JP2008008587A - Bath hot water supply equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide bath hot water supply equipment capable of preventing hot water for cleaning from being wastefully consumed, while properly cleaning a part where drainage passes, in a circulation passage. <P>SOLUTION: This bath hot water supply equipment comprises a circulation pump 26 for circulating hot water in a bathtub 5 through the circulation passage J through a latent heat recovery-type heat exchanging portion N2, a drain tank 6 for storing the drainage generated in recovering latent heat in the heat exchanging portion N2, a drainage discharge passage 50 for connecting the drain tank 6 to the circulation passage J, a three-way valve 29 capable of switching a circulation passage opening state and a drainage discharging state, and a check valve 51 for preventing back-flow from a circulation passage side and a drain tank side. A hot water supply passage 22 is connected to the circulation passage J at a part between an installation part of the circulation pump 26 and a connection part of the drainage discharge passage 50, and a purge operation for supplying hot water to the circulation passage J through the hot water supply passage 22 is executed in a state of switching the three-way valve 29 to the drainage discharge state after a drainage discharging operation. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention provides a circulation pump that circulates hot water in a bathtub through a circulation path that passes through a latent heat recovery type heat exchange section that is heated by a heating burner, a water supply section, and the circulation path that passes through the heat exchange section. And a drain tank for storing drain generated by the recovery of latent heat in the heat exchanging portion, and the drain tank at a location closer to the hot water circulation direction than the installation location of the circulation pump in the circulation path. A drain drainage path to be connected; a circulation path open state in which communication between the drain drainage path and the circulation path is blocked and the circulation path is in communication; the drain drainage path and the circulation path are communicated; A three-way valve that can be switched to a drain drainage state that blocks communication between the upper part of the hot water circulation direction and the lower part of the hot water circulation direction with respect to the connection point of the drain drainage channel in the circulation path; Hot water operation for supplying hot water to the bathtub through the hot water passage and the circulation passage by controlling the operation of the burner, the circulation pump, and the three-way valve, and the hot water in the bathtub is circulated through the circulation passage. The present invention relates to a bath hot-water supply facility provided with an operation control means for performing a memorial operation and a drain discharge operation for discharging the drain stored in the drain tank through the drain drain passage and the circulation passage.

  The above bath water supply equipment is used as a latent heat recovery type heat exchanger when performing a hot water operation for supplying hot water to the bathtub through the hot water passage and the circulation path or a memorial operation for circulating hot water in the bathtub through the circulation path. Thus, the drain water generated when the latent heat is recovered is stored in the drain tank. And it becomes the structure which performs the drain discharge operation | movement which discharges the drain water stored in the drain tank using the circulation path provided in order to circulate the hot water in a bathtub, and a circulation pump.

  That is, in the drain discharge operation, by switching the three-way valve to the drain drainage state and operating the circulation pump, the drain water stored in the drain tank is separated from the drain drainage path and the drain drainage path in the circulation path. The lower part of the hot water circulation direction is passed through the connected part and discharged outside.

  In such a hot water supply facility, conventionally, after the process of draining drain water is completed, a purge operation for supplying hot water to the circulation path through the hot water filling path is performed. As an operation, there was one in which hot water was supplied through the hot water filling passage in a state where the three-way valve was switched to the open circuit state (see, for example, Patent Document 1).

  In other words, when performing the purge operation, hot water supplied through the hot water filling passage is caused to flow through the circulation passage and discharged to the outside. At that time, since the three-way valve is switched to the open state of the circulation path, the hot water supplied through the hot water path is connected to the lower side of the hot water circulation direction in the circulation path from the connection point of the hot water path and the upper side of the hot water circulation direction. It will flow through the passages on both sides of the side part.

JP 2005-337544 A

As described above, since the drain water passes through the lower part of the circulating water path in the hot water circulation direction than the connection point with the drain drainage channel in the circulation path, the hot water is passed through the passage corresponding to the lower part of the circulating water path in the hot water circulation direction. By doing so, it is possible to wash the drain water passage location.
However, in the above-described conventional configuration, when performing the purge operation, the hot water supplied through the hot water filling path is connected to the lower side portion in the hot water circulation direction and the upper side portion in the hot water circulation direction from the connection point of the hot water filling path. Therefore, drain water is supplied to one of the passage corresponding to the drain water passage location, that is, the lower portion of the hot water circulation direction and the upper portion of the hot water circulation direction. If a sufficient amount of hot water is passed through to wash the passage location, the same amount of hot water flows through the other passage, which disadvantageously results in wasteful consumption of hot water.

