JP6605962B2 - Bath water heater - Google Patents

Description

  The present invention relates to a bath water heater that controls the amount of gas supplied to a hot water supply burner and a bath reheating burner with a common proportional valve.

  In bath water heaters, the provision of gas proportional valves for adjusting the supply of combustion gas separately to the hot water supply burner and the bath reheating burner is not performed due to demands for cost reduction, etc. A common gas proportional valve is provided. When the hot water supply operation and the bath reheating operation are performed at the same time and the hot water supply burner and the bath reheating burner are simultaneously burned, the combustion amount of the hot water supply burner is given priority so that the hot water supply temperature becomes the target temperature. Thus, the opening degree of the gas proportional valve is controlled.

  If the opening of the gas proportional valve during simultaneous combustion is small due to priority on the hot water supply side and the temperature of the bath water returning from the bath is low, the temperature of the heat exchanger for bath reheating does not rise so much and combustion Moisture in the exhaust is cooled by the heat exchanger for bathing, and condensation occurs.

  Therefore, various controls for preventing the above-mentioned condensation have been proposed. For example, in Patent Document 1 described below, when simultaneous combustion is performed, the possibility of condensation is determined based on the temperature of circulating water from a bath-heating heat exchanger, and it is determined that there is a possibility of condensation. A technique for temporarily interrupting combustion of a reheating burner is disclosed.

  Further, Patent Document 2 below discloses a bath reheating heat when the temperature of water entering the heat exchanger for reheating the bath is lower than a predetermined temperature and the opening of the gas proportional valve is equal to or lower than a predetermined temperature at the time of simultaneous combustion. Control is disclosed in which the flow rate is reduced by reducing the speed of a circulation pump that circulates bathtub water through an exchanger. By reducing the flow rate of the bathtub water that flows through the bath-heating heat exchanger, the temperature drop of the bath-heating heat exchanger is reduced to prevent condensation.

JP 2001-33099 A Japanese Utility Model Publication No. 2-124442 Patent No. 4071224

  If the can body (combustion chamber) for storing the burner for heating the hot water supply heat exchanger and the can body for storing the burner for heating the heat exchanger for bathing are completely separated, the cost increases. Therefore, these burners are divided into left and right inside a common can body, and a hot water supply heat exchanger and a bath reheating heat exchanger are arranged above each, and a hot water supply heat exchanger and a reheating bath are disposed. There is a structure in which the fins of the heat exchanger are connected and the inside of the can below the fins is partitioned by a partition plate to form two combustion chambers (see, for example, Patent Document 3).

  When a combustion chamber with such a structure is used, the heat generated by the combustion of the hot water burner is transferred to some extent to the heat exchanger for reheating the bath. The occurrence of condensation is suppressed to some extent by the heat transfer.

  By the way, many bath water heaters have a bypass path that connects the inlet side and the outlet side of the hot water heat exchanger and a mixing valve that adjusts the amount of water supplied to the bypass path, and are heated through the hot water heat exchanger. It has a function of mixing hot water and hot water that has bypassed the hot water supply heat exchanger through a bypass path to discharge hot water.

  In the hot water supply operation, this mixing valve is normally controlled to be closed or opened in a small amount. Thereby, the quantity of water which flows into the heat exchanger for hot water supply increases, and it can improve thermal efficiency. For example, when the hot water supply temperature exceeds the set temperature even when the hot water supply burner is burned at the minimum combustion amount, the mixing valve is opened to mix the hot water from the bypass path and lower the hot water supply temperature.

  With normal water supply that controls the mixing valve to be closed or opened in a small amount, the amount of water supplied through the hot water heat exchanger increases, so the temperature of the hot water heat exchanger does not rise so much and the hot water supply side heat exchanger Little heat is transferred to the bath heat exchanger through the fins. Therefore, it is not possible to sufficiently enhance the effect of suppressing the condensation generated in the heat exchanger for bathing at the time of simultaneous combustion by the heat transmitted through the fins, and the combustion of the burner on the side of the bath is stopped to prevent condensation, etc. The frequency of implementing other measures will increase, and it will take a long time to retreat the bath.

