JP7440769B2 - bath water heater - Google Patents

Description

The present invention relates to a bath water supply device.

Japanese Patent No. 3777005 (Patent Document 1) and Japanese Patent No. 3735891 (Patent Document 2) disclose a one-can, two-channel bath water heater. A one-can, two-channel bath water heater is configured so that a heat exchanger for hot water supply and a heat exchanger for reheating are heated by a common burner.

The bath water heater described in Patent Document 1 includes a water level sensor for detecting the water level of hot water in the bathtub (hereinafter also referred to as "bathtub water level"), which is provided in a circulation path for heating hot water in the bathtub. Furthermore, it is equipped with. The water level sensor is constituted by a pressure sensor and detects the bathtub water level based on the bathtub pressure.

Patent No. 3777005 Patent No. 3735891

However, in a one-can, two-channel type bath water heater, hot water stagnant in the circulation circuit is also heated during hot water supply operation in which hot water is supplied with the pump installed on the circulation circuit for reheating stopped. This causes movement in the hot water in the circulation circuit. Due to the movement of the hot water in the circulation circuit, the output of the water level sensor contains many noise components, so there is a problem that the water level in the bathtub cannot be accurately detected while the hot water supply is in standalone operation.

In particular, during intermittent combustion in which the combustion mechanism repeatedly has a combustion period and a non-combustion period in hot water supply operation, the amount of heat generated at the start of the combustion mechanism increases temporarily, so the hot water in the circulation circuit increases. If the temperature of the circulating circuit reaches a temperature close to boiling, there is a problem in that the hot water in the circulation circuit boils and a lot of noise is generated.

This invention was made to solve these problems, and an object of the invention is to provide a bath water heater that can suppress noise components included in the output of a water level sensor. .

According to an aspect of the present invention, a bath water supply device includes a hot water supply heat exchanger, a hot water supply circuit that heats low-temperature water to supply hot water, a reheating heat exchanger, and a circulation pump, a circulation circuit that circulates and heats the hot water; a combustion mechanism that heats the hot water supply heat exchanger and the reheating heat exchanger with a common heat source; and a water level sensor that is connected to the circulation circuit and detects the water pressure of the bathtub water; and a control device that controls each part. The operation modes of the bath water heater include a hot water supply operation, a bath water filling operation using a circulation circuit, and a circulation operation. The control device selectively controls the combustion mechanism between continuous combustion, in which the combustion mechanism continuously burns, and intermittent combustion, in which combustion periods and non-combustion periods of the combustion mechanism are repeatedly provided. In addition, during intermittent combustion during hot water supply operation in which hot water supply operation is performed with hot water filling operation and circulation operation stopped, the control device controls the control device when the temperature of high-temperature water heated by the heat source is lower than a predetermined temperature. The combustion mechanism is controlled in a first pattern in which the amount of heat generated during the combustion period is the first amount of heat. During intermittent combustion during independent hot water supply operation, if the temperature of the high-temperature water heated by the heat source is higher than a predetermined temperature, the control device sets the amount of heat generated during the combustion period to a second amount of heat that is smaller than the first amount of heat. The combustion mechanism is controlled using the second pattern. Then, during intermittent combustion during hot water supply independent operation, the control device detects a change in the bathtub water level based on the detected value of the water level sensor.

According to the present invention, when applying intermittent combustion, if it is determined that the temperature of the high-temperature water heated by the heat source is equal to or higher than a predetermined temperature, the amount of heat generated during the combustion period is set to the second amount of heat, which is smaller than the first amount of heat. Since the combustion mechanism is controlled in a controlled manner, it is possible to prevent the temperature of hot water in the circulation circuit from rising too high. As a result, noise components included in the output of the water level sensor can be suppressed.

1 is a schematic configuration diagram of a bath hot water supply device 10 according to the present embodiment. 2 is a functional block diagram of control device 100 shown in FIG. 1. FIG. It is a figure showing the example of composition of the 1st filter 162a. It is a figure which shows the example of a structure of the 2nd filter 162b. 5 is a flowchart showing a required heat amount setting process executed by the control device 100. FIG. 6 is a diagram showing an example of a control operation and a change over time in the can body temperature Tb when the combustion mechanism 63 is controlled according to the required heat amount setting process shown in FIG. 5. FIG. It is a figure which shows the example of a setting of a combustion period. It is a figure which shows the example of a setting of a combustion period. It is a flow chart for explaining control processing of the bath hot water supply device 10 related to selection of water level data referred to by the bathing/exiting detection unit 164.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, below, the same code|symbol is attached|subjected to the same or equivalent part in a figure, and the description shall not be repeated in principle.

[Bath water heater 10]
FIG. 1 is a schematic configuration diagram of a bath water supply device 10 according to the present embodiment.

Referring to FIG. 1, a bath water heater 10 according to the present embodiment includes a hot water supply circuit 2, a circulation circuit 4, a combustion mechanism 63, and a control device 100 for controlling the bath water heater 10. The bath water heater 10 according to the present embodiment is a one-can, two-channel water heater that heats a hot water supply heat exchanger and a reheating heat exchanger using a common combustion burner.

(Hot water supply circuit 2)
The hot water supply circuit 2 is a circuit for supplying hot water at an appropriate temperature controlled to a hot water supply setting temperature when the hot water supply tap of a shower or the like is opened. The hot water supply circuit 2 includes a primary heat exchanger 61 and a secondary heat exchanger 62 for hot water supply stored in the can body 6, an inlet pipe 21, a can body piping 22, a bypass pipe 23, a hot water outlet pipe 24, It includes a hot water supply pipe 25, a distribution section 32, a flow rate adjustment valve 28, a flow rate sensor 51, and temperature sensors 52, 53, and 54.

