Bath water heater

Abstract

To provide a bath water heater capable of reducing wasteful power.SOLUTION: In a bath water heater including a burner 2, a bath circuit 25, a circulation pump 27 for circulating hot water of the bath circuit 25, bath water flow detection means 26 for detecting hot water flow of the bath circuit 25, bath temperature detection means 28 for detecting the temperature of the hot water, and a control part 41 to have a first antifreezing operation for draining the hot water to the outside of a machine and a second antifreezing operation for performing antifreezing by circulation by the circulation pump 27, the control part with storage means 42 for storing the existence / nonexistence of water flow stores information of water flow existence when the bath water flow detection means detects the water flow existence, stores information of water flow nonexistence in the storage means when the first antifreezing operation is executed, and executes the second antifreezing operation if information of the storage means 42 is the water flow existence and does not execute it in the case of being the water flow nonexistence when the temperature drops below a risk of freezing.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a water heater for a bath, and more particularly to a water heater with a reheating function. [Background technology]

[0002] Conventionally, this type of device has been equipped with a burner, a bath heat exchanger that exchanges heat using the heat from the burner, a bath circuit that circulates the hot water heated by the bath heat exchanger to the bathtub, and a circulation pump that circulates the hot water in the bath circuit, thereby reheating the hot water in the bathtub and keeping it warm (for example, Patent Document 1).

[0003] Even in warm regions in winter, this type of water heater can suffer damage due to the water in the water supply circuit, hot water supply pipes, and bath pipes freezing. To prevent such accidents, the following measures must be taken depending on the coldness of the outside air. (1) The temperature sensor installed in the equipment automatically activates the internal pipe heater and circulation pump to prevent the pipes from freezing. (2) Leave the hot water tap slightly open to allow water to flow and prevent freezing. (3) Drain the hot water supply pipes and bath pipes inside the machine to prevent freezing. In particular, if severe cold weather such as outside temperatures dropping below -15°C was predicted, it was necessary to drain the water from the cabin (3) and unplug the power cord from the outlet. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 3442280 Summary of the Invention [Problem to be solved by the invention]

[0005] However, if the power plug is forgotten to be unplugged after draining the water, the internal pipe heater and circulation pump (1) will be activated when the temperature drops to freezing, even though there is no water in the pipes, resulting in wasted electricity and a shortened pump lifespan.

[0006] The present invention has been made in view of the above background, and has an object to provide a hot water heater for a bath that can reduce wasted power consumption. [Means for solving the problem]

[0007] The present invention has been made to achieve the above-mentioned object, and in claim 1, there is provided a bath tub heating system comprising a burner, a bath circuit through which hot and cold water in a bathtub flows, a bath heat exchanger that transmits combustion of the burner to the bath circuit, at least one of a circulation pump that circulates the hot and cold water in the bath circuit and a bath piping heater that heats the hot and cold water in the bath circuit, bath water flow detection means that detects the flow of hot and cold water flowing in the bath circuit, bath temperature detection means that detects the temperature of the hot and cold water in the bath circuit, and a control unit that controls the combustion of the burner and the operation of at least one of the circulation pump and the bath piping heater, and further comprising a first anti-freeze operation that drains the hot and cold water in the bath circuit outside the device, and a second anti-freeze operation that circulates the hot and cold water in the bath circuit using the circulation pump and the bath piping heater. and a second anti-freeze operation that prevents freezing by heating the hot water in the bath circuit using at least one of the controllers. The bath water heater is equipped with a memory means for storing the presence or absence of water flow detected by the bath water flow detection means, and the control unit stores information that there is water flow in the memory means when the bath water flow detection means detects the presence of water flow, and stores information that there is no water flow in the memory means when the first anti-freeze operation is performed, and when the temperature detected by the bath temperature detection means falls below a predetermined temperature at which freezing may occur, if the information stored in the memory means indicates that there is water flow, the second anti-freeze operation is performed, and if the information stored in the memory means indicates that there is no water flow, the second anti-freeze operation is not performed.

[0008] Claim 2 is characterized in that the bath water heater is provided with a counter that counts the time since the power supply is turned off, and when the power supply is turned back on, if the power supply is turned off for a predetermined time or more, the control unit stores information that there is no water flow in the memory means, indicating that the first anti-freeze operation has been performed, and when the power supply is turned on again, if the power supply is turned off for a time less than the predetermined time, the control unit does not change the information on the presence or absence of water flow stored in the memory means. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a bath water heater that can reduce wasted power. [Brief explanation of the drawings]

[0010] [Figure 1] Schematic configuration diagram of a first embodiment of the present invention [Figure 2] Block diagram of a first embodiment of the present invention [Figure 3] Flowchart of the first embodiment of the present invention DETAILED DESCRIPTION OF THE INVENTION

[0011] A first embodiment of the present invention will be described with reference to FIGS.

