Hot water supply system
The water supply device addresses the challenge of detecting water level fluctuations during circulation by using a pressure sensor and control unit to monitor and adjust operations, ensuring accurate detection and energy efficiency.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- MITSUBISHI ELECTRIC CORP
- Filing Date
- 2023-02-22
- Publication Date
- 2026-05-19
AI Technical Summary
Existing water heaters struggle to detect water level fluctuations in a bathtub circulation circuit during operation due to the pressurization effect of the circulation pump, which interferes with pressure sensor readings.
A water supply device with a pressure sensor located in a flow path where no water flows during circulation, coupled with a control unit that monitors pressure sensor values to detect water level fluctuations by comparing them to a baseline, determining water level changes even during circulation, and stopping operations when necessary.
Enables real-time detection of water level changes in a bathtub during circulation, preventing energy loss and improving user convenience by automatically adjusting operations based on water level fluctuations.
Smart Images
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Abstract
Description
Technical Field
[0001] The present disclosure relates to a water supply device.
Background Art
[0002] Conventionally, a water heater has been proposed that detects a water level fluctuation by comparing pressure sensor values that detect the water pressure in a bathtub before and after circulation in a bathtub circulation circuit (see Patent Document 1).
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] However, the water heater proposed in Patent Document 1 detects the water level during circulation stop with a water level detector and determines that a person has taken a bath when there is a water level rise. However, during circulation, the hot water in the bathtub circulation circuit is pressurized by the operation of the circulation pump, so the water level detector cannot obtain a normal pressure sensor value. For this reason, there is a problem that it is impossible to detect in real time the water level fluctuation during circulation when the circulation pump is driven.
[0005] The present disclosure has been made to solve the above-described problems. An object of the present disclosure is to provide a water supply device capable of detecting a water level fluctuation in a bathtub even during circulation of a bathtub circulation circuit.
Means for Solving the Problems
[0006] The water supply device according to the present disclosure includes a bathtub circulation pump that circulates hot water in a bathtub circulation circuit connected to a bathtub, a heat exchanger provided in a flow path from the bathtub circulation pump to the bathtub in the bathtub circulation circuit, and in the bathtub circulation circuit, the heat exchanger from Bathtub To flowThe system includes a pressure sensor connected to a flow path and located in a flow path where no water flows when the bath circulation pump is driven, a control unit that acquires the value of the pressure sensor, and a drainage determination means that determines that the water in the bathtub has been drained when the value of the pressure sensor decreases. The control unit acquires the value of the pressure sensor when the bath circulation pump is driven and monitors the water level fluctuations in the bathtub. When it detects a fluctuation of more than a predetermined value in the value of the pressure sensor, it determines that there has been a water level fluctuation in the bathtub while the bath circulation pump is driven. The control unit then uses the value of the pressure sensor when the bath circulation pump is driven at a predetermined rotation speed and the bath circulation pump The system stores the increase in the pressure sensor value when comparing it to the pressure sensor value when the pump is not running. Using this first pressure sensor value, obtained by adding the increase to the pressure sensor value when the bath circulation pump is not running, the system determines the water level fluctuation in the bathtub when the bath circulation pump is running at a predetermined rotational speed. During the reheating operation, in which the bath circulation pump is driven at a predetermined rotational speed to circulate the water and reheat the water in the bathtub using a heat exchanger, if the pressure sensor value becomes smaller than the first pressure sensor value, the drainage determination means determines that the water has been drained and stops the reheating operation. Furthermore, the hot water supply system relating to this disclosure includes a hot water storage tank, a bath circulation pump that circulates hot water in a bath circulation circuit connected to a bathtub, a heat exchanger installed in the flow path from the bath circulation pump to the bathtub in the bath circulation circuit, and a heat exchanger in the bath circulation circuit from Bathtub To flowThe system includes a pressure sensor connected to a flow path and located in a flow path through which hot water does not flow when the bath circulation pump is driven, and a control unit that acquires the value of the pressure sensor. The control unit acquires the value of the pressure sensor when the bath circulation pump is driven and monitors fluctuations in the water level in the bathtub. When it detects a fluctuation in the pressure sensor value that exceeds a predetermined value, it determines that there has been a water level fluctuation in the bathtub while the