor, 3 Water refrigerant | coolant heat exchanger, 4 Expansion valve, 5 Refrigerant piping, 6 Air heat exchanger, 7 HP unit, 8 Hot water storage tank, 8a Water inlet, 8b Water outlet, 8c Hot water inlet, 8d Hot water Inlet outlet, 9 water supply pipe, 9a first water supply pipe, 9b second water supply pipe, 9c third water supply pipe, 10 water outlet pipe, 11 three-way valve, 12 water pump, 13 hot water supply pipe, 14 HP outgoing pipe, 15 HP return pipe, 16 first bypass pipe, 17 second bypass pipe, 18 four-way valve, 20 bath heat exchanger, 20a hot water introduction pipe, 20b hot water outlet pipe, 21 hot water supply pipe, 22 hot water mixing valve, 23 Mixing valve, 24 1st hot water supply piping, 25 2nd hot water supply piping, 26 bathing solenoid valve, 27 bathing piping, 28 bathing return piping, 29 bathing circulation pump, 30 bath, 31 pressure reducing valve, 33 Tank unit, 34 Hot water tap, 35 Hot water storage type water heater, 36 Control unit, 37 Bath temperature sensor, 38 Back temperature sensor, 42, 43 Hot water temperature sensor, 44 Remote control device, 45 Flow rate sensor, 46 Water flow detection means 47 Water level sensor

Claims (5)

A pump that circulates water in a bath circulation circuit that takes out the water in the bathtub and returns it to the bathtub;
Water flow detection means for detecting the presence or absence of water flow in the bath circuit,
Filling means for filling the bathtub through the bath circulation circuit;
The pump is operated, and the length of time that the water flow detection means continuously detects the presence of water flow or the length of time that the water flow detection means continuously detects the absence of water flow is compared with a reference value. And a control means for performing a water presence / absence determination operation for determining the presence / absence of water in the bathtub,
With
The control means compares the length of time that the water flow detection means continuously detects the presence of water flow with a first reference value A in the first water presence / absence determination operation performed at the start of the hot water filling, and detects the water flow In the second water presence / absence judgment operation performed in the middle or the end of the hot water filling, the length of time during which the means continuously detects the absence of water flow is compared with the second reference value B. Comparing the length of time detected by the third reference value C, comparing the length of time that the water flow detecting means continuously detects no water flow with the fourth reference value D,
The water heater in which the third reference value C is a value shorter than the first reference value A, and the fourth reference value D is a value longer than the second reference value B.   The water heater according to claim 1, wherein the fourth reference value D is a value longer than the third reference value C. Comprising water level detection means for detecting the water level in the bathtub,
In the second water presence / absence determination operation, the control means has a fifth reference value in which the length of time that the water flow detection means continuously detects no water flow is a value shorter than the fourth reference value D. The water heater according to claim 1 or 2, wherein when E or higher is recorded, use of water level information detected by the water level detection means is restricted.   The hot water supply according to any one of claims 1 to 3, wherein the control means continues the hot water filling when the determination of the presence or absence of water in the bathtub is established in the first water presence / absence determination operation. Machine. Provided with an informing means for informing the user of information;
5. The control device according to claim 1, wherein when the determination of the presence or absence of water in the bathtub is established in the second water presence / absence determination operation, the notification unit notifies the end of the hot water filling. The water heater according to one item.

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