  An object of the present invention is to provide a bath hot water supply facility capable of washing a portion where drain water passes in a circulation path while avoiding wasteful consumption of hot water for washing. The point is to provide.

The hot water supply facility according to the present invention is a circulation pump that circulates hot water in a bathtub through a circulation path that passes through a latent heat recovery type heat exchange section heated by a heating burner,
A hot water path connecting the water supply unit and the circulation path via the heat exchange unit;
A drain tank for storing drain generated by latent heat recovery in the heat exchange unit;
A drain drainage channel connecting the drain tank to a location on the upper side of the circulating water direction than the connection location of the circulation pump in the circulation channel;
An open circuit state in which the communication between the drain drainage channel and the circulation channel is blocked and the circulation channel is in a communication state, the drain drainage channel and the circulation channel are communicated, and the drain drainage channel in the circulation channel A three-way valve that is switchable to a drain drainage state that cuts off the communication between the upper part of the hot water circulation direction and the lower part of the hot water circulation direction than the connection point of
Hot water operation for supplying hot water to the bathtub through the hot water passage and the circulation path by controlling the operation of the heating burner, the circulation pump and the three-way valve, and hot water in the bathtub through the circulation path. And an operation control means for performing a circulation operation and a drain discharge operation for discharging the drain stored in the drain tank through the drain drain passage and the circulation passage, respectively. One feature configuration is
A check valve for preventing a back flow from the circulation path side to the drain tank side is provided in the drain drainage path,
The hot water filling passage is connected to the portion corresponding to the location between the installation location of the circulation pump in the circulation passage and the connection location of the drain drainage passage,
The operation control means is configured to execute a purge operation for supplying hot water to the circulation passage through the hot water filling passage in a state where the three-way valve is switched to a drain drainage state after the drain discharge operation. In the point.

  According to the first characteristic configuration, the operation control means performs the purge operation after the drain discharge operation. That is, hot water is supplied to the circulation path through the hot water filling path with the three-way valve switched to the drainage state. At that time, since the three-way valve is switched to the drain drainage state, the drain drainage channel to which the drain tank is connected and the circulation channel are in communication, and the hot water circulation is performed more than the connection point of the drain drainage channel in the circulation channel. Since the communication between the upper side portion in the direction and the lower side portion in the hot water circulation direction is cut off, the drain drainage channel is connected to the lower side portion in the hot water circulation direction and is cut off from the upper side portion in the hot water circulation direction. . Further, since the hot water filling passage is connected to a portion corresponding to the location between the installation location of the circulation pump in the circulation passage and the connection portion of the drain drainage passage, the hot water supplied through the hot water filling passage is in the circulation passage. It flows through the lower side portion in the hot water circulation direction from the connection point with the hot water passage, and is discharged to the outside through, for example, a bathtub.

  At that time, the communication between the upper part of the hot water circulation direction and the lower part of the hot water circulation direction is blocked by the three-way valve from the connection point of the drain drainage channel. It does not flow through the upper part of the hot water circulation direction than the connection point. Although the drain drainage channel and the circulation channel are in communication, the drain drainage channel is provided with a check valve that prevents backflow from the circulation channel side to the drain tank side. The supplied hot water does not flow to the drain tank side through the drain drainage channel.

  In the drain discharge operation, the three-way valve is switched to the drain drain state and the circulation pump is operated, so that the drain water stored in the drain tank is more hot than the drain drain passage and the connection portion of the circulation passage with the drain drain passage. In the purge operation, the hot water supplied through the hot water filling path is the lower side part in the hot water circulation direction in the circulation path through which the drain water has passed during drain drainage. It is possible to clean the drain water passage location by passing only through the hot water, so that hot water does not flow to the upper side of the circulation path in the hot water circulation direction, and hot water is not consumed wastefully.