The water inlet pipe 21 is connected to a water supply channel such as a waterworks on the upstream side, and is connected to the can body pipe 22 and the bypass pipe 23 via the distribution section 32 on the downstream side. Low temperature water is supplied to the water inlet pipe 21 from a water supply channel. The low-temperature water in the water inlet pipe 21 is distributed to the can body pipe 22 and the bypass pipe 23 via the distribution section 32 .

The distribution unit 32 is configured to be able to adjust the ratio of the flow rate of low-temperature water supplied to the bypass pipe 23 to the flow rate of low-temperature water supplied to the can body pipe 22 (hereinafter also referred to as "distribution ratio k"). . For example, the distribution unit 32 is, for example, a valve, and adjusts the distribution ratio k by controlling the valve opening according to a control command from the control device 100.

Can body piping 22 is connected to secondary heat exchanger 62 . The low-temperature water introduced into the can body piping 22 from the water inlet pipe 21 is first preheated by the secondary heat exchanger 62, and then is mainly heated by passing through the primary heat exchanger 61. High-temperature water heated to a predetermined temperature by the primary heat exchanger 61 and the secondary heat exchanger 62 is discharged from the tap water pipe 24 .

The tapping pipe 24 is connected to the bypass pipe 23 at a confluence point 27 . That is, at the confluence point 27, the high temperature water output from the can body 6 and the low temperature water from the bypass pipe 23 are mixed. Among the low-temperature water from the water inlet pipe 21, the low-temperature water having a flow rate according to the distribution ratio k adjusted by the distribution unit 32 is mixed with high-temperature water at the confluence point 27. In other words, the distribution ratio k (0≦k≦1.0) is the flow rate supplied to the bypass pipe 23 (hereinafter referred to as “bypass flow rate q2'') and is expressed as q2/q1. The distribution ratio k is variably controlled by a set temperature and the like. As a result, hot water at the set temperature is supplied to a predetermined hot water supply location such as the hot water tap 190 or the hot water supply tap of a shower or the like, or the hot water pouring pipe 26 to the bathtub 8. The hot water outlet pipe 24 is provided with a flow rate regulating valve 28 for controlling the hot water supply flow rate.

The temperature sensor 52 is arranged in the can body piping 22 and detects the temperature of low-temperature water (hereinafter also referred to as "inlet water temperature Tw"). The temperature sensor 53 is disposed in a portion of the outlet pipe 24 upstream of the confluence 27 (on the primary heat exchanger 61 side), and detects the temperature of high-temperature water (hereinafter also referred to as "can body temperature Tb"). do. The temperature sensor 54 is disposed in a portion of the hot water tap pipe 24 on the downstream side of the merging point 27, and detects the hot water temperature after mixing the high temperature water and the low temperature water (hereinafter also referred to as the "tapping water temperature Th"). The flow rate sensor 51 is arranged in the can body piping 22 and detects the can body flow rate q1.

(Combustion mechanism 63)
The combustion mechanism 63 has a combustion burner. The combustion burner is configured, for example, by a gun-type burner having an injection nozzle 630 that sprays petroleum (kerosene) as liquid fuel. The combustion mechanism 63 further includes a fuel supply pipe 631, an electromagnetic on-off valve 632, an electromagnetic supply pump 633, a return pipe 634, a flow control valve 635, a blower fan 636, and an ignition transformer 637.

The fuel supply pipe 631 guides liquid fuel (hereinafter also simply referred to as "fuel") from a fuel tank (not shown) to the injection nozzle 630. The electromagnetic on-off valve 632 is disposed in the fuel supply pipe 631 and turns on and off the fuel supply to the fuel supply pipe 631 by opening and closing in response to a control command from the control device 100. The electromagnetic supply pump 633 is disposed in the fuel supply pipe 631 and boosts the pressure of fuel supplied via the electromagnetic on-off valve 632 in an open state in response to a control command from the control device 100. The pressurized fuel is injected from the injection nozzle 630 in the form of mist.

A blower fan 636 supplies combustion air to the combustion burner. The fuel injected from the injection nozzle 630 is mixed with combustion air from the blower fan 636. By being ignited by the ignition transformer 637, the fuel from the injection nozzle 630 is combusted and a flame is generated. Combustion heat generated by the flame from the combustion burner is provided to primary heat exchangers 60, 61 within the can 6. A smoke stack 64 is provided on the downstream side of the can body 6 in the flow direction of the combustion gas for discharging the combustion exhaust gas after heat exchange. The latent heat of the combustion exhaust gas is given to the secondary heat exchanger 62 within the flue gas stack 64 .

The return pipe 634 is configured to return a portion of the liquid fuel supplied by the fuel supply pipe 631 to the fuel supply pipe 631. A flow control valve 635 for controlling the flow rate of return oil is arranged in the return pipe 634. The valve opening degree of the flow rate control valve 635 is adjusted according to a control command from the control device 100. By adjusting the flow rate of the return oil by the flow rate control valve 635, the amount of fuel sprayed from the injection nozzle 630 is controlled. Basically, the amount of combustion by the combustion burner is proportional to the amount of fuel. Therefore, by controlling the opening degree of the flow rate control valve 635, the amount of combustion by the combustion burner can be controlled.

(Circulation circuit 4)
The circulation circuit 4 is a circuit for circulating hot water (hereinafter also referred to as "bathtub water") in the bathtub 8. The circulation circuit 4 includes a primary heat exchanger 60 for reheating, and a circulation pump 34 for circulating bath water within the circulation circuit 4. The circulation circuit 4 can also function as a reheating circulation circuit for reheating the bathtub water until it reaches the bath set temperature by circulation. The primary heat exchanger 60 heats the bathtub water passed through it by the combustion heat of the combustion mechanism 63. Note that the bathtub water may be heated by flowing the bathtub water through a secondary heat exchanger in addition to the primary heat exchanger 60.

