JP7640832B2 - Heating equipment - Google Patents

Description

The present invention relates to a heating heat source device, and more specifically to a heating heat source device that has a heating function by circulating a heat medium, and a reheating function and a sterilization function by circulating bath water.

JP 2018-54180 A (Patent Document 1) describes a bath system that sterilizes bathtub circulating water using a sterilization lamp, typically a UV (Ultra Violet) lamp for irradiating ultraviolet light. In the bath system, the sterilization lamp is disposed in a reheating circulation path for circulating bathtub water. The bathtub water flowing through the reheating circulation path formed by the operation of the circulation pump is sterilized by ultraviolet light irradiation when the sterilization lamp is turned on.

JP 2018-54180 A

One type of heating heat source device that can be applied to the bath system described above is equipped with a heating function by circulating a heat medium and a reheating function by circulating bath water. In such a heating heat source device, the bath reheating operation is realized using the heat medium that flows through the heating circulation path. Specifically, the reheating operation is performed by the heat medium in the heating circulation path flowing through the liquid-liquid heat exchanger via the control valve, heating the bath water flowing through the reheating circulation path. Therefore, when the reheating operation is not being performed while the heat medium is flowing through the heating circulation path due to the heating operation, the supply of the heat medium to the liquid-liquid heat exchanger is cut off by closing the control valve.

On the other hand, in the heating heat source device, it is possible to perform an operation (so-called hot dash operation) in which a heat medium at a higher temperature than normal is supplied to the heating terminal within a specified time after the start of heating operation to quickly warm up the heating terminal. In hot dash operation, the control valve is opened to ensure the flow rate of the heating circulation path.

Therefore, if hot dash operation is started while sterilization operation is being performed, the heating circulation path is formed with the control valve open. In this case, the heated heat medium is supplied to the liquid-liquid heat exchanger, so the bath water flowing through the reheating circulation path is heated. In other words, if sterilization operation and hot dash operation are performed simultaneously, the reheating operation is essentially performed even though heating of the bath water is not intended, and as a result, there is a risk that unintended high-temperature water will be output to the bathtub.

The present invention has been made to solve these problems, and the object of the present invention is to prevent unintended high-temperature water from being output into the bathtub while the sterilization process is being performed in a heating heat source device that has a heating function by circulating a heat medium, a reheating function by circulating bath water, and a sterilization function.

In one aspect of the present invention, the heating heat source device includes a heat medium circulation path, a heat source, a control valve, a heat exchanger, a reheating circulation path, a sterilization lamp, and a controller. The heat medium circulation path is formed when the first circulation pump is operated, and circulates and supplies a liquid heat medium to a heating terminal connected to the heating heat source device. The heat source heats the heat medium. The control valve is arranged so as to be included in the heat medium circulation path. The heat exchanger has a primary side path through which the heat medium flows when the control valve is opened. The reheating circulation path is formed when the second circulation pump is operated, and returns bath water from the bathtub to the bathtub after it flows through the secondary side path of the heat exchanger. The sterilization lamp is arranged so as to be included in the reheating circulation path, and irradiates light rays in a wavelength range that has a sterilization effect when lit. In a sterilization operation for sterilizing bath water flowing through the reheating circulation path using a sterilization lamp, the controller operates the second circulation pump, turns on the sterilization lamp, and controls the second circulation pump, the control valve, and the sterilization lamp to close the control valve.

According to the present invention, in a heating heat source device that has a heating function by circulating a heat medium, a reheating function by circulating bath water, and a sterilization function, it is possible to prevent unintended high-temperature water from being output into the bathtub while the sterilization process is being performed.

1 is a schematic configuration diagram of a heating heat source device according to an embodiment. FIG. 2 is a block diagram for explaining a flow path of a heat medium in a heating circuit. 5 is a flowchart illustrating opening and closing control of a control valve in a heating heat source device according to the present embodiment. FIG. 4 is a conceptual waveform diagram for illustrating opening and closing control of a control valve in the heating heat source device according to the present embodiment. 10 is a flowchart illustrating an example of HD control during heating operation of a heating heat source device. 10 is a flowchart illustrating another example of HD control during heating operation of a heating heat source device. 10 is a flowchart illustrating a modified example of opening and closing control of a control valve in a heating heat source device according to the present embodiment.

The following describes in detail an embodiment of the present invention with reference to the drawings. Note that the same or corresponding parts in the drawings are given the same reference numerals and their description will not be repeated.

FIG. 1 is a schematic configuration diagram of a heating heat source device 100 according to an embodiment.
Referring to Fig. 1, the heating heat source device 100 includes a hot water supply circuit 101, a reheating circuit 102, a heating circuit 103, and a controller 300. The hot water supply circuit 101 is configured to output hot water at an appropriate temperature controlled to a set temperature when a hot water tap such as a faucet 105 or a shower (not shown) is opened. The reheating circuit 102 is configured to heat and circulate hot water in a bathtub (not shown). The heating circuit 103 is configured to circulate and supply high-temperature water, which is a liquid heat medium, to a heating terminal (not shown) device connected to the heating heat source device 100. The controller 300 is configured, for example, by a microcomputer. The controller 300 corresponds to one embodiment of a "controller".

The reheating circuit 102 is configured to form a reheating circulation path for heating and circulating the hot water in the bathtub between the bathtub water inlet 191 and the bathtub water outlet 192. The bathtub water inlet 191 and the bathtub water outlet 192 are each connected via piping to an opening provided in a bathtub adapter (not shown) placed in the bathtub.

A heating terminal (not shown) that receives the heat medium from the heating circuit 103 is connected between the heating return port 302 and the heating output port (low temperature) 304, or between the heating return port 302 and the heating output port (high temperature) 306.