[0012] Reference numeral 1 denotes a main body of a latent heat recovery type hot water heater for a bath, which is equipped with a hot water supply circuit 8, a bath circuit 25, and a hot water filling pipe 15, which will be described later, according to a first embodiment.

[0013] 2 is a vaporizing burner that uses kerosene as fuel to generate an upward flame as a heating means. Reference numeral 2a denotes an aluminum die-cast carburetor that vaporizes fuel, 2b denotes a heater provided in carburetor 2a that heats the fuel to a temperature at which it can be vaporized, 2d denotes a vaporization temperature sensor that serves as a vaporization temperature detection means for detecting the temperature of carburetor 2a, 2f denotes an aluminum die-cast mixing chamber that premixes the vaporized gas vaporized in carburetor 2a with primary air, 2g denotes a combustion section that is provided above mixing chamber 2f on the back side of carburetor 2a and burns the premixed gas premixed in mixing chamber 2f, 2h denotes a nozzle that sprays fuel into carburetor 2a, and 2n denotes an electromagnetic pump that pressurizes fuel from fuel tank 2k to nozzle 2h via fuel supply pipe 2j.

[0014] Reference numeral 3 denotes a hot water tap provided at the end of the hot water supply circuit 8 or at a predetermined location. Reference numeral 4 denotes a combustion fan that blows combustion air, and is connected to the inlet of the vaporizer 2a and the mixing chamber 2f via an air supply path 4a. The combustion air drawn in through the combustion air intake port 4b is supplied to the vaporizer 2a as primary air for premixing, and to the mixing chamber 2f as secondary air to be burned in the combustion section 2g.

[0015] 6 is a heat exchanger located above the burner 2, and this heat exchanger 6 is composed of a fin-tube type primary heat exchanger 6c that recovers sensible heat from the combustion heat of the combustion gas generated by combustion in the combustion section 2g and heats the water flowing through the primary heat receiving pipe 6b, and a secondary heat exchanger 6e that recovers latent heat from the combustion gas after passing through the primary heat exchanger 6c and heats the water flowing through the secondary heat receiving pipe 6d.The primary heat exchanger 6c is located above the combustion section 2g, and the secondary heat exchanger 6e is located above the primary heat exchanger 6c.The combustion gas that passes through the primary heat exchanger 6c and then the secondary heat exchanger 6e is exhausted outside the bath water heater 1 through the exhaust port 6f.

[0016] 6g is a drain receiver that collects drain water generated when water vapor in the combustion gas exchanges heat with water flowing through the secondary heat receiving pipe 6d of the secondary heat exchanger 6e and reaches a temperature below the dew point. The drain receiver 6g is located above the primary heat exchanger 6c and below the secondary heat exchanger 6e. Reference numeral 6h denotes a heat exchange temperature sensor that is installed midway along the primary heat receiving pipe 6b and detects the temperature of the hot water flowing inside the primary heat exchanger 6c.

[0017] Reference numeral 7 denotes a drain pipe that leads the drain water collected in the drain receiver 6g to a neutralizer 7a. The neutralizer 7a is also provided with a drain port 7b for discharging drain water to the outside of the main body when the neutralizer 7a is filled with water.

[0018] Reference numeral 8a denotes a water supply pipe that circulates water supplied from a water supply source to the heat exchanger 6, 8b denotes a hot water supply pipe that circulates hot water heated by the heat exchanger 6 and supplies the hot water to the hot water tap 3, and 8c denotes a water supply bypass pipe that branches off from the water supply pipe 8a, bypasses the heat exchanger 6, and is connected to the hot water supply pipe 8b; the primary heat receiving pipe 6b, the secondary heat receiving pipe 6d, the water supply pipe 8a, the hot water supply pipe 8b, and the water supply bypass pipe 8c form a hot water supply circuit 8 through which water circulates. Also, 8d denotes hot water supply pipe heaters provided at various locations in the hot water supply circuit 8 to prevent freezing.