  Therefore, it is possible to provide a bath hot water supply facility that can avoid the wasteful consumption of hot water for cleaning while being able to clean the portion of the circulation path where drain water has passed. It was.

  According to a second characteristic configuration of the present invention, in addition to the first characteristic configuration, the operation control means sets the three-way valve to the open circuit state after the drain discharge operation and before performing the purge operation. In the switched state, the hot water existing in the upper part of the circulating water passage in the hot water circulation direction from the connection part of the drain drainage channel in the circulation path flows to the lower part of the hot water circulation direction in the circulation path from the connection part of the drain drainage channel. In order to make this happen, a pre-purge operation for operating the circulation pump is performed.

  According to the second characteristic configuration, the operation control means performs the first purge operation after the drain discharge operation and before executing the purge operation. That is, the circulation pump is operated in a state where the three-way valve is switched to the open state of the circulation path, and the hot water existing in the upper part of the circulation direction of the hot water with respect to the connection point of the drain drainage path in the circulation path is drained in the circulation path. It is made to flow in the lower part of the hot water circulation direction than the connection part of the road.

  If it adds, even if it is a case where the hot water in a bathtub is discharged after hot water filling, a part of hot water will remain in the hot water circulation direction upper side part rather than the connection location of a drain drainage channel. Therefore, by operating the circulation pump in a state where the three-way valve is switched to the circulation path open state before executing the purge operation, such residual water is caused to flow to the lower side portion in the hot water circulation direction and circulate. It becomes possible to wash between the connection point of the drain drainage channel in the channel and the connection point of the hot water channel in the circulation channel.

  Therefore, according to the 2nd characteristic composition, it becomes possible to wash between the connection point of the drain drainage channel in the circulation channel, and the connection point of the hot water supply channel in the circulation channel using the remaining water in the circulation channel. .

  In addition to the first feature configuration or the second feature configuration, the third feature configuration of the present invention is the content of the passage portion from the connection point of the hot water filling passage in the circulation passage to the bath on the lower side in the hot water flow direction. The time obtained by dividing the product by the flow rate per unit time of hot water flowing through the circulation path in the purge operation, or the time obtained by adding the set time for allowance to that time is set as the set time for purge, The operation control means is configured to execute the purge operation until the purge set time elapses.

  According to the third characteristic configuration, the operation control means executes the purge operation until the purge set time elapses. This purge setting time is the unit time of hot water flowing through the circulation path in the purge operation, the internal volume of the passage part from the hot water supply point from the hot water supply path in the circulation path to the bathtub on the lower side of the hot water flow direction The time divided by the hit flow rate, or the time obtained by adding the set time for margin to that time. That is, it is a time during which hot water can surely pass through the entire area of the passage portion from the hot water supply point from the hot water supply path in the circulation path to the bathtub on the lower side of the hot water flow direction, and the shortest of them. It is time corresponding to time. In other words, in the time required to pass the minimum amount of hot water required to wash the passage part from the hot water supply point in the circulation path to the bathtub on the lower side of the hot water flow direction. It is trying to suppress.

  Therefore, the amount of hot water used for cleaning can be suppressed to the minimum required amount, and it is possible to accurately avoid wasteful consumption of hot water for cleaning.

  According to a fourth feature configuration of the present invention, in addition to any one of the first feature configuration to the third feature configuration, the operation control means is configured to stop the heating of the heating burner in the purge operation. There is in point.

  According to the fourth characteristic configuration, in the purge operation, hot water flowing through the hot water filling passage through the heat exchanging section is discharged to the outside, but heating of the heating burner is stopped in the purge operation. Therefore, the hot water discharged to the outside for cleaning is not heated unnecessarily.

  Therefore, according to the fourth feature configuration, the fuel for the burner is not consumed unnecessarily, and the wasteful consumption of fuel can be avoided.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a bath water heater according to the present invention. This bath hot-water supply system heats water from a water supply channel 1 connected to a general household water pipe by a gas combustion burner g1, and supplies hot water after heating with a hot water tap 2 at the tip. The hot water supply heating part A supplied to the hot water and the hot water in the bathtub 5 are heated by the gas combustion type burner g2, and the hot water supply operation part B is added. Each of the heating unit A for hot water supply and the operation unit B for chasing is configured to include a main heat exchanger N1 and a latent heat recovery type heat exchanger N2 arranged in two upper and lower stages, and latent heat recovery type heat exchange is performed. The combustion exhaust gas after heat exchange in the vessel N2 is configured to be discharged to the outside through the exhaust passage 7.