  The present invention has been made to solve the above problems, and in a structure where heat is transferred from the hot water supply side to the heat exchanger for reheating the bath, the occurrence of condensation during simultaneous combustion is effectively suppressed. The object is to provide a bath water heater that can be used and suppressed.

  The gist of the present invention for achieving the object lies in the inventions of the following items.

[1] a heat exchanger for hot water supply;
A hot water supply burner for heating the hot water supply heat exchanger;
A heat exchanger for bathing, which is thermally connected to the heat exchanger for hot water supply,
A bath burner for heating the bath-heating heat exchanger;
A proportional valve for adjusting the amount of gas supplied to the hot-water supply burner and the bath burner;
A hot water supply path in which the inlet side is connected to a water supply source, the outlet side is connected to a hot water outlet through the hot water heat exchanger,
A bypass path for connecting the inlet side and the outlet side of the hot water path, bypassing the hot water heat exchanger,
A mixing valve for adjusting the amount of water supplied to the bypass path;
A bath reheating circuit for taking bath water from the bathtub and returning it to the bathtub via the bath reheating heat exchanger;
A circulation pump for circulating bath water in the bath reheating circuit;
A controller for controlling the combustion of the hot water burner and the bath burner and the opening of the mixing valve;
The controller controls the opening of the proportional valve by giving priority to the hot water supply side when performing hot water supply and bath reheating at the same time, and increases the amount of water supplied to the bypass path as compared to the case of using hot water alone. The bath water heater is characterized in that the opening of the mixing valve is adjusted to produce hot water at a hot water supply set temperature.

In the above invention, since the hot water supply heat exchanger and the bath reheating heat exchanger are thermally connected, the heat on the hot water supply side is transferred to the bath reheating side during simultaneous combustion. Therefore, when hot water supply and bath reheating are performed simultaneously, the opening of the mixing valve is adjusted ( increased ) so as to increase the amount of water supplied to the bypass path compared to the case of using hot water alone, thereby creating hot water at the hot water supply set temperature. . That is, in order to make hot water with a hot water supply set temperature by increasing the opening of the mixing valve (mixing a lot of water supply), it is necessary to make hot water with a hot water heat exchanger, so the mixing valve is closed Compared with, the hot water heat exchanger becomes hot. As a result, the amount of heat transferred from the hot water supply heat exchanger to the bath reheating heat exchanger increases, and condensation in the bath reheating heat exchanger during simultaneous combustion is prevented. In addition, when using hot water alone, the mixing valve is closed or opened in a small amount. Thereby, a large amount of feed water flows through the hot water supply heat exchanger, the hot water supply heat exchanger does not reach a high temperature, and thermal efficiency can be improved. Examples of thermal connection, for example, when the heat exchanger for hot water supply and the fins of the heat exchanger for bathing are connected, or when the heat is transferred via the partition plate or the can itself and so on.

[2] If the controller controls the opening of the mixing valve in the same way as when using hot water alone when performing hot water supply and bath reheating at the same time, whether or not condensation occurs in the bath reheating heat exchanger [1] characterized in that, when it is determined that dew condensation has occurred, the opening of the mixing valve is adjusted so that the amount of water supplied to the bypass path is increased compared to the case of using hot water alone. The listed bath water heater.

  In the above invention, if condensation does not occur with the mixing valve closed, hot water supply and bath reheating are simultaneously used with the mixing valve closed. Thereby, the thermal efficiency in the heat exchanger for hot water supply improves.

[3] The hot-water supply burner is composed of a plurality of sub-burners,
When performing the hot water supply and the bath reheating at the same time, the control unit preferentially burns the sub burner closest to the bath reheating heat exchanger [1] or [ 2].

  In the above-described invention, the sub-burner closest to the bath-heating heat exchanger is preferentially burned, so that the heat on the hot-water supply heat exchanger side is easily transmitted to the bath-heating heat exchanger.

[4] When the hot water supply and bath reheating are performed simultaneously, the control unit adjusts the opening of the mixing valve so as to increase the amount of water supplied to the bypass path as compared with the case of using hot water alone. Even if hot water is produced, it is determined whether or not condensation occurs in the bath-heating heat exchanger. If it is determined that condensation occurs, the supply of gas to the hot water burner is shut off [1. ] The bath water heater as described in any one of [3].