A bath return pipe 82 and a bath outgoing pipe 83 are connected to the circulation circuit 4 . The upstream end of the bath return pipe 82 is connected to the suction side of the circulation adapter 81 installed in the bathtub 8 . Further, the downstream end of the bath pipe 83 is connected to the discharge side of the circulation adapter 81 .

When the circulation pump 34 operates, bath water circulates along a path from the suction port of the circulation adapter 81 to the discharge port of the circulation adapter 81 via the bath return piping 82, the primary heat exchanger 60, and the bath outgoing piping 83. do. The reheating function is realized by heating the bathtub water passing through the circulation circuit 4 through the primary heat exchanger 60.

The circulation circuit 4 further includes a water level sensor 55. The water level sensor 55 is configured, for example, by a pressure sensor, and is based on the pressure applied to the piping of the circulation circuit 4 (more specifically, the water pressure in the piping), and determines the water level of the bathtub water in the bathtub 8 (hereinafter referred to as "bathtub water level"). ) is detected. Since the water level sensor 55 is configured to detect minute pressure fluctuations, it has characteristics that make it susceptible to noise. Therefore, filtering processing is required to remove noise from the detected value of the water level sensor 55. The filtering process will be described later.

The bath hot water supply device 10 further includes a hot water pouring pipe 26 that branches off from the hot water tap 24 and fills the bathtub 8 with hot water. The molten metal pouring pipe 26 is branched from the molten metal outlet pipe 24 via a flow rate regulating valve 28 . The molten metal pouring pipe 26 is provided with a molten metal pouring on/off valve 29 . The pouring pipe 26 is connected to the circulation circuit 4 at a junction 26A. By controlling the opening and closing of the hot water pouring on/off valve 29 by the control device 100, formation/blocking of a path for filling hot water from the hot water supply circuit 2 to the bathtub 8 can be controlled.

[Operating mode of bath water heater 10]
The operation modes of the bath water supply device 10 include hot water supply operation, bath water filling operation, and circulation operation. The operation mode further includes a stop mode in which all of the hot water supply operation, bath water filling operation, and circulation operation are stopped.

In the hot water supply operation, low-temperature water supplied to the water inlet pipe 21 is supplied to the secondary heat exchanger 62 and the primary heat exchanger 61 via the can pipe 22. The low temperature water supplied to the secondary heat exchanger 62 is heated by exchanging heat with the latent heat of the combustion exhaust gas, and then is supplied to the primary heat exchanger 61. The heated low-temperature water supplied to the primary heat exchanger 61 becomes high-temperature water by exchanging heat with the combustion heat generated in the combustion mechanism 63. This high-temperature water is supplied to a hot water tap such as the Callan 190 via a hot water outlet pipe 24 and a hot water supply pipe 25.

In the bath water filling operation, the low temperature water supplied to the water inlet pipe 21 is supplied to the secondary heat exchanger 62 and the primary heat exchanger 61 via the can pipe 22. The low temperature water supplied to the secondary heat exchanger 62 is heated by exchanging heat with the latent heat of the combustion exhaust gas, and then is supplied to the primary heat exchanger 61. The heated low-temperature water supplied to the primary heat exchanger 61 becomes high-temperature water by exchanging heat with the combustion heat generated in the combustion mechanism 63. This high-temperature water is supplied to the bathtub 8 through the hot water outlet pipe 24, the hot water pouring pipe 26, the circulation circuit 4, and the outlet of the circulation adapter 81.

In the circulation operation, the circulation pump 34 is operated to circulate bath water through the circulation circuit 4. In the circulation operation, the circulation pump 34 sucks up bathtub water from the suction port of the circulation adapter 81 in the direction of the arrow in the figure. This sucked up bathtub water circulates through a path leading to the discharge port of the circulation adapter 81 via the circulation circuit 4 including the primary heat exchanger 60. Reheating operation is performed by heat-exchanging and heating the bathtub water supplied to the primary heat exchanger 60 using the combustion heat generated in the combustion mechanism 63. Note that the circulation operation can include a bubble generation operation and an air purge operation in addition to the reheating operation. The bubble generation operation is an operation mode in which hot water containing fine bubbles is supplied into the bathtub 8 by using the bubble generation function of the circulation adapter 81. The air purge operation is an operation mode in which air mixed in the circulation circuit 4 is removed by circulating bath water within the circulation circuit 4. In the bubble generation operation and the air purge operation, the combustion mechanism 63 is not combusted, and the circulation pump 34 is operated to circulate bath water in the circulation circuit 4.

[Functions of control device 100]
Next, the functional configuration of the control device 100 will be explained.

The control device 100 controls the operation of the bath hot water supply device 10 in response to user operations and detection values from each sensor. For example, user operations include on/off instructions for hot water supply operation, bath water filling operation, and reheating operation, and settings of hot water supply temperature and bath temperature setting, which are input by operating an operation switch provided on a remote controller (not shown). .

FIG. 2 is a functional block diagram of the control device 100 shown in FIG. 1. The functions of each block in FIG. 2 can be realized by software processing in which the control device 100 executes a program stored in advance. Alternatively, it is also possible to implement part or all of each block by hardware processing using a dedicated electronic circuit. Referring to FIG. 2, control device 100 includes an operation control section 120 and a water level detection section 160.

(Operation control unit 120)
The operation control section 120 includes an operation mode setting section 122, a required heat amount calculation section 124, a combustion control section 126, and a distribution rate control section 128.

The operation mode setting unit 122 manages the start and end (stop) of each operation mode of hot water supply operation, bath water filling operation, and circulation operation. Note that the driving mode setting unit 122 can manage the start and end (stop) of each driving mode so that multiple types of driving modes are controlled in parallel.

For example, when the operation mode setting unit 122 determines that the amount of water flowing from the water supply channel to the bath hot water supply device 10 exceeds the minimum operating flow rate (MOQ) based on the output of the flow rate sensor, the operation mode setting unit 122 starts the hot water supply operation. Further, when the operation mode setting unit 122 determines that the amount of water flowing from the water supply channel to the bath hot water supply device 10 has fallen below the minimum operating flow rate (MOQ), the operation mode setting unit 122 stops the hot water supply operation.