  From the latent heat recovery type heat exchanger N2, drain water which is acidic condensed water is generated by latent heat recovery. This drain water is collected by the drain pan 8 and temporarily stored in the neutralizer 9. ing. Although not described in detail, the neutralizer 9 is loaded with a neutralizing agent (for example, calcium carbonate) that neutralizes the drain water, and the drain water after neutralization is supplied to the drain tank 6. It becomes the structure which stores in.

  A gas supply path G for supplying general household fuel gas is connected to each of the burners g1 and g2 to the hot water supply heating unit A and the memory operation unit B, and an electromagnetic gas for adjusting the fuel gas supply amount. A proportional valve 10 and an intermittent valve 11 for intermittently supplying fuel gas are provided. A combustion fan 12 for supplying combustion air to the burners g1 and g2 is also provided, and an ignition igniter for performing an ignition operation on the burner g1 and a flame rod for detecting whether or not the burner g1 is ignited are provided near the burner g1. Etc. are provided.

  The hot water supply heating section A is connected to a water supply path 1 and a hot water supply path 3 for discharging hot water after heating after passing through the main heat exchanger N1 and the latent heat recovery type heat exchanger N2. The supplied water is heat-exchanged, and hot water having a desired temperature is supplied through the hot water supply passage 3.

  The water supply channel 1 is provided with a water supply thermistor 13 for detecting the water supply temperature and a water amount sensor 14 for detecting the water supply amount, and the water supply channel 1 and the hot water supply channel downstream of the water supply thermistor 13 and the water amount sensor 14. 3 is connected via a water supply bypass 15 so as to bypass the heat exchangers N1 and N2. Furthermore, in the hot water supply path 3, a hot water thermistor 16 that detects the temperature of hot water from the hot water supply heating part A, and a mixture of the amount of hot water from the heat exchanger and the amount of water from the water supply bypass path 15 are sequentially provided from the upstream side. A mixing valve 17 for adjusting the ratio, a hot water thermistor 18 for detecting the temperature of hot water after mixing by the mixing valve 17, a water proportional valve 19 for adjusting the amount of hot water, and an interruption of general hot water supply are detected. An interrupt water amount sensor 20 is provided. A hot water filling passage 22 for supplying hot water from the hot water supply passage 3 to the bathtub 5 from the hot water supply passage 3 between the water proportional valve 19 and the interrupt water amount sensor 20 is branched and connected.

  The remedy operation section B is connected to a bathtub return path 23 and a bathtub outbound path 24 from the bathtub 5, and the bathtub return path 23 and the bathtub outbound path 24 circulate hot water in the bathtub. It is constituted as a circulation path J. And the return path 23 for bathtubs and the outward path 24 for bathtubs are connected to the bathtub 5 through the bath adapter 25, and the circulation pump 26 provided in the return path 23 for bathtubs is driven, The inside of the bathtub 5 While the hot water is circulated through the bathtub return path 23 and the bathtub return path 24, it is configured to perform the memorial heating by the memorial operation section B.

  In the bathtub return path 23, a water level sensor 27 serving as a water level detecting means for detecting the water level in the bathtub 5 by detecting pressure in order from the upstream side, and a bath temperature for detecting the temperature of hot water in the bathtub 5. A three-way valve 29 for switching the connection state between a return thermistor 28 as detection means and a drain drainage channel 50 as will be described later, a circulating pump 26 for circulating hot water, and a water flow switch 30 are provided. A forward thermistor 31 for a bathtub is provided in the outbound path 24.

  Accordingly, the burner g2 in the chasing operation section B constitutes a heating burner, and the latent heat recovery heat exchanger N2 in the chasing operation section B constitutes a latent heat recovery heat exchange section.