bath circulation pump is driven. The control unit stores the increase in the pressure sensor value when the bath circulation pump is driven at a predetermined rotational speed and the pressure sensor value when the bath circulation pump is not driven. Using a first pressure sensor value obtained by adding the increase to the pressure sensor value when the bath circulation pump is not driven, the control unit determines the water level fluctuation in the bathtub when the bath circulation pump is driven at a predetermined rotational speed. During heat recovery operation, in which the bath circulation pump is driven at a predetermined rotational speed to circulate hot water and return the heat of the hot water in the bathtub to the hot water storage tank using a heat exchanger, if the value of the pressure sensor becomes larger than the first pressure sensor value, it determines that a person has entered the bath and stops the heat recovery operation. [Effects of the Invention]
[0007] According to this disclosure, it is possible to provide a hot water supply device that can detect fluctuations in the water level inside the bathtub even while the bath circulation circuit is running. [Brief explanation of the drawing]
[0008] [Figure 1] This is a diagram showing a hot water supply system according to Embodiment 1. [Figure 2] This is a diagram illustrating the flow of hot and cold water when a reheating operation is performed in the storage-type hot water supply system of Embodiment 1. [Figure 3] This is a diagram illustrating the flow of hot water when a bath heat recovery operation is performed in the hot water storage type hot water supply system of Embodiment 1. [Modes for carrying out the invention]
[0009] Embodiments will be described below with reference to the drawings. Common or corresponding elements in each drawing are denoted by the same reference numerals, and their descriptions are simplified or omitted. In the following description, terms such as "water," "hot water," "warm water," and "hot water" generally refer to liquid water, and may include water ranging from cold to boiling. Furthermore, the configurations shown in the embodiments below are examples of the technical ideas related to this disclosure and can be combined with other known technologies, or multiple technical ideas described in this disclosure can be combined. In addition, it is possible to omit or modify parts of the configuration without departing from the gist of this disclosure.
[0010] Embodiment 1. Figure 1 is a diagram showing the configuration of a storage-type hot water heater 35 according to Embodiment 1. The storage-type hot water heater 35 shown in Figure 1 comprises a tank unit 33, an HP unit 7 that utilizes a heat pump cycle, and a remote control 44 for issuing operation commands or changing set values. The HP unit 7 and the tank unit 33 are connected via HP supply piping 14, HP return piping 15, and electrical wiring (not shown). A control unit 36 is built into the tank unit 33. The operation of various valves, pumps, etc., provided in the tank unit 33 and the HP unit 7 is controlled by the control unit 36, which is electrically connected to them. The control unit 36 and the remote control 44 are connected to communicate with each other. The remote control 44 is equipped with a display unit that displays information such as the status of the storage-type hot water heater 35, an operating unit such as switches for the user to operate, a speaker, a microphone, etc. (not shown). The display unit of the remote control 44 corresponds to a notification means. The remote control 44 may also be equipped with a notification means that outputs voice guidance from the speaker.
[0011] The HP unit 7 functions as a heating means for heating the low-temperature water supplied from the hot water storage tank 8 located in the tank unit 33. The HP unit 7 consists of a compressor 1, a water-refrigerant heat exchanger 3, an expansion valve 4, and an air heat exchanger 6, all connected in a ring shape by refrigerant piping 5 to form a heat pump cycle. The water-refrigerant heat exchanger 3 is used for heat exchange between the refrigerant flowing through the refrigerant piping 5 and the low-temperature water supplied from the tank unit 33.
[0012] The tank unit 33 contains the following various parts and piping. The hot water storage tank 8 is for storing hot water. The third water supply pipe 9c is connected to the water inlet 8a located at the bottom of the hot water storage tank 8. Water supplied from a water source such as a water supply is regulated 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. The hot water inlet outlet 8d located at the top of the hot water storage tank 8 is connected to the hot water supply pipe 21 and the hot water delivery pipe 13b, which supply the hot water stored in the hot water storage tank 8 to the outside of the hot water storage type hot water supply device 35. In the hot water storage tank 8, hot water heated by the HP unit 7 flows in from the hot water inlet outlet 8d, and low-temperature water from the third water supply pipe 9c flows in from the water inlet 8a, so that a temperature difference is created between the top and bottom of the tank. Furthermore, multiple hot water temperature sensors 41, 42, and 43 are mounted on the surface of the hot water storage tank 8 at different heights. By detecting the temperature distribution of the hot water in the hot water storage tank 8 using these sensors, the amount of hot water remaining in the tank 8 is determined, and the HP unit 7 controls the start and stop of the hot water heating operation in the tank 8.