The operation mode setting unit 122 starts the bath water filling operation when an instruction to turn on the bath water filling operation is given by operating an operation switch provided on the remote controller. After starting the bath water filling operation, the operation mode setting unit 122 starts the bath water filling operation when the bath water level reaches a set water level and the bath water temperature detected by a temperature sensor (not shown) reaches the bath set temperature. to stop. Note that the operation mode setting unit 122 calculates the amount of water (volume) poured into the bathtub 8 by integrating the flow rate (metal pouring flow rate) detected by a flow rate sensor (not shown) arranged in the pouring pipe 26. can do.

The operation mode setting unit 122 starts the circulation operation when an instruction to turn on the circulation operation is given by operating the operation switch provided on the remote controller. In addition, the bath water heater 10 may be set to an automatic mode in which the bath water temperature and bath water level are maintained after the bath water filling operation is completed. When the automatic mode is set, if the bathtub water temperature detected by the temperature sensor falls below the reference temperature set corresponding to the bath set temperature (for example, set 2 to 3 degrees Celsius lower than the bath set temperature), the operation will start. The mode setting unit 122 starts reheating operation. Furthermore, when the bathtub water level detected by the water level sensor 55 falls below the set water level, the operation mode setting unit 122 starts a supplementary hot water operation in which hot water is additionally poured from the bath water supply device 10 into the bathtub 8.

Note that, if the operation mode setting unit 122 determines to start the circulation operation or the bath water filling operation during execution of the hot water supply operation, the operation mode setting unit 122 executes the circulation operation or the bath water filling operation simultaneously with the hot water supply operation. In this specification, in the hot water supply operation, a case where neither the circulation operation nor the bath water filling operation is performed is referred to as a "hot water supply independent operation."

Although not shown, the operation mode setting unit 122 controls the circulation pump 34, the flow rate adjustment valve 28, the hot water pouring on/off valve 29, etc. according to the start/stop of various operation modes.

The required heat amount calculation unit 124 calculates the amount of heat required for the bath water heater 10 per unit time based on the controlled operation mode, target temperature Tr* (set temperature), inlet water temperature Tw, can body flow rate q1, distribution ratio k, etc. Calculate the required amount of generated heat Qrq, which is the amount of heat. As an example, a method for calculating the required amount of generated heat Qrq when controlled to at least one of hot water supply operation and bath water filling operation will be described.

For the bath hot water supply device 10, the amount of heat for raising the inlet water temperature Tw to the target temperature Tr* is generated for the flow rate of water supplied from the water inlet pipe 21 (hereinafter also referred to as "total flow rate qt"). This is required. Therefore, the required amount of generated heat Qrq when controlled to at least one of the hot water supply operation and the bath water filling operation can be calculated according to the following equation (1).

Qrq=qt・(Tr*−Tw)…(1)
Note that, in reality, it is necessary to consider the ratio (thermal efficiency) of the amount of heat used to raise the temperature in the primary heat exchangers 60, 61 and the secondary heat exchanger 62 out of the amount of heat generated by the combustion mechanism 63. In the following, in order to simplify the explanation, it is assumed that the thermal efficiency is 1.0. Further, in bath water heaters, the required amount of heat to be generated is generally calculated in units of "number". The number = 1 corresponds to the amount of heat required to raise the water temperature by 25° C. under a flow rate of qt = 1 (L/min).

The total flow rate qt is calculated from the distribution ratio k and the can body flow rate q1. Therefore, the required heat amount calculation unit 124 calculates the inlet water temperature Tw from the temperature sensor 52, the target temperature Tr*, The required amount of generated heat Qrq is calculated based on the can body flow rate q1 from the flow rate sensor 51 and the distribution rate k set by the distribution rate control unit 128. Note that the total flow rate qt may be obtained by providing a flow rate sensor on the water inlet pipe 21.

The combustion control unit 126 sets the operating state of the combustion mechanism 63 to continuous combustion in which the combustion period of the combustion mechanism 63 is provided continuously, and combustion period and non-combustion period of the combustion mechanism 63 are repeated, based on the required amount of generated heat Qrq. Set to either one of the intermittent combustion and intermittent combustion provided. The combustion control unit 126 then generates a control command to the combustion mechanism 63 according to the set operating state.

The combustion control unit 126 controls the operating state of the combustion mechanism 63 when the required amount of generated heat Qrq is less than the amount of heat that can be continuously and stably generated by the combustion mechanism 63 (hereinafter also referred to as "minimum amount of generated heat Q1"). Set to "intermittent combustion". Here, the minimum amount of heat generated Q1 corresponds to the amount of heat generated when the amount of combustion sprayed from the injection nozzle 630 is set to a lower limit value that can ensure a stable combustion state, and is predetermined as the capacity of the combustion mechanism 63. ing.

When the operating state of the combustion mechanism 63 is set to continuous combustion, the combustion control unit 126 causes the combustion mechanism 63 to continuously burn so that the amount of heat according to the required amount of generated heat Qrq calculated by the required amount of heat calculation unit 124 is generated. .

When the operating state of the combustion mechanism 63 is set to intermittent combustion, the combustion control unit 126 controls the combustion mechanism 63 so that combustion in the combustion mechanism 63 is performed intermittently. That is, the combustion burner of the combustion mechanism 63 is extinguished and reignited so that combustion periods and non-combustion periods are repeatedly provided. When the hot water supply operation is controlled to be independent and the operating state of the combustion mechanism 63 is set to intermittent combustion, the combustion control unit 126 controls whether the combustion mechanism The amount of heat generated required for 63 is set. In the present embodiment, as an example, the combustion control unit 126 sets the amount of heat generated that is required of the combustion mechanism 63 during the combustion period according to the can body temperature Tb.