[0019] Reference numeral 10 denotes a mixing valve provided at the connection between the hot water supply pipe 8b and the water supply bypass pipe 8c, which mixes hot water from the hot water supply pipe 8b with water from the water supply bypass pipe 8c and can vary the mixing ratio; 11 denotes a water supply temperature sensor provided in the water supply pipe 8a as a temperature detection means for detecting the water supply temperature; 12 denotes a water supply flow rate sensor provided in the water supply pipe 8a for detecting the flow rate; 13 denotes a heat exchanger outlet temperature sensor provided in the hot water supply pipe 8b as a temperature detection means for detecting the temperature of the hot water heated in the heat exchanger 6; and 14 denotes a hot water temperature sensor provided in the hot water supply pipe 8b as a temperature detection means for detecting the temperature of the hot water mixed in the mixing valve 10.

[0020] 15 is a hot water filling pipe whose one end is connected downstream of the mixing valve 10 provided on the hot water supply pipe 8b and whose other end is connected to the bath return pipe 34 and bath supply pipe 33 connected to the bathtub 50, 16 is a hot water filling valve which serves as an opening and closing valve that controls the flow of hot water in the hot water filling pipe 15 by opening and closing the valve, 17 is a hot water filling flow rate sensor which detects the flow rate of hot water flowing in the hot water filling pipe 15, and 18 is a hot water filling check valve installed in double to prevent the hot water in the hot water filling pipe 15 from flowing back.

[0021] Reference numeral 25 denotes a bath circuit through which bath water heated by a bath heat exchanger 25a thermally coupled to the heat exchanger 6 flows into the bathtub 50. 26 is a bath water flow detection means that detects the flow of bath water in the piping, 27 is a circulation pump that circulates bath water in the bath circuit 25, 28 is a bath temperature sensor that serves as a bath temperature detection means that detects the temperature of the circulating bath water, and 29 is a water level sensor that serves as a bath water detection means that detects the water level in the bathtub 50. The bath circuit 25 is composed of a bath supply pipe 33 that flows the bath water in the bathtub 50 into the bath heat exchanger 25a, a bath return pipe 34 that flows from the bath heat exchanger 25a to the bathtub 50, a circulation pump 27, a bath temperature sensor 28, a bath water flow switch 26, and a water level sensor 29.

[0022] Reference numeral 40 denotes a remote control that can be configured by operating switches, and is equipped with an operation switch 40a that starts combustion of the burner 2 when the water supply flow sensor 12 detects that hot water has been discharged from the hot water tap 3, thereby performing a heating operation to heat the hot water in the heat exchanger 6; a bath automatic switch 40b that commands automatic bath operation, which fills the bathtub 50 with hot water at the bath set temperature until it reaches the set water level, and if it is determined after filling that the bath temperature has dropped by a specified value from the bath set temperature, performs a heat retention operation to heat the bathwater for a specified heat retention time; a temperature change switch 40c that changes the hot water supply set temperature and bath set temperature; a display 40d that displays the current time and set information; and a speaker 40e that announces the changes by voice.

[0023] The remote control 40 also has a piping drain switch 40f for operating a drain mode that drives the circulation pump 27 for a certain period of time to facilitate drainage of water from the hot water supply circuit 8, hot water filling pipe 15, and bath circuit 25 when draining water to prevent freezing.

[0024] Reference numeral 41 denotes a control unit that is configured with a microcomputer that controls the combustion of the burner 2, the combustion fan 4, and the circulation pump 27.

[0025] The bath water heater 1 can select from the following two operations as a means of preventing freezing when the air temperature drops below the freezing point. The first anti-freeze operation is performed when extreme cold of -15°C or below is expected, in which the user manually drains the hot water in the hot water supply circuit 8 and the bath circuit 25 outside the machine, and the second anti-freeze operation is performed when the weather is normally cold, in which the hot water in the bath circuit 25 is circulated using the circulation pump 27 to prevent freezing.

[0026] The first antifreeze operation will be described in detail below. First, the user turns off the operation switch 40a on the remote control 40, closes the water supply main valve (not shown), opens the hot water tap 3, removes the water supply inlet drain plug 82 and the neutralizer drain plug 83, and then operates the pipe drain switch 40f on the remote control 40 to command the water drain mode. When the pipe drain switch 40f is pressed to instruct the water drain mode, the control unit 41 drives the circulation pump 27 for a certain period of time, which makes it easier for the water in the pipes to drain. After that, the user removes the hot water drain valve 85 and the bath water drain valve 86 to drain the water, and finally unplugs the power plug of the bath water heater 1. Finally, by unplugging the power plug of the bath water heater 1 from the outlet, the second anti-freeze operation described below is not performed.