[0013] The tank unit 33 contains a heat source pump 12 and a bath heat exchanger 20. The heat source pump 12 is a pump for circulating hot water through various pipes in the tank unit 33, which will be described later, and is installed on the HP supply pipe 14. The bath heat exchanger 20 is a heat exchanger for heating the bath water, which is the water to be heated on the secondary side, using high-temperature hot water supplied from the hot water storage tank 8 or the HP unit 7. In this embodiment, the bath supply pipe 27a and the bath return pipe 28, which circulate the hot water in the bath 30, are used as examples and explained as the configuration of the secondary side of the bath heat exchanger 20. The bath heat exchanger 20 is installed in the middle of the bath supply pipe 27a and the bath return pipe 28. Furthermore, a bath circulation pump 29 for circulating bath water, a bath return temperature sensor 38 for detecting the temperature of bath water coming out of the bath 30, and a bath supply temperature sensor 37 for detecting the temperature of the heat-exchanged water coming out of the bath heat exchanger 20 are installed in the middle of the bath supply pipe 27a and the bath return pipe 28.
[0014] The inlet three-way valve 11a is a flow path switching means having ports a and b through which hot and cold water flows in, and port c through which hot and cold water flows out. The medium-temperature three-way valve 11b is a flow path switching means having ports a and b through which hot and cold water flows in, and port c through which hot and cold water flows out. The four-way valve 18a is a flow path switching means having ports b and c through which hot and cold water flows in, and ports a and d through which hot and cold water flows out, and is configured to allow switching of the flow path between four paths, ab, ac, bd, and cd. The medium-temperature four-way valve 18b is a flow path switching means having port a through which hot and cold water flows in, ports b and c through which hot and cold water flows out, and port d through which hot and cold water flows in or out, and is configured to allow switching of the flow path between four paths, ab, ac, ad, and cd. The tank unit 33 also has a water outlet pipe 10, a hot water introduction pipe 20a, a first bypass pipe 16, a hot water outlet pipe 20b, and a second bypass pipe 17. The water outlet pipe 10 connects the water outlet 8b located at the bottom of the hot water storage tank 8 to port a of the water inlet three-way valve 11a. The HP supply pipe 14 connects port c of the water inlet three-way valve 11a to the inlet side of the HP unit 7. The HP return pipe 15 connects the outlet side of the HP unit 7 to port c of the four-way valve 18a. The lower hot water supply pipe 13a connects port d of the four-way valve 18a to port a of the medium-temperature four-way valve 18b. The hot water supply pipe 13b connects port d of the medium-temperature four-way valve 18b to the hot water inlet outlet 8d at the top of the hot water storage tank 8. The first bypass pipe 16 connects port a of the four-way valve 18a to the hot water inlet 8c located between the center and bottom of the hot water storage tank 8. The first medium-temperature piping 19a connects port b of the medium-temperature four-way valve 18b to the medium-temperature water inlet 8e in the middle of the hot water storage tank 8. The hot water inlet piping 20a connects port c of the medium-temperature four-way valve 18b to the primary side inlet of the bath heat exchanger 20. The hot water outlet piping 20b connects the primary side outlet of the bath heat exchanger 20 to port b of the inlet three-way valve 11a. The second bypass piping 17 branches off from between the heat source pump 12 and the inlet side of the HP unit 7 in the HP supply piping 14 and connects to port b of the four-way valve 18a.
[0015] The inlet three-way valve 11a is used to switch the flow paths of hot and cold water within the tank unit 33 in two flow path configurations: one in which the water outlet pipe 10 and the HP supply pipe 14 are connected, and another in which the hot water outlet pipe 20b and the HP supply pipe 14 are connected. The medium-temperature three-way valve 11b is used to switch the flow paths of hot and cold water within the tank unit 33 in two flow path configurations: one in which the second water supply pipe 9b and the fourth water supply pipe 9d are connected, and another in which the second medium-temperature pipe 19b and the fourth water supply pipe 9d are connected. The four-way valve 18a is used to switch the flow paths of hot and cold water within the tank unit 33 in four flow path configurations: a configuration in which the HP return pipe 15 and the lower hot water supply pipe 13a are connected, a configuration in which the HP return pipe 15 and the first bypass pipe 16 are connected, a configuration in which the first bypass pipe 16 and the second bypass pipe 17 are connected, and a configuration in which the lower hot water supply pipe 13a and the second bypass pipe 17 are connected.