The configurations of the hot water supply circuit 101, the reheating circuit 102, and the heating circuit 103 will be explained below in order.

The hot water supply circuit 101 includes a primary heat exchanger 11a, a secondary heat exchanger 21a, and a combustion burner 30a housed in the boiler body 10. The hot water supply circuit 101 further includes a water inlet pipe 50, a bypass pipe 60, and a hot water outlet pipe 70.

Tap water or the like is supplied to the water inlet pipe 50. A bypass pipe 60 is placed between the water inlet pipe 50 and the hot water outlet pipe 70. A distribution valve 80 is interposed and connected to the water inlet pipe 50 to control the water diversion to the bypass pipe 60. Depending on the opening of the distribution valve 80, a portion of the water supply is diverted from the water inlet pipe 50 to the bypass pipe 60.

Furthermore, a temperature sensor 110 and a flow rate sensor 150 are disposed in the water inlet pipe 50. The temperature sensor 110 detects the inlet water temperature. The flow rate sensor 150 is disposed downstream (on the can body side) of the distribution valve 80, and detects the flow rate passing through the can body 10 (can body flow rate).

The water in the water inlet pipe 50 is first preheated by the secondary heat exchanger 21a, and then primarily heated in the primary heat exchanger 11a. Hot water heated to a predetermined temperature by the primary heat exchanger 11a and the secondary heat exchanger 21a is discharged from the hot water outlet pipe 70.

The hot water outlet pipe 70 is connected to the bypass pipe 60 at the junction 75. Therefore, from the heating heat source device 100, hot water at an appropriate temperature, which is a mixture of high-temperature water output from the boiler body 10 and low-temperature water from the bypass pipe 60, is supplied to a designated hot water supply point such as a hot water tap in the kitchen or bathroom, or a hot water supply circuit to the bath (not shown).

The hot water outlet pipe 70 is provided with a flow rate adjustment valve 90 and temperature sensors 120, 130. The temperature sensor 120 is located upstream (on the boiler body side) of the junction 75 of the hot water outlet pipe 70 with the bypass pipe 60, and detects the hot water temperature output from the boiler body 10. The temperature sensor 130 is located downstream (on the hot water outlet side) of the junction 75, and detects the hot water temperature after it is mixed with water from the bypass pipe 60. The flow rate adjustment valve 90 is provided to control the hot water outlet flow rate.

In the can body 10, the combustion burner 30a outputs a mixture of fuel gas and combustion air supplied by the blower fan 40. The mixture is ignited by an ignition device (not shown), causing the fuel gas to burn and generating a flame. The combustion heat generated by the flame from the combustion burner 30a is provided to the primary heat exchanger 11a and secondary heat exchanger 21a within the can body 10.

The primary heat exchanger 11a heats the inlet water by heat exchange using the sensible heat (combustion heat) of the combustion gas from the combustion burner 30a. The secondary heat exchanger 21a heats the water flowing through it by using the latent heat of the combustion exhaust gas from the combustion burner 30a. An exhaust path 15 is provided downstream of the combustion gas flow direction of the can body 10 to discharge the combustion exhaust gas after heat exchange. In this way, in the can body 10, the primary heat exchanger 11a and the secondary heat exchanger 21a heat the water supplied from the water inlet pipe 50 by the amount of heat generated by combustion in the combustion burner 30a.

A main gas solenoid valve 32, a gas proportional valve 33, and capacity switching valves 35a to 35c are arranged in the gas supply pipe 31 to the combustion burner 30a. The main gas solenoid valve 32 has the function of turning on and off the supply of fuel gas to the combustion burner 30a. The gas flow rate in the gas supply pipe 31 is controlled according to the opening degree of the gas proportional valve 33. The capacity switching valves 35a to 35c are controlled to open and close in order to switch the number of burners (number of burners) to which fuel gas is supplied among the multiple combustion burners 30a.

Next, we will explain the configuration related to supplying hot water to the bathtub in the heating heat source device 100, including the reheating circuit 102. Note that in the following, supplying hot water to the bathtub will be referred to as "pouring hot water," while supplying hot water to hot water taps other than the bathtub (such as the faucet 105) will be referred to simply as "supplying hot water."

The heating heat source device 100 further includes a hot water supply pipe 180 that branches off from the hot water outlet pipe 70 to supply hot water to a bathtub (not shown). The hot water supply pipe 180 branches off from the hot water outlet pipe 70 via a flow control valve 90. Furthermore, a hot water supply opening/closing valve 210 and a check valve 220 are interposed and connected to the hot water supply pipe 180. The hot water supply pipe 180 is connected to the bath return pipe 194, which will be described later, at a junction 185.

By controlling the opening and closing of the hot water supply on-off valve 210 by the controller 300, it is possible to control the opening and closing of a path for supplying hot water from the hot water supply circuit 101 to the bathtub. A flow rate sensor 215 for detecting the hot water supply flow rate is arranged in correspondence with the hot water supply on-off valve 210.

The reheating circuit 102 includes a bath return pipe 194, a bath supply pipe 195, a reheating circulation pump 400, a bath heat exchanger 410, and a UV unit 600.

The bath return pipe 194 connects the bath water intake port 191 and one end of the secondary path of the bath heat exchanger 410. The reheating circulation pump 400 is interposed and connected to the bath return pipe 194. The other end (bathtub side) of the secondary path of the bath heat exchanger 410 is connected to the bath water outlet port 192 by the bath supply pipe 195.