The distribution rate control unit 128 controls the target temperature Tr*, the inlet water temperature Tw from the temperature sensor 52, and the can body from the temperature sensor 53 when being controlled to at least one of the hot water supply operation and the bath water filling operation. Based on the temperature Tb and the hot water outlet temperature Th from the temperature sensor 54, a control command to the distribution unit 32 for controlling the hot water outlet temperature Th to the target temperature Tr* is generated.

Specifically, the following equation (2) holds true between the can body flow rate q1, the bypass flow rate q2, the inlet water temperature Tw, the can body temperature Tb, and the outlet hot water temperature Th. Therefore, the distribution rate control unit 128 can control the distribution rate k(q2/q1) according to the following formula (3) obtained by transforming formula (2) and substituting Th=Tr*. can.

q2・(Th-Tw)=q1・(Tb-Th)...(2)
k=q2/q1=(Tb-Tr*)/(Tr*-Tw)...(3)
(Water level detection unit 160)
The water level detection unit 160 detects changes in the bathtub water level based on the detected value of the water level sensor 55. Since the water level sensor 55 is constituted by a pressure sensor, it can detect even the movement of hot water in the bath return pipe 82, and has a characteristic that it is susceptible to noise. Therefore, the water level detection unit 160 removes high frequency noise components from the detection value of the water level sensor 55. The water level detection unit 160 further detects whether a person enters or leaves the bathtub 8 based on the detected change in the bathtub water level. Specifically, the water level detection section 160 includes a database 161, a noise removal section 162, and a bathing/exiting detection section 164.

The noise removal section 162 includes a first filter 162a and a second filter 162b. Both the first filter 162a and the second filter 162b are noise filters for removing high frequency noise components from the detected value of the water level sensor 55. As described later, the first filter 162a and the second filter 162b differ from each other in noise removal performance and real-time performance. Specifically, the second filter 162b has higher noise removal performance than the first filter 162a. On the other hand, since the second filter 162b uses more data for filter processing than the first filter 162a, it has a property of low real-time performance.

The first filter 162a performs filter processing on the noise superimposed on the detection value of the water level sensor 55, and outputs the water level data from which the noise has been removed to the database. FIG. 3 is a diagram showing an example of the configuration of the first filter 162a.

As shown in FIG. 3, for example, a moving average filter can be used as the first filter 162a. The moving average filter is configured to calculate a simple moving average value z[n] of N sampling points x[n] to x[n−(N−1)] in the detected value of the water level sensor 55.

The second filter 162b performs filter processing on the noise superimposed on the detection value of the water level sensor 55, and outputs water level data from which noise components have been removed to the database. As the second filter 162b, a low-pass filter having a characteristic of attenuating middle and high frequency components without attenuating low frequency components can be applied to overcome the drawbacks of the moving average filter described above. However, although the second filter 162b has higher noise removal performance than the first filter 162a, it has a property that real-time performance is low because the amount of data used for calculation processing is large.

FIG. 4 is a diagram showing a configuration example of the second filter 162b. As shown in FIG. 4, for example, a double moving average filter can be used as the second filter 162b. The double moving average filter calculates a simple moving average value y[n] of M simple moving average values z[n] to z[n-(M-1)] calculated by M moving average filters. is configured to calculate. That is, the double moving average filter is a simple moving average applied twice.

Returning to FIG. 2, the bath entry/exit detection unit 164 detects whether a person enters or leaves the bathtub 8 using the water level data generated by the noise removal unit 162. Specifically, the bathing/leaving detection unit 164 detects bathing/leaving by selectively using either the water level data generated by the first filter 162a or the water level data generated by the second filter 162b. .

In the one-can, two-channel type bath water heater 10, when the water in the hot water supply circuit 2 is heated, the hot water that remains in the circulation circuit 4 (hereinafter also referred to as "stagnant water") is also heated, Movement occurs in the hot water in the return pipe 82. Therefore, in the one-can, two-channel type bath water heater 10, even when the circulation pump 34 is stopped, during the hot water supply operation alone, the hot water supply operation, the bath water filling operation, and the circulation operation are all stopped during the stop mode. In comparison, a lot of noise is added to the output value of the water level sensor 55.

Therefore, the bathing/exiting detection unit 164 selectively selects one of the water level data generated by the first filter 162a and the water level data generated by the second filter 162b, depending on the operating status of the bath water heater 10. use Thereby, the bathing/exiting detection unit 164 can use water level data processed by a filter according to the noise generation situation. A specific selection method will be described later.

[Control method when setting to intermittent combustion during hot water supply standalone operation]
When intermittent combustion is set, the combustion control unit 126 sets the amount of heat generated by the combustion mechanism 63 during the combustion period according to the temperature of the high-temperature water heated by the combustion mechanism 63.

When set to intermittent combustion, the combustion burner is repeatedly ignited and extinguished. When the combustion burner is ignited, a large amount of heat is temporarily generated. Therefore, even during hot water supply operation alone (while the circulation pump 34 is stopped), if the temperature of the hot water in the circulation circuit 4 heated by the primary heat exchanger 60 reaches a temperature close to boiling, the temporary Due to the large amount of heat generated, the hot water in the circulation circuit 4 boils, and the output of the water level sensor 55 contains many noise components. Below, a method for suppressing noise that occurs when intermittent combustion is set during hot water supply independent operation will be explained.

FIG. 5 is a flowchart showing the required heat amount setting process executed by the control device 100. The required heat amount setting process shown in FIG. 5 is repeatedly executed at predetermined intervals, for example, when the intermittent combustion mode is controlled.

In S10, the control device 100 determines whether the can body temperature Tb is lower than a predetermined reference temperature T1.