[0016] The circuit includes a three-way inlet valve 11a that directs the hot water from the bottom of the hot water storage tank 8 to the HP supply pipe 14, a heat source pump 12 for circulating the hot water in the pipes, an HP unit 7 for heating, a four-way valve 18a that can direct the hot water from the HP return pipe 15 to the lower hot water supply pipe 13a, and a medium-temperature four-way valve 18b that can direct the hot water from the lower hot water supply pipe 13a to the first medium-temperature pipe 19a. The three-way inlet valve 11a connects port a and port c, the four-way valve 18a connects port c and port d, and the medium-temperature four-way valve 18b connects port a and port d, thereby creating a flow path for the hot water from the bottom of the hot water storage tank 8 to the hot water supply pipe 13b. In addition, an intermediate hot water temperature sensor 42 is installed in the middle of the hot water storage tank 8, and a lower hot water temperature sensor 43 is installed at the bottom of the hot water storage tank 8, allowing the temperature of the hot water in each to be measured.
[0017] Furthermore, the tank unit 33 has a first water supply pipe 9a, a second water supply pipe 9b, a hot water 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 a water supply, and the second water supply pipe 9b and the third water supply pipe 9c are connected to the other end of the first water supply pipe 9a via a pressure reducing valve 31. The fourth water supply pipe 9d branches off from the middle and is connected to the hot water mixing valve 22 and the bath mixing valve 23, respectively. The hot water supply pipe 21 also branches off from the middle and is connected to the hot water mixing valve 22 and the bath mixing valve 23, respectively. In the middle of the second hot water supply pipe 25, a bath solenoid valve 26 for opening and closing the second hot water supply pipe 25 and a bath flow sensor 45 for detecting the flow rate of hot water passing through the second hot water supply pipe 25 are provided.
[0018] The hot water mixing valve 22 and the bath mixing valve 23 adjust 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 and the fourth water supply pipe 9d, thereby generating hot water at the set temperature set by the user with the remote controller 44 and flowing it into the first hot water supply pipe 24 and the second hot water supply pipe 25, respectively. The hot water whose temperature is adjusted by the hot water mixing valve 22 is supplied from the first hot water supply pipe 24 via the hot water faucet 34 to a faucet (not shown) such as a shower or a kitchen faucet used by the user. On the other hand, the hot water adjusted to the set temperature by the bath mixing valve 23 is supplied from the second hot water supply pipe 25 to the bathtub 30 via the bath solenoid valve 26, the bath flow sensor 45, the bath supply pipe 27a, and the bath return pipe 28.
[0019] A pressure sensor pipe 27b branches off from the bath supply pipe 27a. A pressure sensor 39 is installed in this pressure sensor pipe 27b. The control unit 36 acquires the value of the pressure sensor 39 when the bath circulation pump 29 is running and monitors the water level fluctuations in the bathtub 30. When it detects a fluctuation of more than a predetermined value in the value of the pressure sensor 39, it determines that there was a water level fluctuation in the bathtub 30 while the bath circulation pump 29 was running. When hot water is supplied to the bathtub 30, hot water is supplied to the pressure sensor pipe 27b. When the bath circulation pump 29 is driven and the water is circulated within the bath circulation circuit, the pressure sensor pipe 27b does not become a flow path. This reduces the influence of dynamic pressure due to the flow of hot water during circulation, and makes it possible to monitor the water level fluctuations in the bathtub 30 with the pressure sensor 39 even while the bath circulation pump 29 is running and circulation is in progress. In the following description, the value of the pressure sensor 39 may be referred to as the "pressure sensor value". Also, in this disclosure, when a person enters the bathtub 30, it is referred to as "bathing," and when a person leaves the bathtub 30, it is referred to as "exiting the bath." Furthermore, the act of opening the drain plug of the bathtub 30 and draining the water from inside the bathtub 30 is simply called draining.