During reheating operation, the reheating circulation pump 400 operates to draw bath water from the bath water intake port 191 into the heating heat source device 100. Then, a reheating circulation path is formed in which the drawn-in hot water is returned to the bath from the bath water outlet port 192 via the bath return pipe 194, the reheating circulation pump 400, the bath heat exchanger 410 (secondary side path), and the bath supply pipe 195. In the reheating circulation path, temperature sensors 372 and 374 are provided on the input side and output side of the bath heat exchanger 410, respectively. The temperature sensors 372 and 374 are, for example, thermistors. Hereinafter, the temperature detected by the temperature sensor 374 arranged on the output side of the bath heat exchanger 410 is also referred to as the outlet temperature Tch.

During reheating operation, the control valve 330 of the heating circuit 103 is opened. This causes the heat medium heated in the heating circuit 103 (described later) to flow through the primary path of the bath heat exchanger 410. As a result, the hot water in the reheating circulation path passing through the secondary path of the bath heat exchanger 410 is heated by liquid-liquid heat exchange with the heat medium passing through the primary path of the bath heat exchanger 410, thereby raising the water temperature in the bathtub.

The control valve 330 can typically be configured as a thermal valve that can be controlled to open and close. Alternatively, the control valve 330 can be configured as a flow adjustment valve whose opening can be controlled to control the flow rate of the heat medium passing through the bath heat exchanger 410 (primary side path).

Furthermore, the bath return pipe 194 is connected to the hot water supply pipe 180 at the junction 185. As a result, when the hot water supply opening/closing valve 210 is opened, hot water from the hot water supply circuit 101 is supplied to the junction 185 via the hot water supply pipe 180. During hot water supply operation, the reheating circulation pump 400 is stopped, so the supplied hot water is supplied into the bathtub from both the bathtub water intake port 191 and the bathtub water discharge port 192 via the bath return pipe 194 and the bath supply pipe 195, respectively. This forms a hot water supply path from the hot water supply circuit 101 to the bathtub.

The UV unit 600 is arranged in the bath return pipe 194 so that the bath water flows through it. The UV unit 600 has a built-in UV lamp 610 for irradiating the bath water with ultraviolet rays. That is, the UV lamp 610 is configured to irradiate light (ultraviolet rays) in a wavelength range that has a sterilizing effect when turned on, and corresponds to one embodiment of a "sterilization lamp."

The UV lamp 610 is arranged so as to be included in the reheating circulation path into which bath water is introduced by the operation of the reheating circulation pump 400. The bath water passing through the UV unit 600 is sterilized by ultraviolet light irradiation when the UV lamp 610 is turned on, thereby reducing the number of germs. The UV unit 600 incorporating the UV lamp 610 may be arranged anywhere on the reheating circulation path. In addition, in this embodiment, the UV lamp 610 is exemplified as a "sterilization lamp", but the "sterilization lamp" can also be composed of a fluorescent lamp, a light-emitting diode (LED), etc. other than the UV lamp 610, as long as it irradiates light in a wavelength range that has a sterilizing effect when turned on.

In the heating heat source device 100 according to this embodiment, by disposing the UV unit 600, it is possible to carry out a sterilization process on the bath water flowing through the reheating circulation path. The sterilization process can be carried out by operating the reheating circulation pump 400 and turning on the UV lamp 610 regardless of whether or not heating is being performed by the bath heat exchanger 410, i.e., even when not in reheating operation.

Next, the heating circuit 103 in the heating heat source device 100 will be described.
During heating operation, the heating circuit 103 is configured to form a circulation path for a heat medium (typically, high-temperature water) between the heating return port 302 and the heating output port (low temperature) 304, and between the heating return port 302 and the heating output port (high temperature) 306, respectively.

A heating terminal (not shown) is connected between the heating return port 302 and the heating output port (low temperature) 304. The low temperature heating terminal is, for example, a hot water panel for floor heating through which the heat medium from the heating circuit 103 flows. Similarly, a heating terminal (not shown) is connected between the heating return port 302 and the heating output port (high temperature) 306. The high temperature heating terminal is, for example, a room heater that outputs hot air heated by the heat medium from the heating circuit 103.

The heating circuit 103 includes a primary heat exchanger 11b, a secondary heat exchanger 21b, and a combustion burner 30b. The primary heat exchanger 11b, the secondary heat exchanger 21b, and the combustion burner 30b are housed in a common boiler body 10 with the primary heat exchanger 11a, the secondary heat exchanger 21a, and the combustion burner 30a of the hot water supply circuit.

The primary heat exchanger 11b heats the incoming water by heat exchange using the sensible heat (combustion heat) of the combustion gas from the combustion burner 30b. The secondary heat exchanger 21b heats the water flowing through it by heat exchange using the latent heat of the combustion exhaust gas from the combustion burner 30b. The number of burners (number of burners being burned) to which fuel gas is supplied is switched among the multiple combustion burners 30b by controlling the opening and closing of the capacity switching valves 36a and 36b. Fuel gas is supplied to the combustion burner 30b via the gas supply pipe 31, the main gas solenoid valve 32, and the gas proportional valve 33, which are shared with the combustion burner 30a.

Furthermore, the heating circuit 103 includes a heating circulation pump 310, a heating expansion tank 320, a control valve 330, pipes 350, 360, 370, 380, and 390, a terminal thermal valve 305, and temperature sensors 382 and 384.

One end of the piping 350 is connected to one end (inlet side) of the primary heat exchanger 11b. The other end of the piping 350 is connected to multiple heating output ports (low temperature) 304 via multiple terminal thermal valves 305.

The pipe 360 is disposed between the other end (outlet side) of the primary heat exchanger 11b and the pipe 380. As described below, the pipe 360 is provided with a bath heat exchanger 410 and a control valve 330. The pipes 360 and 370 branch off on the same side (outlet side) of the primary heat exchanger 11b, and the pipe 370 connects the other end of the primary heat exchanger 11b to the heating output port 306 (high temperature).