  The three-way valve 29 is configured to block the communication between the drain drainage channel 50 and the circulation channel J and to open the circulation channel (see FIGS. 3 and 4), and to connect the drain drainage channel 50 and the circulation channel. It is possible to switch to a drain drainage state (see FIG. 5) that communicates with J and blocks communication between the upper part of the hot water circulation direction and the lower part of the hot water circulation direction from the connection point of the drain drainage channel 50 in the circulation path J. It is configured.

  The bath hot water filling path 22 is provided with a hot water solenoid valve 32 and a hot water check valve 33 for opening and closing the hot water filling path 22 from the upstream side. The hot water filling path 22 also functions as a supply path for supplying water from the water supply source into the bathtub 5. An air layer forming hopper 34 is interposed between the hot water solenoid valve 32 and the hot water check valve 33.

  A drain drainage channel 50 is provided for connecting the drain tank 6 to a location closer to the hot water circulation direction than the location where the circulation pump 26 is installed in the return channel 23 for the bathtub that constitutes the circulation channel J. Is provided with a check valve 51 for preventing a reverse flow from the bathtub return path 23 side to the drain tank 6 side. Accordingly, the hot water filling path 22 is connected to a portion corresponding to a portion between the installation location of the circulation pump 26 and the connection location of the drain drainage channel 50 in the return path 23 for the bathtub constituting the circulation path J.

  An operation control unit H1 as a control means for controlling the operation state is provided with a microcomputer so as to communicate with a remote control device R1 installed indoors. The remote control device R1 includes an operation switch 37 for instructing start and stop of operation, an automatic switch 38 for instructing automatic operation, a temperature setting switch 39 for setting a general hot water supply temperature, and a water level setting switch for setting a target water level in the bathtub 5 40, an additional hot water switch 41 for additionally supplying hot water to the bathtub, a memorial switch 42 for instructing memorial operation, and the like.

The contents of control by the operation control unit H1 will be described.
The operation control unit H1 is in a controllable state when the operation switch 37 of the remote control device R1 is operated, and executes general hot water supply operation control for supplying hot water from the hot water tap 2 when the hot water tap 2 is opened. When the automatic switch 38 of the remote control device R1 is operated, automatic operation, that is, a hot water operation, a memorial operation, and a keep operation, which will be described later, are executed. Further, when the addition water switch 41 is operated, the addition water operation is executed, and when the addition switch 42 is operated, the addition operation is executed.

  Further, the operation control unit H1 is configured to execute a drain discharge operation for discharging the drain stored in the drain tank 6 through the drain drainage passage 50 and the circulation passage J when it is time to drain the drain water. After the discharge operation, with the three-way valve 29 switched to the open circuit state, the hot water present in the upper part of the hot water circulation direction from the connection point of the drain water channel 50 in the circuit J is drained in the circuit J. 50, a pre-purge operation is performed to operate the circulation pump 26 to flow to the lower side of the hot water circulation direction from the connection point 50, and after the pre-purge operation, the three-way valve 29 is switched to the drainage state. A purge operation for supplying hot water to the circulation path J through the tension path 22 is executed.

  When the general hot water supply operation is described, the operation control unit H1 opens the hot water tap 2 and when the amount of water detected by the water amount sensor 14 becomes equal to or greater than the set water amount for starting combustion, the combustion fan 12 in the hot water supply heating unit A Then, the intermittent valve 11 is opened, the opening of the gas proportional valve 10 is adjusted and the burner g1 is ignited by the igniter, the set temperature by the temperature setting switch 39, the detected water temperature by the water supply thermistor 13, and the amount of water Based on the amount of water detected by the sensor 14, the opening of the gas proportional valve 10 is adjusted, and the opening of the mixing valve 17 is also adjusted to control the fuel supply amount so that the hot water supply temperature becomes the set temperature. When water flow is no longer detected, the gas proportional valve 10 and the intermittent valve 11 are closed to stop the combustion of the burner g1, and the combustion fan 12 is also stopped to end the general hot water supply operation.