[0020] The remote control 44 is equipped with an automatic bath operation function. When automatic bath operation is set, the control unit 36 fills the bathtub with water to the temperature and volume set on the remote control 44. After that, the control unit 36 maintains the set temperature and water level by keeping the bathtub water warm and adding more water as needed. When filling the bathtub with water, the control unit 36 operates the bath circulation pump 29 to check for the presence of water in the bathtub 30 when filling with the amount of water set on the remote control 44. At that time, the value of the pressure sensor 39 when the bath circulation pump 29 is driven at a predetermined rotation speed (for example, 6000 rpm) is acquired, and the pressure sensor value when the bath circulation pump 29 is driven at a predetermined rotation speed is compared with the pressure sensor value when the bath circulation pump 29 is not driven, and the increase in the pressure sensor value when the bath circulation pump 29 is driven at a predetermined rotation speed is stored in the control unit 36. This allows the bath function to be performed when the bath circulation pump 29 is driven at a predetermined rotation speed. When the bath circulation pump 29 is not operating The value obtained by adding the increase in the pressure sensor value during pump operation to the pressure sensor value is the third oneIt can be used as a pressure sensor value. By this, the water level fluctuation during the bath circulation is detected, and the bathing and bathing out into the bathtub 30 and the drainage of the bathtub water are detected.
[0021] The detection of bathing and bathing out into the bathtub 30 during the bath circulation is the first when the bath circulation pump 29 is driven at a predetermined rotational speed. one Based on the pressure sensor value, during the bath circulation, the first one When the pressure sensor value increases by a predetermined amount (for example, 0.3 kPa) or more, the control unit 36 determines that a bath is being taken. On the contrary, when the pressure sensor value returns to the first one pressure sensor value during the bath circulation in a state where it has been determined that a bath is being taken, the control unit 36 determines that the bath is over. Thus, the control unit 36 in the present embodiment corresponds to a bath-taking determination means and a bath-ending determination means.
[0022] Also, based on the first one pressure sensor value when the bath circulation pump 29 is driven at a predetermined rotational speed, during the bath circulation, the first one When the pressure sensor value decreases by a predetermined amount (for example, 0.3 kPa) or more, it is determined as drainage. Thus, the control unit 36 in the present embodiment corresponds to a drainage determination means for determining that the hot and cold water in the bathtub 30 has been drained. When it is determined as drainage, there is a possibility that normal circulation cannot be continued due to air biting or the like thereafter. Therefore, the control unit 36 stops the operation of the bath circulation pump 29. Also, when implementing a function of cleaning the inside of the pipe by a bubble injection means (not shown) that generates microbubbles in the bath supply pipe 27a or the bath return pipe 28, there is a possibility that the pressure is erroneously detected by the bubbles in the pipe. Therefore, the control unit 36 prohibits the determination of the water level fluctuation by the pressure sensor 39.
[0023] When obtaining the value of the pressure sensor 39 by driving the bath circulation pump 29 at a predetermined rotational speed, if the control unit 36 determines that an abnormality has occurred when the pressure sensor value deviates from a predetermined normal range, it stops the bath circulation pump 29 and notifies the user of the occurrence of the abnormality with the remote controller 44. Thereby, the user is informed that an abnormality has occurred in the pressure sensor 39.
[0024] Figure 2 is a diagram illustrating the flow of hot water when reheating is performed in the hot water storage type hot water supply system 35 of Embodiment 1. Thick lines in the figure indicate the circuits through which hot water flows, and arrows indicate the flow of hot water. The reheating function, which is a function during bath circulation, is performed by operating the inlet three-way valve 11a and four-way valve 18a and the medium-temperature four-way valve 18b to switch the flow path after the circulation of bath water is started by the operation of the bath circulation pump 29, and then by driving the heat source pump 12. In order to flow the high-temperature water from the top of the hot water storage tank 8 to the bath heat exchanger 20, the c port and d port of the medium-temperature four-way valve 18b are connected, and the high-temperature water taken from the hot water inlet outlet 8d is passed through the hot water supply pipe 13b and the hot water introduction pipe 20a. The water that has released heat in the bath heat exchanger 20 is then returned to the bottom of the hot water storage tank 8 by connecting the b and c ports of the inlet three-way valve 11a and the a and b ports of the four-way valve 18a, passing through the hot water outlet pipe 20b, the HP supply pipe 14, the heat source pump 12, the second bypass pipe 17, and the first bypass pipe 16, and returning the hot water to the hot water storage tank 8 from the hot water inlet 8c. As a result, heat exchange occurs in the bath heat exchanger 20 from the high-temperature water in the hot water storage tank 8 to the low-temperature bath water, and the heated water is returned to the bath 30 to perform reheating.