The piping 380 connects the heating return port 302 to one end (inlet side) of the secondary heat exchanger 21b. The piping 390 connects the heating expansion tank 320 to the other end (outlet side) of the secondary heat exchanger 21b.

The intake port 311 of the heating circulation pump 310 is connected to the heating expansion tank 320. The discharge port 312 of the heating circulation pump 310 is connected to the branch portion 355 of the piping 350.

The heating expansion tank 320 temporarily stores the heat medium circulating through the heating circuit 103. When the water level in the heating expansion tank 320 drops, water can be supplied from the pipe 51 by opening the water supply valve 327. When the water level rises, the heat medium can be discharged from the overflow tank 328 to the drain plug 106 via the pipe 325. Although not shown, drain (condensed water) generated inside the can body 10 is stored in a drain tank (not shown) and discharged to the outside after neutralization treatment.

A control valve (typically a thermal valve) 330 that is controlled to open and close in response to a command from the controller 300 is interposed and connected to the piping 360. When the control valve 330 is open, the heat medium heated by the primary heat exchanger 11b is divided into a path that is output to the heating output port 306 (high temperature) by the piping 370 and a path that is circulated via the piping 360. Therefore, when the control valve 330 is open, a path is further formed that circulates the heat medium output from the primary heat exchanger 11b to the secondary heat exchanger 21b via the piping 360, the bath heat exchanger 410 (primary side path), the junction 385 and the piping 380. On the other hand, when the control valve 330 is closed, the heat medium output from the primary heat exchanger 11b is supplied only to the piping 370 without passing through the bath heat exchanger 410 (primary side path).

A temperature sensor 384 is disposed on the output side of the primary heat exchanger 11b to detect the output temperature from the tank body 10 in the heating circuit 103, i.e., the heat medium temperature after heating. On the other hand, a temperature sensor 382 is disposed in the heating expansion tank 320 to detect the heat medium temperature in the tank. The low-temperature side heat medium temperature detected by the temperature sensor 382 corresponds to the temperature of the heat medium supplied from the heating outlet (low temperature) 304. The temperature sensors 382 and 384 are, for example, thermistors.

The controller 300 receives output signals (detection values) from each sensor and user operations, and issues control commands to each device to control the overall operation of the heating heat source device 100. User operations include an operation on/off command for the heating heat source device 100 and a set water temperature command. Furthermore, in the heating heat source device 100 equipped with a UV unit 600, user operations include an on/off command for sterilization operation using the UV lamp 610. Regarding the sterilization operation, a timer operation function can be provided that specifies the sterilization end time, assuming that the remaining bath water will be used for laundry the next morning. In this case, the user operations include the sterilization end time. For example, these user operations are input to a remote controller (not shown).

The controller 300 sets the illumination time of the UV lamp 610 for sterilization according to user operation. In a sterilization operation with a specified sterilization end time (timer sterilization operation), the illumination time of the UV lamp 610 is automatically set by the controller 300 so that the number of germs in the bath water is below a predetermined value at the sterilization end time.

The control commands include opening/closing and opening degree commands for each valve, commands for the combustion burners 30a, 30b (combustion on/off and heat generation amount), and on/off commands for the heating circulation pump 310. The operation on/off commands include on/off commands for the hot water supply operation and hot water pouring operation by the hot water supply circuit 101, the reheating operation by the reheating circuit 102, and the heating operation by the heating circuit 103. Regarding the heating operation, the heating operation in the heating heat source device 100 may be automatically turned on in response to an on command to the heating terminal.

During hot water supply operation and hot water pouring operation, low-temperature water in the water inlet pipe 50 is heated by combustion in the combustion burner 30a of the hot water supply circuit 101 and output to the hot water outlet pipe 70. The controller 300 calculates the required amount of heat P* to be generated by the combustion burner 30a during hot water supply operation and hot water pouring operation. For example, the required amount of heat P* is calculated so that the detected value of the boiler body outlet temperature is controlled to a target value. The target value of the boiler body outlet temperature can be set based on the set temperature during hot water supply operation and hot water pouring operation set by the user and the flow division ratio of the bypass pipe 60 (opening degree of the distribution valve 80).

During reheating operation and heating operation, the heat medium circulating through the circulation path formed by driving the heating circulation pump 310 is heated by combustion in the combustion burner 30b. The controller 300 calculates the required amount of heat P* to be generated by the combustion burner 30b so that the detection value of the output temperature of the primary heat exchanger 11b detected by the temperature sensor 384 (temperature sensor 384) is controlled to the target value.

The controller 300 calculates the amount of gas to be supplied to the combustion burners 30a, 30b according to the calculated required heat generation amount P* in each of the hot water supply operation, hot water supply operation, heating operation, and reheating operation. Furthermore, the controller 300 determines the combination of the number of burners to be fired and the gas flow rate among the combustion burners 30a, 30b that will realize this amount of gas to be supplied, and controls the opening degree of the gas proportional valve 33 and the opening and closing of the capacity switching valves 35a-35c, 36a, 36b so that the determined number of burners to be fired and the gas flow rate are realized. Furthermore, the controller 300 controls the rotation speed of the blower fan 40 so that the ratio (air-fuel ratio) of the amount of air blown by the blower fan 40 to the calculated amount of gas to be supplied becomes a predetermined value (e.g., ideal air-fuel ratio).

During sterilization operation, the controller 300 generates a control signal to instruct the reheating circulation pump 400 to operate and stop, and a control signal to instruct the UV lamp 610 to turn on and off. The reheating circulation pump 400 operates or stops according to the control signal. The UV lamp 610 turns on or off depending on whether or not the power supply voltage is supplied according to the control signal.