  Next, automatic operation will be described. In this automatic operation, first, a hot water bathing operation is performed. In other words, when the hot water solenoid valve 32 is opened and the supply of hot water to the bathtub 5 is started, the burner g1 is ignited and the fuel supply amount is adjusted while adjusting the fuel supply amount in the same manner as the general hot water supply operation described above. Supply hot water. At that time, as shown in FIG. 3, hot water filling is performed in a state where the hot water flows through the bathtub return path 23 and the bathtub return path 24, respectively. When the detected water level of the water level sensor 27 is equal to or higher than the set water level, the combustion of the burner g1 is stopped, and the hot water solenoid valve 32 is closed to end the hot water filling.

  When the hot water filling is finished, the memorial operation is executed. That is, as shown in FIG. 4, the circulation pump 26 for chasing is driven, and hot water in the bathtub 5 is circulated through the bathtub return path 23, the chasing heating section B, and the bathtub outbound path 24. The fuel supply amount to the burner g2 is controlled so that the temperature detected by the return thermistor 28 becomes the temperature set by the temperature setting switch 42. When the temperature detected by the return thermistor 28 reaches the temperature set by the temperature setting switch 42 of the remote control device R, the gas proportional valve 10 and the intermittent valve 11 are closed, and the combustion of the burner g2 is stopped. The combustion fan 12 is stopped to end the chasing operation.

  Subsequently, the keep operation is executed for a set time. In the keep operation, the water level in the bathtub 5 is detected by the water level sensor 27 so that the hot water temperature and the water level in the bathtub 5 are set, and the bathtub 5 is set so that the detected water level becomes the set water level. The hot water in the bathtub 5 is circulated through the bathtub return path 23, the bathtub return path 24, etc., and the temperature detected by the return thermistor 28 is set. Similarly to the hot water supply operation, the combustion state of the burner g2 in the reheating heating section B is controlled so as to reach the temperature.

  In the addition hot water operation, the hot water filling operation is performed on the bathtub 5 so that the water level of the bathtub 5 becomes the set water level, and the hot water supply is stopped when the set water level is reached. In the chasing operation performed by operating the chasing switch 42, the same control as the chasing operation in the automatic operation is executed.

Next, specific operations in the operation control unit H1 for the drain discharge operation, the first purge operation, and the purge operation will be described with reference to flowcharts.
As shown in FIG. 2, the operation control unit H1 determines whether or not it is a discharge timing at which drain water should be discharged (step 1). The discharge timing is a timing at which hot water is not present in the bathtub 5 and it is assumed that the drain water stored in the drain tank 6 needs to be discharged. For example, after hot water filling operation, it is determined by the detection value of the water level sensor 27 that the discharge of hot water in the bathtub 5 has ended.

  If it is the discharge timing at which drain water should be discharged, the three-way valve 29 is switched to the drain drain state (step 2). That is, the drain drainage channel 50 and the circulation channel J communicate with each other, and the communication between the upper part of the hot water circulation direction and the lower part of the hot water circulation direction is cut off from the connection point of the drain drainage channel 50 in the circulation path J. . More specifically, the drain drainage state means that the three-way valve 29 connects the drain drainage channel 50 and the lower side portion in the hot water circulation direction with respect to the three-way valve 29 in the circulation channel J, and in the circulation channel J. This is a state in which communication between the lower side portion in the hot water circulation direction and the upper side portion in the hot water circulation direction is cut off from the three-way valve 29.

  Next, the operation of the circulation pump 26 is started (step 3). That is, as shown in FIG. 5, the drain water stored in the drain tank 6 passes through the drain drainage passage 50, the three-way valve 29, and the lower side portion in the hot water circulation direction with respect to the three-way valve 29 in the circulation passage J. It is made to flow to the outside through the bathtub 5 and discharged from the outlet. When the set time for drainage elapses after starting the operation of the circulation pump 26, the operation of the circulation pump 26 is stopped (steps 4 and 5). The set time for drainage varies depending on the capacity of the drain tank 6 and the capacity of the circulation pump 26, but is generally a time of several seconds to several tens of seconds, for example. Steps 2 to 5 correspond to the drain discharge operation.