When the control device 100 determines that the can body temperature Tb is less than the reference temperature T1 (YES in S10), the control device 100 determines to control the bath hot water supply device 10 in the first pattern (S12), and performs the required heat amount setting process. end. The first pattern is a control pattern in which the amount of heat A is required to generate from the combustion mechanism 63 during the combustion period.

When the control device 100 determines that the can body temperature Tb is not less than the reference temperature T1 (NO in S10), that is, when it determines that the can body temperature Tb is equal to or higher than the reference temperature T1, the control device 100 causes the bath water heater 10 to It is decided to perform control using two patterns (S14), and the required heat amount setting process is ended. The second pattern is a control mode in which the amount of heat generated by the combustion mechanism 63 during the combustion period is set to the amount of heat B, which is smaller than the amount of heat A.

In this embodiment, the temperature of the high-temperature water warmed by the combustion mechanism 63 is the can body temperature Tb, which is the temperature of the hot water discharged from the primary heat exchanger 61. The reference temperature T1 is lower than the can body temperature Tb (hereinafter also referred to as "threshold temperature Ts") when the temperature of the accumulated water in the primary heat exchanger 60 is close to the boiling point, and for example, in the second pattern. Even if the combustion mechanism 63 is controlled, the can body temperature Tb does not exceed the threshold temperature Ts for a predetermined period. The reference temperature T1 is set, for example, by conducting an experiment after determining the amount of heat A and the amount of heat B.

The amount of heat A and the amount of heat B are greater than or equal to the minimum amount of heat generated Q1. The amount of heat A and the amount of heat B may be varied depending on the target temperature Tr*, or may be fixed values regardless of the target temperature Tr*. Note that by setting the amount of heat A and the amount of heat B to fixed values regardless of the target temperature Tr*, the burden on setting the reference temperature T1, the amount of heat A, and the amount of heat B can be reduced.

Note that the temperature of the high-temperature water warmed by the combustion mechanism 63 may be determined by the temperature itself of the water remaining in the primary heat exchanger 60, a parameter that affects the temperature change of the water remaining in the primary heat exchanger 60, or the temperature of the water remaining in the primary heat exchanger 60, or This is a parameter that changes depending on the temperature change of the water retained in the exchanger 60. That is, the control pattern may be switched depending on other temperatures instead of the can body temperature Tb. For example, if a temperature sensor is placed near the primary heat exchanger 60, the control pattern may be switched depending on the temperature detected by the temperature sensor. In addition, if a boiling prevention thermistor is arranged on a part (bend) of the output side of the primary heat exchanger 60 or the primary heat exchanger 61, the control pattern is switched depending on the temperature detected by the boiling prevention thermistor. It's okay.

FIG. 6 is a diagram showing an example of a control operation and a change over time in the can body temperature Tb when the combustion mechanism 63 is controlled according to the required heat amount setting process shown in FIG. In the operation example shown in FIG. 6, it is assumed that the independent hot water supply operation with intermittent combustion is started at time t1. Further, in the operation example of FIG. 6, it is assumed that the combustion period and the non-combustion period are the same in the first pattern and the second pattern.

At the start of hot water supply, the can body temperature Tb is low, so the bath water heater 10 is controlled in the first pattern. That is, the combustion mechanism 63 is controlled so that the amount of heat A is generated during the combustion period Ton. When the combustion burner is ignited according to the required amount of heat to be generated, the can body temperature Tb increases. Then, when the non-combustion period Toff starts and the combustion burner is extinguished, the can body temperature Tb decreases. Thereafter, when the combustion period Ton is started again, the combustion burner is ignited according to the required amount of generated heat, and the can body temperature Tb starts to rise again. In the example shown in FIG. 6, since the temperature change in the can body temperature Tb is larger in the combustion period Ton than in the non-combustion period Toff, the can body temperature Tb gradually increases.

When the can body temperature Tb reaches the reference temperature T1 at time t2, the control device 100 switches the control pattern to the second pattern. That is, the required amount of generated heat during the combustion period Ton is set to the amount of heat B, which is smaller than the amount of heat A.

When controlled in the second pattern, the amount of heat generated by ignition of the combustion burner during the combustion period Ton is lower than when controlled in the first pattern, so that the temperature rise during the combustion period Ton is suppressed. As a result, it is possible to suppress the can body temperature Tb from reaching the threshold temperature Ts, and it is possible to suppress noise generated in the water level sensor 55 when intermittent combustion is set during hot water supply independent operation.

In addition, as a method of suppressing the can body temperature Tb from reaching the threshold temperature Ts, there is a method of constantly lowering the amount of heat generated by the combustion mechanism 63 during the combustion period. However, if the required amount of heat to be generated is lowered, the rise in temperature will be delayed, which will worsen the hot water output characteristics. Therefore, in this embodiment, the required amount of generated heat is set high until the can body temperature Tb reaches the reference temperature T1, and the required amount of generated heat is lowered after the can body temperature Tb reaches the reference temperature T1. , can provide good hot water supply characteristics. Thereby, it is possible to both suppress the increase in the can body temperature Tb and maintain the hot water tapping characteristics.

[Distribution rate control during intermittent combustion]
As described above, the distribution rate control unit 128 can control the distribution rate k (q2/q1) according to the above equation (3). The incoming water temperature Tw is the temperature of low-temperature water supplied from the waterworks, and has a small fluctuation range. On the other hand, as shown in FIG. 6, the can body temperature Tb increases from the start of hot water supply. Therefore, the distribution ratio k changes mainly under the influence of the can body temperature Tb.

As shown in FIG. 6, between the first pattern and the second pattern, the can body temperature Tb is higher in the second pattern. Therefore, according to equation (3), the distribution ratio k becomes larger in the second pattern than in the first pattern.

In this way, by making the distribution ratio k larger during the second pattern than during the first pattern, even if the required amount of generated heat is changed, the hot water supplied to each supply point can be The temperature (hot water temperature Th) can be maintained.