Next, the current path in the heating circuit 103 of the heating heat source device 100 will be described in more detail.
FIG. 2 is a block diagram for explaining the flow path of the heat medium in the heating circuit 103.

Referring to FIG. 2, in the heating circuit 103, the heating circulation pump 310 and the combustion burner 30b are operated to form the heat medium circulation path 510 described below, thereby circulating and heating the heat medium (hot water). In other words, the heating circulation pump 310 corresponds to one embodiment of the "first circulation pump."

By operating the heating circulation pump 310, an intake path is formed that runs from the heating return port 302 through the piping 380, the secondary heat exchanger 21b, the piping 390, and the heating expansion tank 320 to the intake port 311 of the heating circulation pump 310. The heat medium sucked into the heating expansion tank 320 by the heating circulation pump 310 is output from the discharge port 312 to the branching portion 355 of the piping 350.

The heat medium discharged from the heating circulation pump 310 is branched at the branching point 355 of the piping 350 into an output path leading to the terminal thermal valve 305 and the heating output port (low temperature) 304, and a heating path passing through the primary heat exchanger 11b that receives heat from the combustion burner 30b. The heating path includes an output path that outputs the heat medium from the heating output port (high temperature) 306 via the piping 370 after passing through the primary heat exchanger 11b, and a return path that passes through the primary heat exchanger 11b, the piping 360, the bath heat exchanger 410 (primary side path 411), the junction 385, the piping 380, the secondary heat exchanger 21b, and the piping 390, and then leads back to the heating expansion tank 320. The return path is formed when the control valve 330 is open, but is not formed when the control valve 330 is closed.

During heating operation, the heating circulation pump 310 and the combustion burner 30b are operated to form a heat medium circulation path 510, and the high-temperature heat medium that has passed through the primary heat exchanger 11b is supplied to the heating terminal connected to the heating output port 306 (high temperature). On the other hand, the heat medium in the heating expansion tank 320 is supplied to the heating terminal connected to the heating output port 304 (low temperature). In this way, the heat medium is supplied from the heating heat source device 100 (heating circuit 103) to the heating terminal (not shown). The combustion burner 30b, the primary heat exchanger 11b, and the secondary heat exchanger 21b constitute a "heat source."

During heating operation, the control valve 330 may be in either an open state or a closed state, but by opening the control valve 330 to form the return path, the flow rate of the heat medium output to the heating terminal is reduced, while the flow rate of the heat medium passing through the heat exchanger (secondary heat exchanger 21b and primary heat exchanger 11b) is increased. Therefore, by opening the control valve 330 to form the return path, the temperature of the heat medium can be quickly increased. For example, in the heating heat source device 100, a so-called hot dash control (hereinafter also referred to as HD control) can be performed to supply a heat medium at a higher temperature than normal (i.e., after the above-mentioned certain time has passed) to a specific heating terminal until a certain time has passed since the start of heating operation, in order to quickly warm up the heating terminal. At this time, the above-mentioned operation mode in which the control valve 330 is opened can be applied. For example, when HD control is performed, the temperature of the heat medium supplied from the heating output port to the low-temperature heating terminal is increased from about 60°C under normal conditions to about 70°C. HD control corresponds to "quick heating operation." HD control is not normally applied to high-temperature heating terminals.

In the reheating circuit 102, the reheating circulation pump 400 operates to form a reheating circulation path 520 between the bathtub 190 and the bathtub, including the secondary path 412 of the bath heat exchanger 410. During reheating operation, the control valve 330 is opened to form the heat medium circulation path 510, and the bath water flowing through the reheating circulation path 520 is heated by liquid-liquid heat exchange between the primary path 411 and secondary path 412 of the bath heat exchanger 410.

Even when the sterilization operation is being performed, the reheating circulation pump 400 operates to form the reheating circulation path 520. Furthermore, the UV lamp 610 built into the UV unit 600 is turned on to sterilize the bath water flowing through the reheating circulation path 520.

Here, in the heating heat source device 100, when the sterilization operation is performed, HD control is started, and while the heating of the bath water is not assumed, there are cases where the control valve 330 is open and the heating circulation pump 310 and the combustion burner 30b are operated to form the heat medium circulation path 510. In this case, the heated heat medium flows through the primary side path 411 of the bath heat exchanger 410, and the bath water flowing through the reheating circulation path 520 is heated by heat exchange between the primary side path 411 of the bath heat exchanger 410 and the secondary heat exchanger 412. In other words, in cases where the sterilization operation and HD control are performed simultaneously, the reheating operation is essentially performed even though the heating of the bath water is not assumed, and as a result, there is a risk that unintended high-temperature water will be output to the bathtub 190.

Therefore, in the heating heat source device 100 according to this embodiment, the control valve 330 is closed and the opening of the control valve 330 is prohibited when the sterilization operation is being performed according to the control process shown in FIG. 3. However, even during the sterilization operation, the control valve 330 is opened during the reheating operation.

Figure 3 is a flowchart explaining the opening and closing control of the control valve 330 in the heating heat source device 100 according to this embodiment. The control process according to the flowchart shown in Figure 3 is repeatedly executed by the controller 300 shown in Figure 1.

Referring to FIG. 3, in step S01, the controller 300 determines whether or not a sterilization operation is being performed. As described above, the determination in step S01 can be made based on a user's switch operation on a remote controller (not shown).

When the sterilization operation is in progress (YES in S01), the controller 300 advances the process to step S02 and supplies power supply voltage to the UV lamp 610, thereby turning on the UV lamp 610.

In step S03, the controller 300 determines whether or not the reheating operation is in progress. As described above, the determination in step S03 can be made based on the user's switch operation on the remote controller (not shown).