  When the drain discharge operation ends, the three-way valve 29 is switched to the circulation path open state, and the operation of the circulation pump 26 is started (steps 6 and 7). That is, as shown in FIG. 6, the hot water existing in the upper part of the circulation path J in the hot water circulation direction than the connection part of the drain drainage path 50 is lower than the connection part of the drain drainage path 50 in the circulation path J. It is made to flow to a side part and is discharged outside through the bathtub 5. When the pre-purge set time elapses after the operation of the circulation pump 26 is started, the operation of the circulation pump 26 is stopped (steps 8 and 9). The set time for the first purge differs depending on the difference in the capacity of the drain tank 6 and the capacity of the circulation pump 26 in the same manner as the set time for drainage, but is generally, for example, about several seconds to several tens of seconds. Steps 6 to 9 correspond to the first purge operation. By performing this first purge operation, it is possible to clean between the connection point of the drain drainage channel 50 in the circulation path J and the connection point of the hot water filling path 22 in the circulation path J.

  When the first purge operation is completed, the purge operation is executed. That is, the three-way valve 29 is switched to the drainage state, the hot water solenoid valve 32 is opened, and hot water is supplied from the hot water passage 22 (steps 10 and 11). In this purge operation, even when the amount of water detected by the water amount sensor 14 becomes equal to or greater than the set water amount for starting combustion, the heating by the burner g2 is stopped and the hot water heating operation is not executed.

  As shown in FIG. 7, the hot water supplied from the hot water filling path 22 flows in the lower part of the circulation path J from the connecting portion with the hot water filling path 22 and flows to the outside through the bathtub 5. Will be discharged. Although the circulation path J and the drain drainage path 50 are in communication, the presence of the check valve 51 prevents hot water from flowing to the drain tank 6 side, and the hot water flows in the circulation path J. It is also possible to prevent the upper portion of the hot water circulation direction from flowing more than the connecting portion with the stretch path 22.

  When the purge set time elapses after the hot water supply is started, the hot water supply is stopped, the three-way valve 29 is switched to the circulation path open state, and the purge operation is terminated (steps 12, 13, and 14). The purge set time is the internal volume of the passage portion from the connection point of the hot water passage 22 in the circulation path J to the bathtub 5 on the lower side of the hot water flow direction, and the hot water flowing through the circulation path J in the purge operation. The time obtained by adding the set time for margin to the time divided by the flow rate per unit time is set as the set time for purge.

  In other words, the purge setting time T is calculated by the following equation (1).

  The “purge pipe volume” in Equation 1 is the internal volume of the passage part from the connection point of the hot water passage in the circulation path J to the bathtub on the lower side of the hot water flow direction. It is the total length of the passage part from the connection place of the hot water path in the circulation path J to the bathtub on the lower side in the hot water flow direction. The “purge pipe diameter” is the inner diameter of the pipe in the circulation path J. Further, the “purge water amount” is a flow rate per unit time of hot water flowing through the hot water passage, and is a water amount detected by a water amount sensor. By the way, the pipe diameter is generally about 10 mm, and the total extension of the pipe varies depending on the situation when the hot water supply equipment is installed, but a fixed value set in advance for each model should be set. Alternatively, it may be set by switching to a plurality of stages so that a value close to the actual installation state can be selected by a changeover switch or the like. “Α” in Equation 1 is a setting time for margin.

  By performing the first purge operation and the purge operation as described above, the portion where the drain water passes in the circulation path J can be washed with tap water.

[Another embodiment]
Hereinafter, other embodiments are listed.

(1) In the above embodiment, the operation control unit is configured to execute the first purge operation after the drain discharge operation and before the purge operation. It is good also as a structure which does not perform. In this case, it is preferable to provide the connection place of the hot water filling path and the connection place of the drain drainage path in the circulation path as close as possible.

(2) In the above embodiment, the operation control means is configured to stop the heating of the heating burner in the purge operation. However, the heating burner is also heated during the purge operation. It is good also as a structure.

(3) In the above embodiment, the purge set time circulates in the purge operation the internal volume of the passage portion from the connection point of the hot water passage 22 in the circulation path J to the bathtub 5 on the lower side in the hot water flow direction. The time obtained by adding the setting time for allowance to the time divided by the flow rate per unit time of the hot water flowing through the path J is set as the setting time for purging, but without adding the setting time for allowance, A time obtained by dividing the internal volume by the flow rate per unit time of hot water may be set as the purge set time.