[0027] In the second anti-freeze operation, when the temperature detected by the water supply temperature sensor 11 drops below a temperature at which freezing is likely to occur (for example, 4°C), the control unit 41 energizes the hot water supply pipe heater 8d provided in the hot water supply circuit 8 to heat the water and prevent freezing, and when the temperature detected by the bath temperature sensor 28 similarly drops below a temperature at which freezing is likely to occur (for example, 4°C), the control unit 41 drives the circulation pump 27 to circulate the water in the bathtub 50 and the bath circuit 25 and prevent freezing.

[0028] Reference numeral 42 denotes a storage means for storing the presence or absence of water flow detected by the bath water flow switch 26 as a bath water flow detection means.

[0029] In the present invention, when the bath water flow detection means, that is, the bath water flow switch 26, detects that there is water flow, the control unit 41 stores information that there is water flow in the memory means 42, and when the first anti-freeze operation is performed (preferably after the circulation pump 27 has been driven for a certain period of time), the control unit 41 stores information that there is no water flow in the memory means 42, and when the temperature detected by the bath temperature sensor 28, that is, that is, the bath temperature detection means, falls below a predetermined temperature (e.g., 4°C) at which there is a risk of freezing, if the information stored in the memory means 42 indicates that there is water flow, the control unit 41 performs the second anti-freeze operation, and if the information stored in the memory means 42 indicates that there is no water flow, the control unit 41 does not perform the second anti-freeze operation.

[0030] The present invention further includes a counter 47 that counts the time since the power supply to the bath water heater 1 has been de-energized, and when the power supply to the bath water heater 1 is re-energized and the de-energized time has elapsed for more than a predetermined time, the control unit 41 determines that the first anti-freeze operation has been performed and stores information that there is no water flow in the memory means 42, and when the power supply to the bath water heater 1 is re-energized and the de-energized time is less than the predetermined time, the information on whether there is water flow or not stored in the memory means 42 is not changed.

[0031] The storage means 42 also includes a bath circuit flag FM and a hot water supply circuit flag KM as storage areas for storing the presence or absence of water flow on the bath circuit 25 side and the hot water supply circuit 8 side, respectively.

[0032] Next, the operation of the first embodiment will be described.

[0033] In step S1, it is determined whether the time since the power supply to the bath water heater 1 was turned off has been longer than a predetermined time (for example, 5 hours), and if the predetermined time has passed, it is determined that the first anti-freeze operation has been performed by the user's water draining operation, and that the hot water in the bath circuit 25, the hot water supply circuit 8, and the hot water filling pipe 15 have been emptied, and in step S2, the bath circuit flag FM and the hot water supply circuit flag KM, which store each state, are both reset and assigned a value of 0, thereby storing a state of no water flow.If the predetermined time has passed, it is determined that the power supply was cut off due to a short-term power outage or maintenance, and the information on whether or not there is water flow stored in the memory means 42 is not changed.

[0034] In step S3, it is checked whether there is a bath request such as pouring hot water into the bathtub 50 or reheating the water based on instructions from the remote control 40, and if there is a bath request, heating operation is started in step S4 and hot water is poured into the bathtub 50 or reheated. Thereafter, the bath circuit flag FM is set to 1 to store the state in which water is flowing (step S5). If there is no bath request, the process proceeds to step S6.

[0035] Next, in step S6, it is confirmed by the water supply flow rate sensor 12 whether or not there is a hot water supply request, and if there is a hot water supply request, in step S7, the heating operation is started to carry out the hot water supply operation. Thereafter, the hot water supply circuit flag KM is set to 1 to store the state in which water is flowing (step S8). If there is no hot water supply request, the process proceeds to step S9.

[0036] Then, it is determined whether the temperature detected by the bath temperature sensor 28, which is the bath temperature detection means, is a predetermined temperature (for example, 4°C) at which there is a risk of freezing (step S9), and when it falls below the predetermined temperature, it is determined whether the bath circuit flag FM is 1, that is, whether there is water flow (step S10), and if there is water flow, the circulation pump 27 is driven in step S11 to prevent freezing. If the temperature is not equal to or lower than the predetermined temperature in step S9, or if the bath circuit flag FM is set to 0 in step S10, the operation of the circulation pump 27 is stopped or kept stopped in step S12.