When the controller 300 is in sterilization operation and reheating operation (YES in S03), the controller 300 advances the process to step S08 and opens the control valve 330. On the other hand, when the controller 300 is in sterilization operation and reheating operation is not being performed (NO in S03), the controller 300 advances the process to step S04 and closes the control valve 330. That is, the controller 300 closes the control valve 330 during sterilization operation, except during reheating operation. As shown in FIG. 2, by closing the control valve 330, in the heat medium circulation path 510, the heat medium that has passed through the primary heat exchanger 11b passes through the piping 360, the bath heat exchanger 410 (primary side path 411), the junction 385, the piping 380, the secondary heat exchanger 21b, and the piping 390, and the return path to the heating expansion tank 320 again is not formed. Therefore, even if the heating circulation pump 310 and the combustion burner 30b are operated to form the heat medium circulation path 510 during sterilization operation, the bath water flowing through the reheating circulation path 520 can be prevented from being heated by liquid-liquid heat exchange between the primary side path 411 and the secondary side path 412 of the bath heat exchanger 410.

Returning to step S01, when the sterilization operation is not being performed (when the determination in S01 is NO), the controller 300 stops the supply of power supply voltage to the UV lamp 610 in step S06, thereby turning off the UV lamp 610. Furthermore, the controller 300 allows the control valve 330 to be opened in step S06. In other words, the controller 300 allows the formation of the return path in the heat medium circulation path 510.

In step S07, the controller 300 determines whether or not the reheating operation is in progress. As described above, the determination in step S07 can be made based on the user's switch operation on the remote controller (not shown).

When reheating operation is in progress (YES in S07), the controller 300 opens the control valve 330 in step S08. On the other hand, when reheating operation is not in progress (NO in S07), the controller 300 advances the process to step S09 and determines whether HD control is being applied. HD control is performed at a predetermined time after the start of heating operation. The determination in step S09 can be made based on whether the elapsed time from the start of heating operation has exceeded the predetermined time.

When HD control is being applied (YES in S09), the controller 300 opens the control valve 330 in step S08. On the other hand, when HD control is not being applied (NO in S09), the controller 300 closes the control valve 330 in step S10.

Figure 4 is a conceptual waveform diagram for explaining the opening and closing control of the control valve 330 in the heating heat source device 100 according to the present embodiment. Figure 4 shows the operating waveforms of the control valve 330 depending on whether or not reheating operation, sterilization operation, and HD control are performed.

Referring to FIG. 4, at time t0, the heating heat source device 100 is performing reheating operation, and is not performing heating operation. At this time, in the reheating circuit 102, the reheating circulation path 520 (FIG. 2) is formed by operating the reheating circulation pump 400 (ON). In the heating circuit 103, the heat medium circulation path 510 (FIG. 2) is formed by operating the heating circulation pump 310 and the combustion burner 30b with the control valve 330 open.

When sterilization operation is started according to user operation at time t1 during reheating operation, in the reheating circuit 102, the UV lamp 610 is turned on with the reheating circulation pump 400 operating. The illumination time of the UV lamp 610 is set according to user operation. Since reheating operation is in progress at time t1, the control valve 330 in the heating circuit 103 is not closed and is kept open. After time t1, in the reheating circulation path 520, the bath heat exchanger 410 heats the bath water and the UV unit 600 sterilizes the bath water in parallel.

When the reheating operation is stopped at time t2, the heating heat source device 100 performs the sterilization operation alone. Therefore, the control valve 330 is closed. In addition, in response to the stop of the reheating operation, the operation of the heating circulation pump 310 and the combustion burner 30b is stopped in the heating circuit 103, and the heat medium circulation path 510 is not formed.

When the heating operation is started at time t3 during the sterilization operation, the HD control is executed until time t5, when a certain time has elapsed since the start of the heating operation. Therefore, from time t3 when the HD control is started to time t4 when the sterilization operation ends, the HD control is executed simultaneously with the sterilization operation. During the period from time t3 to time t4, in the heating circuit 103, the heating circulation pump 310 and the combustion burner 30b are operated to form the heat medium circulation path 510, but the control valve 330 is closed. Therefore, the formation of a return path through which the heat medium that has passed through the primary heat exchanger 11b reaches the heating expansion tank 320 via the bath heat exchanger 410 (primary side path 411) is prevented. This makes it possible to suppress the bath water flowing through the reheating circulation path 520 from being heated by liquid-liquid heat exchange in the bath heat exchanger 410.

When the sterilization operation ends at time t4, the control valve 330 is permitted to be opened, and the control valve 330 is opened. In the heating circuit 103, the heat medium circulation path 510 is formed with the control valve 330 open. In the reheating circuit 102, the reheating circulation pump 400 is stopped in response to the end of the sterilization operation, and the reheating circulation path 520 is not formed.

When HD control ends at time t5, the control valve 330 is closed in the heat medium circulation path 510, and normal heating operation is performed. When the heating operation ends, the heating circulation pump 310 and the combustion burner 30b are stopped, and the heat medium circulation path 510 is not formed.

When the heating operation is started again at time t6 while the heating operation is stopped, HD control is executed until time t9, when a certain time has elapsed since the start of the heating operation. At this time, since the sterilization operation is not being executed, the heating circuit 103 forms the heat medium circulation path 510 with the control valve 330 open.

When the timer sterilization operation starts at time t7 after the start of HD control, the lighting time of the UV lamp 610 is set intermittently and repeatedly until the sterilization end time arrives. A set of off time and on time is considered as one control cycle, and multiple control cycles are set by counting backwards so that the last lighting time ends at the sterilization end time.