[Other examples of combustion period and non-combustion period]
In the embodiment described above, the combustion period and the non-combustion period are the same in the first pattern and the second pattern. In this way, by not changing the combustion period Ton and the non-combustion period Toff, the burden on the control device 100 can be reduced.

Note that the combustion period and the non-combustion period may be different between the first pattern and the second pattern. For example, the ratio (Ton/Toff) of the combustion period Ton to the non-combustion period Toff may be changed by changing at least one of the combustion period Ton and the non-combustion period Toff between the first pattern and the second pattern. .

FIGS. 7 and 8 are diagrams showing examples of combustion period settings. Referring to FIG. 7, the combustion period Ton in the first pattern is set to T1 and the non-combustion period Toff is set to T2, and the combustion period Ton in the second pattern is set to T3 (<T1) and the non-combustion period Toff to T2. May be set. With this setting, the ratio (Ton/Toff) is better when the combustion mechanism 63 is controlled in the first pattern (T1/T2) than when it is controlled in the second pattern (T1/T2). T3/T2). With this setting, it is possible to further suppress the rise in the can body temperature Tb during the second pattern.

Referring to FIG. 8, the combustion period Ton in the first pattern is set to T1 and the non-combustion period Toff is set to T2, and the combustion period Ton in the second pattern is set to T1 and the non-combustion period Toff to T4 (>T2). May be set. With this setting, the ratio (Ton/Toff) is better when the combustion mechanism 63 is controlled in the first pattern (T1/T2) than when it is controlled in the second pattern (T1/T2). T1/T4). With this setting, it is possible to further suppress the rise in the can body temperature Tb during the second pattern. Moreover, when set in this way, the intermittent combustion period C consisting of a combustion period and a non-combustion period is better when the combustion mechanism 63 is controlled in the first pattern (C1) than when the combustion mechanism 63 is controlled in the second pattern. is shorter than when (C2) is controlled. When set in this way, the ignition frequency during the second pattern is reduced, so that the frequency at which the water accumulated in the primary heat exchanger 60 is suddenly warmed when the can body temperature Tb is equal to or higher than the reference temperature T1 can be reduced. This makes it possible to further suppress noise generation.

[How to select water level data]
FIG. 9 is a flowchart for explaining the control process of the bath hot water supply device 10 related to the selection of water level data referred to by the bath entry/exit detection unit 164. The control process shown in FIG. 9 can be executed by the control device 100, for example.

Referring to FIG. 9, upon acquiring the detected value by water level sensor 55 in step S01, control device 100 generates water level data by performing filtering processing using first filter 162a in step S02. The control device 100 further generates water level data by performing filtering processing using the second filter 162b in step S03.

When the water level data is generated by the first filter 162a and the second filter 162b, the control device 100 determines the operation mode of the bath hot water supply device 10 through the processing of steps S04 to S09, and according to the determined operation mode, Select which filter's water level data to use or not to refer to.

Specifically, in step S04, the control device 100 determines whether the bath hot water supply device 10 is in circulation operation. If it is determined that the circulating operation is in progress (YES determination in S04), the control device 100 proceeds to step S13 and does not refer to the water level data.

If it is determined that the bath hot water supply device 10 is not in the circulating operation (NO determination in S04), the control device 100 proceeds to step S05 and determines whether the bath hot water supply device 10 is in the bath water filling operation. . If it is determined that the bath water filling operation is in progress (YES determination in S05), the control device 100 does not refer to the water level data in step S13.

When it is determined that the bath water supply device 10 is not in the bath water filling operation (NO determination in S05), the control device 100 determines whether the current timing is within D seconds from the end of the hot water supply operation in step S06. Determine. If the current timing is within D seconds from the end of the hot water supply operation (YES determination in S06), the control device 100 disables reference to the water level data in step S13. Note that D seconds is determined by preliminary experiments.

On the other hand, if the current timing is not within D seconds from the end of the hot water supply operation (NO determination in S06), the control device 100 determines whether the bath hot water supply device 10 is in the hot water supply operation in step S07. do. When it is determined that the bath hot water supply device 10 is not in hot water supply operation, that is, in a stop mode in which all of the circulation operation, bath water filling operation, and hot water supply operation are stopped (NO determination in S07), the control device 100 , the process proceeds to step S11, and the water level data generated by the first filter 162a is used.

On the other hand, if the bath hot water supply device 10 is in hot water supply operation (YES determination in S07), the control device 100 proceeds to step S08 and determines whether the current timing is the time to switch the number of hot water supply capacity stages. If the current timing is the time of switching the number of hot water supply capacity stages (YES determination in S08), the control device 100 disables reference to the water level data in step S13.

If the current timing is not the time of switching the number of hot water supply capacity stages (NO determination in S08), the control device 100 further determines whether or not intermittent combustion is occurring in step S09. If it is determined that intermittent combustion is occurring (YES in S09), the control device 100 proceeds to step S12 and uses the water level data generated by the second filter 162b.

On the other hand, when it is determined that intermittent combustion is not in progress, that is, continuous combustion is in progress (NO determination in S09), the control device 100 further determines whether the required amount of generated heat Qrq is equal to or less than the amount of heat C in step 10. Determine. The amount of heat C is a determination value that is experimentally set depending on the magnitude of noise generated in the water level data.

When the required amount of generated heat Qrq is larger than the amount of heat C, the control device 100 makes a NO determination in step S10, proceeds to step S13, and disables reference to the water level data.

When the required amount of generated heat Qrq is equal to or less than the amount of heat C (YES in S10), the control device 100 proceeds to step S12 and uses the water level data generated by the second filter 162b.