[0025] During this reheating operation, the water level fluctuations in the bathtub 30 are monitored by checking the value detected by the pressure sensor 39. For example, if the value of the pressure sensor 39 is detected to be lower than the value of the first pressure sensor during the reheating operation, it is possible that the water in the bathtub 30 is being drained, so the reheating is stopped, and the remote control 44 is used to notify that the reheating operation has been stopped. This reduces the loss of energy that would otherwise be used to heat the water that is being drained.
[0026] Figure 3 is a diagram illustrating the flow of hot water when bath heat recovery operation is performed in the hot water storage type hot water supply system 35 of Embodiment 1. Thick lines in the figure indicate the circuits through which hot water flows, and arrows in the figure indicate the flow of hot water.
[0027] The bath heat recovery operation, a function during bath circulation, is performed after the circulation of bath water is started by the operation of the bath circulation pump 29, the inlet three-way valve 11a, the four-way valve 18a, and the medium-temperature four-way valve 18b are operated to switch the flow path, and then the heat source pump 12 is driven. In order to flow the low-temperature water from the bottom of the hot water storage tank 8 to the bath heat exchanger 20, the a-port and c-port of the inlet three-way valve 11a, the b-port and d-port of the four-way valve 18a, and the a-port and c-port of the medium-temperature four-way valve 18b are connected, and the low-temperature water taken from the water outlet 8b is passed through the water outlet piping 10, the HP supply piping 14, the heat source pump 12, the second bypass piping 17, the lower hot water supply piping 13a, and the hot water introduction piping 20a. The bath heat exchanger 20 recovers heat from the hot water, which then passes through the hot water outlet pipe 20b and the medium-temperature water inlet pipe 20c to return it to the middle section of the hot water storage tank 8. The hot water is then returned to the hot water storage tank 8 from the medium-temperature water outlet 8f. This allows the bath heat exchanger 20 to exchange heat from the high-temperature water in the bathtub 30 to the low-temperature water in the hot water storage tank 8, and the bath heat recovery operation is performed by returning the heated hot water to the middle section of the hot water storage tank 8.
[0028] The control unit 36 monitors the water level fluctuations of the bathtub 30 by checking the value detected by the pressure sensor 39 when the bath heat recovery operation is performed. For example, if the control unit 36 detects that the value of the pressure sensor 39 has risen above the value of the first pressure sensor during the bath heat recovery operation, it may be possible that someone has entered the bathtub 30, so it stops the bath heat recovery operation and notifies the user that the bath heat recovery operation has stopped using the remote control 44. This prevents the water level in the bathtub 30 from dropping and further reduces energy loss.
[0029] As described above, the hot water storage type water heater 35 of this embodiment is equipped with a notification means that notifies the user via the remote control 44 when the pressure sensor 39 detects bathing, bathing out, or drainage while the bath circulation pump 29 is running. This improves convenience.
[0030] The control unit 36 stops the bath circulation pump 29 if the value of the pressure sensor 39 drops by a predetermined value or more from the value of the first pressure sensor while the bath circulation pump 29 is running at a predetermined rotational speed.
[0031] The various aspects of this disclosure are summarized below as an appendix.
[0032] (Note 1) A bath circulation pump that circulates the hot water in the bath circulation circuit connected to the bathtub, A pressure sensor is provided in a flow path that communicates with the bath circulation circuit and through which no hot water flows when the bath circulation pump is driven, A control unit that acquires the value of the pressure sensor, Equipped with, The control unit acquires the value of the pressure sensor when the bath circulation pump is running and monitors fluctuations in the water level in the bathtub, and when it detects a fluctuation of a predetermined value or more in the value of the pressure sensor, it determines that there was a fluctuation in the water level in the bathtub while the bath circulation pump was running. (Note 2) The hot water supply device according to Appendix 1, wherein the control unit acquires the value of the pressure sensor when the bath circulation pump is driven at a predetermined rotational speed and determines the water level fluctuation. (Note 3) The hot water supply device according to Appendix 1 or Appendix 2, wherein the control unit determines the water level fluctuation in the bathtub when the bath circulation pump is driven at a predetermined rotational speed using a first pressure sensor value obtained by adding the value of the pressure sensor when the bath circulation pump is not driven to the value of the pressure sensor when the bath circulation pump is driven at a predetermined rotational speed. (Note 4) The hot water supply device according to Appendix 3, further comprising a bathing determination means that determines that a person has entered the bath when the bath