  In the above invention, even when the opening of the mixing valve is set to a large value, if there is a possibility that condensation occurs in the heat exchanger for reheating the bath due to simultaneous combustion, the gas to the hot water burner is prevented in order to prevent condensation. Cut off the supply and control to single combustion on the hot water supply side.

[5] It further has a temperature sensor for detecting the temperature of water entering the heat exchanger for bathing the bath,
The control unit performs the determination by adding the amount of heat transmitted from the hot water supply heat exchanger side to the bath reheating heat exchanger to the detected temperature of the temperature sensor and the combustion amount of the bath burner. The bath water heater according to [2] or [4].

  In the above invention, whether or not condensation occurs in the heat exchanger for bath reheating, taking into account the amount of heat transmitted from the hot water supply heat exchanger side to the bath reheating heat exchanger in addition to the bath return temperature and the amount of combustion in the bath burner. Determine.

[6] The bath hot water supply according to any one of [1] to [5], wherein the bath-heating heat exchanger is a latent heat recovery type heat exchanger that recovers latent heat and sensible heat. vessel.

  According to the bath water heater according to the present invention, in the structure in which heat is transferred from the hot water supply side to the heat exchanger for bathing, it is possible to suppress the occurrence of condensation during simultaneous combustion by effectively using the heat transfer. .

It is a figure which shows schematic structure of the bath water heater which concerns on embodiment of this invention. It is a figure which shows the schematic structure of a disassembled perspective view and combustion chamber of the bath water heater which concerns on embodiment of this invention. It is a figure which shows the relationship between the combustion amount (number) of a hot water supply side, and the opening degree of a gas proportional valve. It is a figure which shows the determination based on correlation data. It is a flowchart which shows the process regarding control of the bypass mixing valve which the bath water heater which concerns on embodiment of this invention performs. It is a flowchart which shows the process regarding control of the bypass mixing valve and simultaneous combustion which the bath water heater which concerns on embodiment of this invention performs.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram showing a schematic configuration of a bath water heater 10 according to an embodiment of the present invention. The bath water heater 10 is a hot water supply function for heating hot water to supply water to a predetermined tap, a pouring function for pouring (filling) the bathtub 2, and a bath chasing for hot water (tub water) in the bathtub 2. Has a whispering function.

  The bath water heater 10 is provided with a vertically long cylindrical combustion chamber 13 into which air blown by the combustion fan 11 is sent from below and provided with an exhaust port 12 at the top. The combustion chamber 13 is partitioned into two chambers by a vertically-dividing partition plate 14, a hot water supply burner 21 is disposed on one side, and a bath burner 31 is disposed on the other side. The hot water supply burner 21 is composed of three burners A, burner B, and burner C in the order closer to the partition plate 14. The bath burner 31 is composed of one burner.

  Above the hot water supply burner 21, a hot water supply heat exchanger 22 for heating the supplied water with heat from the hot water supply burner 21 is disposed. Above the bath burner 31, a bath heat exchanger 32 for heating the bath water with heat from the bath burner 31 is arranged.

  The hot water supply heat exchanger 22 is arranged downstream of the hot water sensible heat exchanger 22a mainly by the sensible heat exchanger 22a for recovering sensible heat of the exhaust gas, and mainly in the latent heat of the exhaust gas. It is comprised with the latent heat exchanger 22b for hot water supply which collect | recovers.

  Similarly, the bath heat exchanger 32 is disposed downstream of the bath sensible heat exchanger 32a mainly by the sensible heat exchanger 32a for recovering the sensible heat of the exhaust, and mainly in the exhaust flow. It comprises a bath latent heat exchanger 32b that collects the latent heat of the exhaust.

  In the middle of the gas supply pipe 40 connected to the combustion gas supply source, there is provided a source gas electromagnetic valve 41 for switching whether or not the combustion gas from the supply source is shut off, and downstream of the hot water supply burner 21 and A gas proportional valve 42 for arbitrarily adjusting the amount of combustion gas supplied to the bath burner 31 is provided. The gas supply pipe 40 branches into four downstream of the gas proportional valve 42, and each of the branched gas supply pipes 40 reaches the burner A, the burner B, the burner C, and the bath burner 31 of the hot water supply burner 21.