(4) In the above embodiment, the time when drain water should be discharged is exemplified when the discharge of hot water in the bathtub after completion of the hot water operation is completed. It is good also as a structure which equips with the switch which commands drain drainage, and commands suitably when an operator does not have water in a bathtub. At that time, if the drain amount in the drain tank is equal to or larger than the set amount, it is preferable to notify that fact.

(5) In the above embodiment, the latent heat recovery type heat exchange section includes a heat exchanger heated by a gas combustion type burner, and hot water heated by the heat exchanger passes through the circulation path to the bathtub. However, instead of such a configuration, for example, hot water heated by a gas combustion type burner and hot water hot-exchanged via a liquid heat exchanger are passed through the circulation path to the bathtub. It is good also as a structure to circulate, and the structure for heating the hot and cold water to circulate can be changed suitably, and can be implemented. Similarly, the hot water supplied through the hot water supply passage may be configured to supply hot water heated by a gas combustion type burner and hot water hot-exchanged via a liquid-liquid heat exchanger to the bathtub.

Schematic diagram of hot water supply equipment Flow chart of control operation The figure which shows the passage state in the hot water operation The figure which shows the flow state in memorial operation Diagram showing the flow state in drain drainage operation Diagram showing the flow state in the first purge operation Diagram showing the flow state in purge operation

Explanation of symbols

6 Drain tank 22 Hot water filling path 26 Circulation pump 29 Three-way valve 50 Drain drainage path 51 Check valve g2 Heating burner J Circulation path H1 Operation control means N2 Heat exchanger

Claims (4)

A circulation pump that circulates hot water in the bathtub through a circulation path that passes through a heat exchange section of a latent heat recovery type that is heated by a heating burner;
A hot water path connecting the water supply unit and the circulation path via the heat exchange unit;
A drain tank for storing drain generated by latent heat recovery in the heat exchange unit;
A drain drainage channel connecting the drain tank to a location closer to the hot water circulation direction than an installation location of the circulation pump in the circulation channel;
An open circuit state in which the communication between the drain drainage channel and the circulation channel is blocked and the circulation channel is in a communication state, the drain drainage channel and the circulation channel are communicated, and the drain drainage channel in the circulation channel A three-way valve that is switchable to a drain drainage state that cuts off the communication between the upper part of the hot water circulation direction and the lower part of the hot water circulation direction than the connection point of
Hot water filling operation for controlling the operation of the heating burner, the circulation pump, and the three-way valve to supply hot water to the bathtub through the hot water passage and the circulation passage, hot water in the bathtub through the circulation passage A bath hot-water supply facility provided with an operation control means for performing a recuperation operation for circulating the water and a drain discharge operation for discharging the drain stored in the drain tank through the drain drain passage and the circulation passage. ,
A check valve for preventing a back flow from the circulation path side to the drain tank side is provided in the drain drainage path,
The hot water filling passage is connected to the portion corresponding to the location between the installation location of the circulation pump in the circulation passage and the connection location of the drain drainage passage,
The operation control means is configured to execute a purge operation for supplying hot water to the circulation passage through the hot water filling passage in a state where the three-way valve is switched to a drain drainage state after the drain discharge operation. Bath water heater.   After the drain discharge operation and before the purge operation, the operation control means switches the three-way valve to the circulation path open state, and connects the drain drainage path in the circulation path. In order to cause the hot water existing in the upper part of the hot water circulation direction to flow to the lower part of the hot water circulation direction rather than the connection point of the drain drainage channel in the circulation path, the first purge operation for operating the circulation pump is performed. Constructed bath water heater. The internal volume of the passage portion from the connection point of the hot water passage in the circulation path to the bathtub on the lower side in the hot water flow direction is set to a flow rate per unit time of hot water flowing through the circulation path in the purge operation. Or the time set by adding the extra set time to that time is set as the purge set time,
The bath hot water supply equipment according to claim 1 or 2, wherein the operation control means is configured to execute the purge operation until the purge set time elapses.   The bath hot water supply equipment according to any one of claims 1 to 3, wherein the operation control means is configured to stop heating of the heating burner in the purge operation.

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