During circulation operation, during bath water filling operation, within D seconds from the end of hot water supply, during switching of the number of hot water supply capacity stages, and when the required amount of generated heat Qrq is greater than the amount of heat C, even if the second filter 162b with high noise removal performance is used. Too much noise is generated, and the noise components cannot be removed sufficiently. Therefore, in an operating situation where the noise component cannot be sufficiently removed even when the second filter 162b with high noise removal performance is used, the control device 100 is configured to prevent false detection of the bathtub water level. , water level data cannot be referenced.

Operating conditions in which the water level data is less noisy than the above operating conditions include intermittent combustion in hot water supply only operation, and continuous combustion in hot water supply only operation, where the required amount of generated heat Qrq is less than the amount of heat C. included. In this operating situation, the second filter 162b is used to remove noise from the water level data.

The operating situation in which the water level data contains almost no noise includes a stop mode in which all of the hot water supplying operation, the bath water filling operation, and the circulating operation are stopped. In the stop mode, the first filter 162a is used to remove noise from the water level data.

Note that when the can body temperature Tb becomes equal to or higher than the threshold temperature Ts during intermittent combustion in hot water supply independent operation, too much noise is generated even if the second filter 162b with high noise removal performance is used, and the noise components cannot be sufficiently removed. I can't. In this embodiment, during intermittent combustion in hot water supply only operation, when the can body temperature Tb becomes equal to or higher than the reference temperature T1, an occurrence request is made during the combustion period so that the can body temperature Tb does not exceed the threshold temperature Ts. Reduce heat level. As a result, water level data can be referenced even during intermittent combustion in hot water supply independent operation.

As explained above, in the bath water supply device according to the present embodiment, the second filter with high noise removal performance is used during intermittent combustion in the hot water supply only operation. Therefore, the accuracy of detecting the bathtub water level can be improved.

More specifically, the bath water heater according to the present embodiment selectively uses one of a plurality of filters having different noise removal performance and real-time performance depending on the operation mode of the bath water heater. Then, filtering processing is performed on the output of the water level sensor. The plurality of filters include a first filter and a second filter that has higher noise removal performance than the first filter but has lower real-time performance, and the noise generated in the output of the water level sensor is relatively small. The first filter is used in the driving mode, and the second filter is used in the driving mode where noise is relatively large. By using two types of filters depending on the noise generation situation in this way, it is possible to achieve both accuracy and real-time detection of the bathtub water level. As a result, real-time performance can be ensured while maintaining detection accuracy even in the detection of entering and leaving the bath based on changes in the water level of the bathtub, so that it is possible to suppress a decrease in the user's usability.

[Other variations]
In addition, although the embodiment mentioned above showed the example where the can body 6 is comprised by the combustion mechanism 63 which uses petroleum as fuel, the energy source for heating can be made arbitrary.

In addition, in this embodiment, an example was shown in which the water level data with noise removed is used to detect bathing/exiting, but the water level data with noise removed can also be used for other functions such as starting a hot water operation. You may.

The embodiments disclosed this time should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is indicated by the claims rather than the above description, and it is intended that all changes within the meaning and range equivalent to the claims are included.

2 Hot water supply circuit, 4 Circulation circuit, 10 Bath water heater, 53 Temperature sensor, 55 Water level sensor, 60, 61 Primary heat exchanger, 63 Combustion mechanism, 100 Control device, 122 Operation mode setting section, 126 Combustion control section, 162 Noise Removal unit, 162a first filter, 162b second filter, 164 bathing/exiting detection unit.

Claims (5)

A bath water heater,
a hot water supply circuit that has a heat exchanger for hot water supply and heats low-temperature water to supply hot water;
A circulation circuit that includes a reheating heat exchanger and a circulation pump and circulates and heats hot water in the bathtub;
a combustion mechanism that heats the hot water supply heat exchanger and the reheating heat exchanger using a common heat source;
a water level sensor connected to the circulation circuit and detecting the water pressure of the bathtub water;
Equipped with a control device that controls each part,
The operation mode of the bath water heater includes a hot water supply operation, a bath water filling operation and a circulation operation using the circulation circuit,
The control device includes:
selectively controlling the combustion mechanism with continuous combustion in which the combustion mechanism burns continuously and intermittent combustion in which combustion periods and non-combustion periods of the combustion mechanism are repeatedly provided;
When the temperature of the high-temperature water heated by the heat source is lower than a predetermined temperature during the intermittent combustion during the hot water supply independent operation in which the hot water supply operation is performed with the bath water filling operation and the circulation operation stopped, , controlling the combustion mechanism in a first pattern in which the amount of heat generated during the combustion period is a first amount of heat;
During the intermittent combustion during the individual hot water supply operation, when the temperature of the high temperature water is equal to or higher than the predetermined temperature, a second heat amount that causes the amount of heat generated during the combustion period to be a second amount of heat that is smaller than the first amount of heat. controlling the combustion mechanism in a pattern;
A bath water heater that detects a change in a bathtub water level based on a detection value of the water level sensor during the intermittent combustion during the hot water supply independent operation. A ratio of the combustion period to the non-combustion period is greater when the combustion mechanism is controlled in the first pattern than when the combustion mechanism is controlled in the second pattern. 1. The bath hot water supply device according to 1. The intermittent combustion cycle consisting of the combustion period and the non-combustion period is better when the combustion mechanism is controlled in the first pattern than when the combustion mechanism is controlled in the second pattern. The bath water heater according to claim 1 or 2, which is short. Further comprising a temperature sensor that detects the temperature of hot water discharged from the hot water supply heat exchanger,
The bath hot water supply device according to any one of claims 1 to 3, wherein the temperature of the high temperature water is the temperature of the hot water detected by the temperature sensor. The control device includes:
generating water level data by applying filtering processing to the detected value of the water level sensor, detecting a change in the water level in the bathtub based on the generated water level data,
comprising a first filter and a second filter having higher noise removal performance than the first filter, and performing filtering processing using the second filter during the intermittent combustion during the independent hot water supply operation; The bath water supply device according to any one of claims 1 to 4.

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