  Each of the gas supply pipes 40 branched into four is provided with gas electromagnetic valves 43 to 46 for shutting off the supply of combustion gas. Specifically, the first hot water gas electromagnetic valve 43 is provided in the middle of the gas supply pipe 40 from the gas proportional valve 42 to the burner A, and the second hot water supply is provided in the middle of the gas supply pipe 40 from the gas proportional valve 42 to the burner B. The gas solenoid valve 44 is in the middle of the gas supply pipe 40 from the gas proportional valve 42 to the burner C, and the third hot water gas solenoid valve 45 is in the middle of the gas supply pipe 40 from the gas proportional valve 42 to the bath burner 31. A bath gas solenoid valve 46 is provided.

  A water supply pipe 50 that receives supply of water from a water supply source is connected to the inlet side of the hot water latent heat exchanger 22b, and the outlet side of the hot water latent heat exchanger 22b is connected to the inlet side of the hot water sensible heat exchanger 22a. A hot water supply pipe 51 leading to the hot water tap is connected to the outlet side of the sensible heat exchanger 22a for hot water supply. A water amount sensor 52 for detecting the amount of water supplied through the water supply pipe 50 is provided in the middle of the water supply pipe 50 leading to the inlet side of the hot water latent heat exchanger 22b. A water amount servo 53 for adjusting (restricting) is provided.

  A bypass pipe 54 branched from the water supply pipe 50 at a predetermined position downstream of the water amount servo 53 is joined and connected to a predetermined position of the hot water supply pipe 51. A bypass mixing valve 55 for adjusting the amount of water supplied to the bypass pipe 54 is provided at a location where the bypass pipe 54 branches from the water supply pipe 50. A hot water supply path is constituted by the hot water supply pipe 50 and the hot water supply pipe 51, and the bypass pipe 54 connects the inlet side and the outlet side of the hot water supply path by bypassing the hot water supply heat exchanger 22.

  At a predetermined location of the hot water supply pipe 51 between the outlet of the hot water sensible heat exchanger 22a and the junction of the bypass pipe 54, heat exchange for detecting the temperature of the hot water coming out of the hot water sensible heat exchanger 22a. A temperature sensor 56 is provided, and a hot water supply temperature sensor 57 for detecting a hot water supply temperature is provided at a predetermined location of the hot water supply pipe 51 downstream from the joining location of the bypass pipe 54.

  A bath return pipe 60 connects the entrance side of the bath latent heat exchanger 32 b of the bath heat exchanger 32 and the bathtub water intake 3 provided in the bathtub 2. The outlet side of the bath latent heat exchanger 32b is connected to the inlet side of the bath sensible heat exchanger 32a, and the outlet side of the bath sensible heat exchanger 32a is the bathtub water discharge port 4 provided in the bathtub 2. Are connected through a bath-out pipe 61. The bath return pipe 60, the bath heat exchanger 32, and the bath going pipe 61 constitute a bath reheating circuit.

  In the middle of the bath return pipe 60, a circulation pump 62 for circulating the bath water in the bath 2 through the bath heat exchanger 32 is provided. Furthermore, the bath return pipe 60 on the downstream side of the circulation pump 62 is provided with a running water switch 63 for detecting whether or not the bath return pipe 60 has a flow of hot water over a certain level.

  The bath return pipe 60 slightly upstream of the circulation pump 62 is provided with a bath return temperature sensor 64 for detecting the temperature of the bath water taken from the bathtub 2. A bath temperature sensor 65 for detecting the temperature of the bath water returning to the bathtub 2 through the bath tube 61 is provided in the middle of the bath tube 61.

  Furthermore, the bath return pipe 60 near the place where the bath return temperature sensor 64 is provided and the hot water supply pipe 51 near the place where the hot water supply temperature sensor 57 is provided are connected by a connecting pipe 66. Are inserted with a pouring electromagnetic valve 67 for switching the connecting pipe 66 between an open state and a shut-off state, and a check valve 68 for preventing a back flow from the bath return pipe 60 side to the hot water supply pipe 51. .