circulation pump is driven at a predetermined rotational speed and the value of the pressure sensor becomes larger than the value of the first pressure sensor compared with the first pressure sensor value. (Note 5) The hot water supply device according to Appendix 4, which includes a bath exit determination means that determines that a person has exited the bath when the value of the pressure sensor returns to the value of the first pressure sensor while the bath circulation pump is being driven at a predetermined rotational speed and the bathing determination means is detecting bathing. (Note 6) A heat exchanger provided in the bath circulation circuit, A drainage determination means that determines that the water in the bathtub has been drained based on a decrease in the value of the pressure sensor, Equipped with, The hot water supply device according to any one of the appendices 3 to 5, wherein, during the reheating operation in which the bath circulation pump is driven at a predetermined rotational speed to circulate the hot water and reheat the hot water in the bathtub with the heat exchanger, if the value of the pressure sensor becomes smaller than the value of the first pressure sensor, the drainage determination means determines that drainage has occurred and stops the reheating operation. (Note 7) Hot water storage tank and A heat exchanger provided in the bath circulation circuit, Equipped with, A hot water supply device according to any one of the appendices 3 to 6, wherein, while performing a heat recovery operation in which the bath circulation pump is driven at a predetermined rotational speed to circulate hot water and the heat of the hot water in the bathtub is returned to the hot water storage tank using the heat exchanger, if the value of the pressure sensor becomes larger than the value of the first pressure sensor, it is determined that a person has entered the bath and the heat recovery operation is stopped. (Note 8) A hot water supply system according to any one of the appendices 1 to 7, comprising a notification means for notifying the user when bathing, exiting the bath, or draining water is detected by the pressure sensor while the bath circulation pump is in operation. (Note 9) The hot water supply device according to any one of the appendices 3 to 7, wherein the control unit stops the bath circulation pump if the value of the pressure sensor drops by a predetermined value or more from the value of the first pressure sensor while the bath circulation pump is being driven at a predetermined rotational speed. (Note 10) The hot water supply device according to any one of the appendices 1 to 9, wherein when the bath circulation pump is rotating at a predetermined rotational speed, if the value of the pressure sensor deviates from a predetermined normal range, the control unit determines that an abnormality has occurred, stops the bath circulation pump, and notifies the system of the abnormality using a notification means. (Note 11) The bath circulation circuit is further provided with a bubble injection means for injecting bubbles, The hot water supply device according to any one of the appendices 1 to 10, wherein the control unit does not perform the determination of water level fluctuations by the pressure sensor when bubbles are injected into the hot water by the bubble injection means while the hot water is being circulated in the bath circulation circuit by the bath circulation pump. [Explanation of symbols]
[0033] 1 Compressor, 3 Water refrigerant 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, 8e Medium-temperature water inlet, 8f Medium-temperature water outlet, 9a First water supply piping, 9b Second water supply piping, 9c Third water supply piping, 9d Fourth water supply piping, 10 Water outlet piping, 11a Inlet three-way valve, 11b Medium-temperature three-way valve, 12 Heat source pump, 13a Lower hot water supply piping, 13b Hot water supply piping, 14 HP supply piping, 15 HP return piping, 16 First bypass piping, 17 Second bypass piping, 18a Four-way valve, 18b Medium-temperature four-way valve, 19a 19b First medium-temperature piping, 20 Second medium-temperature piping, 20 Heat exchanger for bath, 20a Hot water inlet piping, 20b Hot water outlet piping, 20c Medium-temperature water inlet piping, 21 Hot water supply piping, 22 Hot water supply mixing valve, 23 Bath mixing valve, 24 First hot water supply piping, 25 Second hot water supply piping, 26 Solenoid valve for bath, 27a Bath supply piping, 27b Pressure sensor piping, 28 Bath return piping, 29 Bath circulation pump, 30 Bathtub, 31 Pressure reducing valve, 33 Tank unit, 34 Hot water tap, 35 Storage-type hot water supply device, 36 Control unit, 37 Bath supply temperature sensor, 38 Bath return temperature sensor, 39 Pressure sensor, 41 Storage temperature sensor, 42 Intermediate storage temperature sensor, 43 Lower hot water storage temperature sensor, 44 Remote control, 45 Bath flow sensor
Claims