[0037] Similarly, it is determined whether the temperature detected by the water supply temperature sensor 11, which is the water supply temperature detection means, is a predetermined temperature (for example, 4°C) at which there is a risk of freezing (step S13), and when it falls below the predetermined temperature, it is determined whether the hot water supply circuit flag KM is 1, i.e., whether there is water flow (step S14), and if there is water flow, the hot water supply pipe heater 8d is driven in step S15 to prevent freezing. If the temperature is not equal to or lower than the predetermined temperature in step S13, or if the hot water supply circuit flag KM has a value of 0 in step S14, the driving of the hot water supply pipe heater 8d is stopped or the stopped state is maintained in step S16.

[0038] In step S17, it is determined whether the pipe drain switch 40f has been pressed to indicate the drain mode, and if the drain mode has been indicated, the drain mode is implemented in step S18, and in step S19, since the hot water in the bath circuit 25 and the hot water supply circuit 8 has been emptied, both the bath circuit flag FM and the hot water supply circuit flag KM are reset and assigned a value of 0 to establish a state where there is no water flow. In addition, when the water draining mode is performed in step S18, the user performs a water draining operation such as removing the hot water supply drain valve 85. On the other hand, if the water draining mode is not instructed in step S17, the process proceeds to step S3.

[0039] As a result, even if the user forgets to unplug the power plug from the outlet after draining the water, the memory means 42 stores the fact that there is no water in the piping of the hot water supply circuit 8 and the bath circuit 25, so the operation of the circulation pump 27 and the hot water supply pipe heater 8d can be stopped, reducing the amount of power wasted by operating the hot water supply pipe heater 8d and the circulation pump 27 when there is no water flow in the piping. Furthermore, since unnecessary operation of the circulation pump 27 can be suppressed, the risk of the circulation pump 27 breaking down can be reduced and a shortened lifespan can be suppressed.

[0040] In addition, the second anti-freeze operation can prevent freezing of the bath circuit 25 by replacing the driving of the circulation pump 27 with the heating of a bath piping heater installed around the bath circuit 25, or by driving the circulation pump 27 and heating the bath piping heater simultaneously.

[0041] Although the burner 2 has been described as a vaporization type gasification burner, it may also be a pressure spray type gun burner, and the fuel for the burner 2 may be gas instead of oil.

[0042] It should be noted that the other configurations used in this embodiment are presented as examples and are not intended to limit the scope of the invention, and the invention can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, and are also included in the inventions described in the claims and their equivalents. [Explanation of symbols]

[0043] 1: Bath water heater 2: Burner 6: Heat exchanger 25: Bath circuit 25a: Bath heat exchanger 26: Bath water flow switch (bath water flow detection means) 27: Circulation pump 28: Bath temperature sensor (bath temperature detection means) 41: Control unit 42: Storage means 47: Counter 50: Bathtub

Claims

1. Burner and A bath circuit through which hot and cold water flows in the bathtub, a bath heat exchanger that transfers combustion from the burner to the bath circuit; At least one of a circulation pump that circulates hot and cold water in the bath circuit and a bath piping heater that heats the hot and cold water in the bath circuit; a bath water flow detection means for detecting the flow of hot and cold water flowing through the bath circuit; a bath temperature detection means for detecting the temperature of the hot and cold water in the bath circuit; a control unit that controls the combustion of the burner and the driving of at least one of the circulation pump and the bath piping heater, a first antifreeze operation for draining hot water in the bath circuit to the outside of the machine; a second antifreeze operation for preventing freezing by circulating hot water in the bath circuit using the circulation pump and heating the hot water in the bath circuit using at least one of the bath piping heater; In a bath water heater having a storage means for storing the presence or absence of water flow detected by the bath water flow detection means; The control unit When the bath water flow detection means detects the presence of water flow, the information indicating the presence of water flow is stored in the storage means. When the first antifreeze operation is performed, information indicating no water flow is stored in the storage means; When the temperature detected by the bath temperature detection means falls below a predetermined temperature at which there is a risk of freezing, When the information stored in the storage means indicates that there is a water flow, the second anti-freezing operation is carried out, If the information stored in the storage means indicates that there is no water flow, the second anti-freezing operation is not performed. A bath water heater characterized by the above.

2. A counter is provided to count the time since the power supply of the bath water heater is turned off. The control unit When the power supply is re-energized, if the non-energized time is equal to or longer than a predetermined time, storing information indicating that the first antifreeze operation has been performed in the storage means; When the power supply is re-energized, if the non-energized time is less than the predetermined time, The information on the presence or absence of water flow stored in the storage means is not changed.

2. The bath water heater according to claim 1.

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