  In the combustion chamber 13, there is provided a drain receiver 15 that is disposed below the hot water latent heat exchanger 22 b and the bath latent heat exchanger 32 b, and receives the drain generated by these, and receives the drain receiver 15. The drain is sent to the neutralizer 17 through the recovery pipe 16, neutralized by the neutralizer 17, and then discharged from the discharge port.

  In addition, the bath water heater 10 includes a control unit that controls the operation of the bath water heater 10. Connected to the control unit is an operating unit that receives various settings and driving instructions from the user, and a remote controller that includes a display unit for displaying setting contents and driving conditions. The control unit is composed of circuits having a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), etc. as main parts, and the CPU executes various processes according to programs stored in the ROM. Thus, the operation as the bath water heater 10 is realized.

  FIG. 2 is a schematic cross-sectional view of the combustion chamber 13 and an exploded perspective view of the bath water heater 10. In the cross section of the combustion chamber 13 shown in FIG. 2, the latent heat exchanger and the sensible heat exchanger are not shown separately in the hot water supply heat exchanger 22 and the bath heat exchanger 32. Each of the hot water supply heat exchanger 22 and the bath heat exchanger 32 includes a heat receiving pipe 24 through which water supply and bath water pass, and a large number of fins (heat receiving plates) 25 attached around the heat receiving pipe 24. Yes. The fins 25 on the hot water supply heat exchanger 22 side and the fins 25 on the bath heat exchanger 32 side are connected in common. The fin 25 is provided with a cut from below at a position between the hot water supply heat exchanger 22 and the bath heat exchanger 32, and the upper end of the partition plate 14 is inserted into this cut and terminates.

  Since the hot water supply heat exchanger 22 and the fins 25 of the bath heat exchanger 32 are connected, when the hot water supply burner 21 is burned, the heat on the hot water supply heat exchanger 22 side is exchanged through the fins 25. It is the structure transmitted to the vessel 32 (heat transfer 1 in FIG. 2). Further, heat is transferred from the hot water supply heat exchanger 22 to the bath heat exchanger 32 through the partition plate 14 partitioning the inside of the can (heat transfer 2 in FIG. 2), or through the outer copper inner cylinder through which the heat receiving pipe 24 passes. Heat is transferred (heat transfer 3 in FIG. 2). In this way, the hot water supply heat exchanger 22 and the bath heat exchanger 32 are thermally connected.

  Next, an outline of the hot water supply operation, the pouring operation, the bath reheating operation, and the operation in simultaneous use of the hot water supply and the bath reheating in the bath water heater 10 will be described.

<Hot-water supply operation (use of hot-water supply alone)>
When the hot water tap is opened and water flows through the water supply pipe 50, the water flow is detected by the water amount sensor 52. When the water amount sensor 52 detects water flow, the control unit ignites the hot water supply burner 21 and causes the hot water supply burner 21 to burn combustion gas. The water supply from the water supply source is heated by receiving the heat of the exhaust from the hot water supply burner 21 when passing through the hot water latent heat exchanger 22b and the hot water sensible heat exchanger 22a, and the bypass mixing valve 55 is open. After being mixed with the water supplied from the bypass pipe 54, the hot water is discharged to a hot water tap. The control unit controls the combustion amount of the hot water burner 21 and the opening degree of the bypass mixing valve 55 so that the hot water temperature detected by the hot water temperature sensor 57 becomes the hot water set temperature. When the water amount sensor 52 no longer detects water flow, the supply of the combustion gas to the hot water supply burner 21 is cut off and the combustion of the hot water supply burner 21 is stopped.

  In the hot water supply single operation, the bypass mixing valve 55 is normally controlled to be closed or opened in a small amount. Thereby, the quantity of water which flows into the heat exchanger 22 for hot water supply increases, and it can improve thermal efficiency. For example, when the hot water supply temperature exceeds the set temperature even when the hot water supply burner 21 is burned at the minimum combustion amount, the bypass mixing valve 55 is opened to mix the hot water from the bypass pipe 54 and lower the hot water supply temperature. .

  The amount of combustion of hot water supply burner 21 is controlled by which one or a plurality of burners among burner A, burner B, and burner C are burned, and the opening of gas proportional valve 42.