1. A bath circulation pump that circulates the hot water in the bath circulation circuit connected to the bathtub, In the bath circulation circuit, a heat exchanger is provided in the flow path from the bath circulation pump to the bathtub, A pressure sensor is provided in the bath circulation circuit, which is in communication with the flow path from the heat exchanger to the bathtub, and in a flow path where hot water does not flow when the bath circulation pump is driven. A control unit that acquires the value of the pressure sensor, A drainage determination means that determines that the water in the bathtub has been drained based on a decrease in the value of the pressure sensor, Equipped with, The control unit acquires the value of the pressure sensor when the bath circulation pump is running and monitors the water level fluctuations in the bathtub. When it detects a fluctuation of more than a predetermined value in the pressure sensor, it determines that there was a water level fluctuation in the bathtub while the bath circulation pump was running. The control unit stores the increase in the pressure sensor value when the bath circulation pump is driven at a predetermined rotational speed compared to the pressure sensor value when the bath circulation pump is not driven, and uses a first pressure sensor value obtained by adding the increase to the pressure sensor value when the bath circulation pump is not driven to determine the water level fluctuation in the bathtub when the bath circulation pump is driven at the predetermined rotational speed. During the reheating operation, in which the bath circulation pump is driven at the predetermined rotational speed to circulate the hot water and reheat the hot water in the bathtub using the heat exchanger, if the value of the pressure sensor becomes smaller than the value of the first pressure sensor, the drainage determination means determines that drainage has occurred and stops the reheating operation. Hot water supply system.
2. The hot water supply device according to claim 1, further comprising a bathing determination means that determines that a person has entered the bath when the bath circulation pump is driven at the predetermined rotational speed and the value of the pressure sensor becomes larger than the value of the first pressure sensor compared with the value of the first pressure sensor.
3. The hot water supply device according to claim 2, further comprising a bath exit determination means that determines that a person has exited the bath when the value of the pressure sensor returns to the first pressure sensor value while the bath circulation pump is being driven at the predetermined rotation speed and the bathing determination means has detected bathing.
4. Hot water storage tank and A bath circulation pump that circulates the hot water in the bath circulation circuit connected to the bathtub, In the bath circulation circuit, a heat exchanger is provided in the flow path from the bath circulation pump to the bathtub, A pressure sensor is provided in the bath circulation circuit, which is in communication with the flow path from the heat exchanger to the bathtub, and in a flow path where hot water does not flow when the bath circulation pump is driven. A control unit that acquires the value of the pressure sensor, Equipped with, The control unit acquires the value of the pressure sensor when the bath circulation pump is running and monitors the water level fluctuations in the bathtub. When it detects a fluctuation of more than a predetermined value in the pressure sensor, it determines that there was a water level fluctuation in the bathtub while the bath circulation pump was running. The control unit stores the increase in the pressure sensor value when the bath circulation pump is driven at a predetermined rotational speed compared to the pressure sensor value when the bath circulation pump is not driven, and uses a first pressure sensor value obtained by adding the increase to the pressure sensor value when the bath circulation pump is not driven to determine the water level fluctuation in the bathtub when the bath circulation pump is driven at the predetermined rotational speed. During the heat recovery operation, in which the bath circulation pump is driven at the predetermined rotational speed to circulate the bathwater and return the heat of the bathwater in the bathtub to the hot water storage tank using the heat exchanger, if the value of the pressure sensor becomes larger than the value of the first pressure sensor, it is determined that a person has entered the bath, and the heat recovery operation is stopped. Hot water supply system.
5. The hot water supply device according to claim 1 or 2, further comprising notification means for notifying the user when bathing, bathing out, or drainage is detected by the pressure sensor while the bath circulation pump is in operation.
6. The hot water supply device according to claim 1, wherein the control unit stops the bath circulation pump when the value of the pressure sensor falls by a predetermined value or more from the value of the first pressure sensor while the bath circulation pump is being driven at the predetermined rotation speed.
7. The hot water supply device according to claim 1 or 2, wherein when the bath circulation pump is rotating at the predetermined rotational speed, if the value of the pressure sensor deviates from a predetermined normal range, the control unit determines that an abnormality has occurred, stops the bath circulation pump, and notifies the system of the abnormality using a notification means.
8. The bath circulation circuit is further provided with a bubble injection means for injecting bubbles, The hot water supply device according to claim 1 or 2, wherein the control unit does not perform the determination of water level fluctuations by the pressure sensor when bubbles are injected into the hot water by the bubble injection means while the hot water is being circulated in the bath circulation circuit by the bath circulation pump.