When the illumination time of the UV lamp 610 is set while HD control is being applied, the control valve 330 is temporarily closed during the illumination time of the UV lamp 610 (the period from time t7 to time t8). Since the formation of the return path described above is prevented in the heat medium circulation path 510, the bath water flowing through the reheating circulation path 520 can be prevented from being heated by heat exchange in the bath heat exchanger 410.

On the other hand, because HD control is performed with the control valve 330 closed during sterilization operation, there is a concern that a rapid increase in the heat medium temperature may be suppressed. Therefore, in this embodiment, when HD control is applied, the target temperature of the can body outlet temperature Tht (can body target temperature Tht*) is changed according to the state of the control valve 330. In other words, the required amount of heat generated by the combustion burner 30b P* is changed according to the state of the control valve 330.

Figure 5 is a flowchart illustrating an example of HD control during heating operation of a heating heat source device. The control process according to the flowchart shown in Figure 5 is repeatedly executed by the controller 300 while the heating operation is on.

Referring to FIG. 5, in step S21, the controller 300 determines whether the HD control start condition is satisfied. The HD control start condition is satisfied, for example, when the heating operation starts. Note that even when the heating operation starts, if the hot water temperature in the heating expansion tank 320 detected by the temperature sensor 382 is higher than a predetermined temperature, step S21 may be determined as NO.

When the conditions for starting HD control are not met (NO in S21), the controller 300 performs normal heating operation. In this case, the target temperature Tht* of the heater body is set to a predetermined value T0. For example, T0 is set so that the temperature of the heat medium output from the heating output port (low temperature) 304 is about 60°C.

When the HD control start condition is met (YES in S21), the controller 300 advances the process to S22 and determines whether the control valve 330 is open or closed. If the control valve 330 is closed (YES in S22), the controller 300 advances the process to S23 and determines whether opening of the control valve 330 is permitted. If the control process according to the flowchart shown in FIG. 3 closes the control valve 330 and prohibits opening of the control valve 330 (S04), a NO determination is made in step S23.

On the other hand, if the control valve 330 is open (NO in S22), the controller 300 sets the target temperature Tht* of the boiler body to the default value T1 for HD control (Tht*=T1) in step S26. For example, T1 is set so that the temperature of the heat medium output from the heating output port (low temperature) 304 is about 80°C.

On the other hand, when the control valve 330 is closed and the opening of the control valve 330 is prohibited (NO in S23), the controller 300 proceeds to step S27 and sets the target can body temperature Tht* to a predetermined value T2 higher than the default value T1 (T1<T2). For example, T2 is set so that the temperature of the heat medium output from the heating output port (low temperature) 304 is about 83°C. In this way, the target can body temperature Tht* in HD control is set to T1 or T2 according to whether the control valve 330 is open or closed in steps S26 and S27. In the process of FIG. 5, when the control valve 330 is closed, the target can body temperature Tht* in HD control is increased above the default value T1 to increase the amount of heat from the heat source (combustion burner 30b, primary heat exchanger 11b, and secondary heat exchanger 21b).

In step S28, the controller 300 determines whether the condition for terminating HD control is met. For example, in step S28, it is determined whether the elapsed time from the HD control circuit has exceeded a predetermined time.

The controller 300 repeatedly executes the processes of steps S22 to S27 until the time elapsed since the start of HD control exceeds a predetermined time (NO in S28). On the other hand, if the time elapsed since the start of HD control exceeds the predetermined time (YES in S28), the controller 300 proceeds to the process of step S29 and ends HD control. Until the current heating operation is turned off, a NO judgment is made in step S21 in the flowchart of FIG. 5, and the target tank temperature Tht* is set to T0 (S25). This makes it possible to apply HD control only at the start of heating operation.

Figure 6 is a flowchart explaining another example of HD control during heating operation of a heating heat source device. The control process according to the flowchart shown in Figure 6 is repeatedly executed by the controller 300 while the heating operation is on. The flowchart in Figure 6 replaces step S27 in the flowchart in Figure 5 with step S30.

In FIG. 6, when the control valve 330 is closed and the opening of the control valve 330 is prohibited (NO in S23), the controller 300 proceeds to step S30 and sets the target can body temperature Tht* to a predetermined value T3 lower than the default value T1 (T0<T3<T1). For example, T3 is set so that the temperature of the heat medium output from the heating output port (low temperature) 304 is about 77°C. In this way, steps S26 and S30 set the target can body temperature Tht* in HD control to T1 or T3 depending on whether the control valve 330 is open or closed.

In HD control, the amount of heat given from the combustion burner 30b to the primary heat exchanger 11b increases, so when the control valve 330 is closed, the flow rate of the primary heat exchanger 11b decreases, and there is a concern that the can body outlet temperature Tht will rise too much, forcing the combustion to be stopped frequently. Therefore, in the process of FIG. 6, when the control valve 330 is closed, the can body target temperature Tht* in HD control is lowered below the default value T1, thereby reducing the amount of heat from the heat source (combustion burner 30b, primary heat exchanger 11b, and secondary heat exchanger 21b).

As described above, according to the heating heat source device of this embodiment, in an operating mode in which a reheating circulation path is formed without heating the bath water, by closing the control valve 330, the heat medium heated by the heat source does not pass through the bath heat exchanger 410 (primary side path) even if a heat medium circulation path is formed during that operating mode. As a result, the bath water flowing through the reheating circulation path is prevented from being heated by heat exchange in the bath heat exchanger 410, and unintended high-temperature bath water is prevented from being output to the bathtub.