  FIG. 3 shows the relationship between the combustion amount of the hot water supply burner 21 and the opening degree of the gas proportional valve 42. In the range where the required combustion amount is F1 or less, the second hot water supply gas electromagnetic valve 44 and the third hot water supply gas electromagnetic valve 45 are closed, the first hot water supply gas electromagnetic valve 43 is opened, and only the burner A is burned. The amount of combustion inside is adjusted by the opening degree of the gas proportional valve 42.

  In the range where the required combustion amount exceeds F1 and is equal to or less than F2, the third hot water gas electromagnetic valve 45 is closed, the first hot water gas electromagnetic valve 43 and the second hot water gas electromagnetic valve 44 are opened, and the burners A and B are burned. The combustion amount within the above range is adjusted by the opening degree of the gas proportional valve 42.

  In the range where the required combustion amount exceeds F2, the first hot water supply gas electromagnetic valve 43, the second hot water supply gas electromagnetic valve 44, and the third hot water supply gas electromagnetic valve 45 are all opened to burn the burners A, B, C. The amount of combustion within the range is adjusted by the opening of the gas proportional valve 42.

  As shown in FIG. 3, the burner A closest to the bath heat exchanger 32 is preferentially burned. That is, the heat transfer from the hot water supply heat exchanger 22 side to the bath heat exchanger 32 through the fins 25 described in FIG. 2 is efficiently generated even with a small amount of combustion. Preferential combustion of the burner A may be performed at least during simultaneous use (simultaneous combustion) of hot water supply and bath reheating.

<Pouring operation>
The pouring operation is executed when an automatic bath operation or pouring instruction is received from the remote controller. In the pouring operation, the control unit opens the pouring electromagnetic valve 67 and ignites the hot water supply burner 21 to burn the combustion gas in the hot water supply burner 21. Thus, the water supplied from the water supply source is heated by receiving the heat of the exhaust from the hot water supply burner 21 when passing through the hot water latent heat exchanger 22b and the hot water sensible heat exchanger 22a. When it is open, it is mixed with the water supply from the bypass pipe 54, then flows into the bath return pipe 60 through the connecting pipe 66, and is poured into the bathtub 2 through the bath return pipe 60 and the bath outlet pipe 61. Even in the pouring operation, the bypass mixing valve 55 is normally controlled to be closed.

  When the bathtub 2 reaches a set water level, the pouring operation is stopped. Specifically, the hot water solenoid valve 67 is closed and the supply of the combustion gas to the hot water supply burner 21 is shut off to stop the combustion of the hot water supply burner 21.

<Bath chasing action>
The bath reheating operation is performed when the temperature of the bath water in the bathtub 2 is raised to the bath set temperature after the above-described pouring operation is performed based on the instruction for automatic bath operation and the water is filled to the set water level. Alternatively, it is executed when the temperature of the hot water in the bathtub 2 is raised during the automatic operation of the bath to maintain the bath set temperature, or when a follow-up instruction is received from the user.

  In the bath reheating operation, the control unit turns on the circulation pump 62 and ignites the bath burner 31 to burn the combustion gas in the bath burner 31. The bath water in the bathtub 2 is taken into the bath return pipe 60 by the action of the circulation pump 62, and the bath return pipe 60, the bath latent heat exchanger 32 b, the bath sensible heat exchanger 32 a, and the bath outlet pipe 61. It circulates so that it may return to bathtub 2 via. The bath water is heated by receiving the heat of the exhaust from the bath burner 31 when passing through the bath latent heat exchanger 32b and the bath sensible heat exchanger 32a.

<Simultaneous use of hot water supply and bath chasing>
The simultaneous use of hot water supply and bath reheating occurs, for example, when a hot water tap is opened and hot water is supplied during a bath reheating operation. In simultaneous use of hot water supply and bath reheating, the opening degree of the gas proportional valve 42 is controlled based on the hot water supply operation (prioritizing the hot water supply side). That is, the opening degree of the gas proportional valve 42 is controlled in accordance with the characteristics shown in FIG.

  At this time, when the opening of the gas proportional valve 42 is small and the temperature of the bath water returning from the bathtub 2 is low, the bath heat exchanger 32 (particularly, the sensible heat exchanger 32a for bath) There is a possibility that the temperature does not rise so much and moisture in the combustion exhaust is condensed in the bath sensible heat exchanger 32a.

Therefore, the bath water heater 10 according to the present embodiment effectively uses the heat transfer from the hot water supply heat exchanger 22 side to the bath heat exchanger 32 through the fins 25 and the like, which has been described with reference to FIG. Suppresses the occurrence of Specifically, when hot water and bath reheating are used at the same time, the opening of the bypass mixing valve 55 is increased (mixed with a lot of water) compared to the case of using hot water alone. Create hot water.

  FIG. 4 shows a process flow for controlling the opening degree of the bypass mixing valve 55. It is checked whether or not hot water is used alone (step S101). When hot water is used alone (step S101; Yes), the bypass mixing valve 55 is closed (step S102). Thereby, all the hot water to be supplied is heated through the hot water supply heat exchanger 22. In this state, the control unit controls the combustion amount of the hot water supply burner 21 so that hot water at the hot water supply set temperature is discharged. Instead of closing, the bypass mixing valve 55 may be controlled to be opened by a small amount.

  On the other hand, when hot water supply and bath reheating are used simultaneously (step S101; No), the opening degree of the bypass mixing valve 55 is increased as compared to the case of using hot water supply alone (step S103). As a result, the amount of water supplied through the hot water supply heat exchanger 22 is reduced. For example, when the hot water supply set temperature is 45 ° C., 80 ° C. hot water is discharged from the hot water supply heat exchanger 22, and the hot water at the hot water supply set temperature is obtained by mixing the 80 ° C. hot water through the bypass pipe 54. The opening degree of the bypass mixing valve 55 is controlled so that the hot water is discharged.

  In this way, the heat efficiency of the hot water supply heat exchanger 22 is lowered, but the hot water supply heat exchanger 22 is heated by that amount, and the hot water supply heat exchanger 22 through the fins 25 and the like to the bath heat exchanger 32. The amount of heat transferred increases. As a result, the temperature of the bath heat exchanger 32 increases, and condensation in the bath heat exchanger 32 is prevented / suppressed.

  Next, when the hot water supply side and the bath side are burned simultaneously, the bath sensible heat exchanger 32a determines whether or not there is a possibility of condensation, and if it is determined that there is a possibility of condensation, the bath The case where the control which interrupts the combustion of the burner 31 is performed is demonstrated.

  In determining whether or not there is a possibility of condensation, the amount of heat transferred from the hot water supply heat exchanger 22 side to the bath heat exchanger 32 through the fins 25 and the like described in FIG. 2 is taken into consideration. That is, the amount of heat transmitted from the hot water supply heat exchanger 22 side to the bath heat exchanger 32 is further added to the temperature detected by the bath return temperature sensor 64 and the combustion amount of the bath burner 31, and dew condensation occurs in the hot water supply latent heat exchanger 22b. It is determined whether or not to do.

  The amount of heat transferred from the hot water supply heat exchanger 22 side to the bath heat exchanger 32 is determined when the bypass mixing valve 55 is closed (S102 in FIG. 4) and when the bypass mixing valve 55 is largely opened (S103 in FIG. 4). Therefore, the presence or absence of condensation when the bypass mixing valve 55 is closed and the presence or absence of condensation when the bypass mixing valve 55 is opened are determined.

  Specifically, the detected temperature of the bath return temperature sensor 64 and the amount of combustion of the bath burner 31 for each of the case where the hot water supply is performed with the bypass mixing valve 55 closed by simultaneous combustion and the case where the hot water supply is performed with the bypass mixing valve 55 wide open. The presence or absence of condensation is determined based on the combustion amount of the hot water supply burner 21.

  By the way, as shown in FIG. 3, since the opening degree of the gas proportional valve 42 with respect to the combustion amount of the hot water supply burner 21 is uniquely determined, if the combustion amount of the hot water burner 21 is determined, the hot water supply burner 21 and the gas proportional valve 42 are shared. The amount of combustion of the bath burner 31 to be used is also determined. Therefore, determining the presence or absence of dew condensation based on the temperature detected by the bath return temperature sensor 64 and the amount of combustion of the hot water supply burner 21 is based on the temperature detected by the bath return temperature sensor 64, the amount of combustion of the bath burner 31, and the hot water supply burner 21. This is equivalent to determining the presence or absence of condensation based on the amount of combustion.