In the above embodiment, the sterilization operation for sterilizing bath water was described as an operation mode for forming a reheating circulation path without heating the bath water, but the operation mode is not limited to the sterilization operation. For example, the operation mode is also applied to an operation in which bath water mixed with tiny air bubbles is sprayed into the bathtub (hereinafter also referred to as air bubble operation).

In a bathtub device with an air bubble operation function, a circulation adapter with an air bubble generating function is installed on the side wall of the bathtub to spray bathtub water mixed with air bubbles into the bathtub. The circulation adapter is connected to the reheating circulation path. This makes it possible to pour hot water into the bathtub and reheat the bathtub water through the circulation adapter. In addition, by forming a reheating circulation path by operating the reheating circulation pump 400, it is also possible to output a water jet containing air bubbles into the bathtub.

Although not shown in the figure, the circulation adapter has a reheating hot water outlet channel for introducing heated bath water into the bathtub, a bubbled hot water outlet channel for introducing bath water mixed with air bubbles into the bathtub, and a flow path switching mechanism. The flow path switching mechanism is configured to be able to switch between a state in which the reheating hot water outlet channel is open while the bubbled hot water outlet channel is closed to eject normal hot water, and a state in which the reheating hot water outlet channel is closed while the bubbled hot water outlet channel is opened to eject bubbly hot water.

During bubble operation, the jetted water flow containing bubbles creates a warming effect on the bather's body. However, when HD control is started during bubble operation, there are cases where heating of the bath water is not anticipated, and the control valve 330 is open, forming a heat medium circulation path 510 by operating the heating circulation pump 310 and the combustion burner 30b. In this case, even though heating of the bath water is not anticipated, the bubble operation and the reheating operation are essentially performed simultaneously, and there is a risk of an unintended high-temperature jetted water flow being output.

Therefore, in the heating heat source device 100 according to this embodiment, when the bubble operation is performed, the control valve 330 is closed and the opening of the control valve 330 is prohibited according to the control process shown in FIG. 7.

Figure 7 is a flowchart illustrating a modified example of the opening and closing control of the control valve 330 in the heating heat source device 100 according to this embodiment. The control process according to the flowchart shown in Figure 7 is repeatedly executed by the controller 300 shown in Figure 1.

Referring to FIG. 7, in step S11, the controller 300 determines whether or not the bubble operation is being performed. The determination in step S11 can be made based on a user's switch operation on a remote controller (not shown).

During the operation of the bubble treatment (YES in S11), the controller 300 advances the process to step S12 and closes the control valve 330. As described above, by closing the control valve 330, the return path of the heat medium that has passed through the primary heat exchanger 11b through the piping 360, the bath heat exchanger 410 (primary side path 411), the junction 385, the piping 380, the secondary heat exchanger 21b, and the piping 390 to the heating expansion tank 320 is not formed in the heat medium circulation path 510. Therefore, even if the heat medium circulation path 510 is formed by the operation of the heating circulation pump 310 and the combustion burner 30b during the bubble operation, the bath water flowing through the reheating circulation path 520 can be prevented from being heated by liquid-liquid heat exchange between the primary side path 411 and the secondary side path 412 of the bath heat exchanger 410.

Returning to step S01, when the bubble operation is not being performed (NO in S11), the controller 300 allows the control valve 330 to be opened in step S13. In other words, the controller 300 allows the formation of the return path in the heat medium circulation path 510.

In step S14, the controller 300 determines whether or not the reheating operation is in progress. As described above, the determination in step S14 can be made based on the user's switch operation on the remote controller (not shown).

When reheating operation is in progress (YES in S14), the controller 300 opens the control valve 330 in step S15. On the other hand, when reheating operation is not in progress (NO in S15), the controller 300 advances the process to step S16 and determines whether HD control is being applied. HD control is performed at a predetermined time after the start of heating operation. The determination in step S16 can be made based on whether the elapsed time from the start of heating operation has exceeded the predetermined time.

When HD control is being applied (YES in S16), the controller 300 opens the control valve 330 in step S15. On the other hand, when HD control is not being applied (NO in S16), the controller 300 closes the control valve 330 in step S17.

The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is indicated by the claims rather than the above description, and it is intended to include all modifications within the meaning and scope of the claims.

100 Heating heat source device, 300 Controller, 310 Heating circulation pump, 330 Control valve, 400 Reheating circulation pump, 410 Bath heat exchanger, 411 Primary side path, 412 Secondary side path, 510 Heat medium circulation path, 520 Reheating circulation path, 610 UV lamp.

Claims (2)

A heating heat source device,
a heat medium circulation path formed when a first circulation pump is operated, for circulating and supplying a liquid heat medium to a heating terminal connected to the heating heat source device;
A heat source for heating the heat medium;
A control valve arranged to be included in the heat medium circulation path;
a heat exchanger having a primary side path through which the heat medium flows when the control valve is opened;
A reheating circulation path formed when the second circulation pump is operated, in which bath water from the bathtub flows through the secondary side path of the heat exchanger and is then returned to the bathtub;
A sterilization lamp that is arranged to be included in the reheating circulation path and irradiates light rays in a wavelength range having a sterilization effect when turned on;
A heating heat source device comprising: a controller that controls the second circulation pump, the control valve, and the sterilization lamp so as to operate the second circulation pump, turn on the sterilization lamp, and close the control valve during a sterilization operation for sterilizing the bath water flowing through the reheating circulation path using the sterilization lamp. A flow path switching means is further provided, which is connected to the reheating circulation path and is configured to form a flow path for introducing the heated bath water into the bathtub during reheating operation, and to form a flow path for introducing the bath water with air bubbles mixed into the bathtub during air bubble operation.
The heating heat source device according to claim 1 , wherein in the bubble operation, the controller controls the second circulation pump and the control valve to operate the second circulation pump and close the control valve.

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