  Therefore, in the present embodiment, the detected temperature of the bath return temperature sensor 64 (bath return temperature) and the temperature of the hot water supply burner 21 are shown in FIG. Data indicating the relationship between the combustion amount (hot water supply side combustion amount) and the presence or absence of condensation is obtained in advance by varying the bath return temperature and the hot water side combustion amount in various ways. Correlation data in a look-up table format is created in which the detected temperature (bath return temperature) and the combustion amount of the hot water supply burner 21 (hot water supply side combustion amount) are input values and the possibility of condensation is output. The correlation data when the bypass mixing valve 55 is closed is first correlation data 71, and the correlation data when the bypass mixing valve 55 is largely opened is second correlation data 72.

  The detected temperature of the current bath return temperature sensor 64 and the combustion amount of the hot water supply burner 21 set by the control unit are input to the first correlation data 71 and the second correlation data 72, respectively. The output value indicating the presence or absence of condensation is obtained from each of the second correlation data 72. The output value of the first correlation data 71 indicates the presence or absence of condensation when the bypass mixing valve 55 is closed and the combustion is performed simultaneously. The output value of the second correlation data 72 is the simultaneous combustion when the bypass mixing valve 55 is opened. Indicates the presence or absence of condensation when allowed to occur.

  Note that which burner A, B, or C is burned with respect to the amount of combustion of the hot water supply burner 21 is determined in advance, so which burner is uniquely determined from the amount of combustion of the hot water supply burner 21. . Therefore, the first and second correlation data take into account which burner is burning.

  For example, as shown in FIG. 3, only burner A is initially controlled. When the combustion amount exceeds F1, burners A and B are controlled, and when F2 is exceeded, control is performed as A + B + C. When F1 is exceeded, the contents of the correlation data are different between the burners B and C, and when F2 is exceeded, control is performed as A + B + C. If the burn amount of the hot water supply burner 21 does not uniquely correspond to which burner is burned, what burner is burned may be added to the determination element for the presence or absence of condensation as another parameter.

  Moreover, although the air volume of the combustion fan 11 is changed according to the combustion amount of the hot water supply burner 21, the air volume with respect to each combustion amount of the hot water supply burner 21 is also uniquely determined. Therefore, if the combustion amount of the hot water supply burner 21 is used as a parameter, the air volume of the combustion fan 11 is also taken into consideration in the determination of the possibility of condensation. When the combustion amount of the hot water supply burner 21 and the air volume of the combustion fan 11 are not uniquely determined, the air volume of the combustion fan 11 may be added to the determination element as another parameter.

  FIG. 6 is a flowchart showing a process in which the controller of the bath water heater 10 determines the possibility of condensation and controls the opening and combustion of the bypass mixing valve 55. This process is executed when the hot water supply side is used.

  It is determined whether or not a single hot water supply is used (step S201). If the single hot water supply is used (step S201; Yes), the bypass mixing valve 55 is closed to perform a hot water supply operation (step S202).

  In the case of simultaneous use of hot water supply and bath reheating (step S201; No), the first correlation that is the correlation data when the bath return temperature, the hot water supply side combustion amount (combustion amount of the hot water supply burner 21), and the bypass mixing valve 55 are closed. A determination result of the presence or absence of condensation is acquired from the data 71 (step S203). If the determination result indicates that there is no possibility of condensation (step S204; No), the hot water supply burner 21 and the bath burner 31 are simultaneously burned, and the hot water supply operation in which the bypass mixing valve 55 is closed and the bath reheating operation are performed in parallel. (Step S205).

  When there is a possibility of condensation due to simultaneous use (simultaneous combustion) with the bypass mixing valve 55 closed (step S204; Yes), the bath return temperature, the hot water supply side combustion amount, and the opening of the bypass mixing valve 55 are large. A determination result of the presence or absence of condensation is acquired from the second correlation data 72, which is correlation data (step S206).

  If the determination result indicates that there is no possibility of condensation (step S207; No), the hot water supply burner 21 and the bath burner 31 are simultaneously burned, the opening of the bypass mixing valve 55 is increased, and the hot water supply operation and the bath reheating operation are performed. Are performed in parallel (step S208). If there is a possibility of condensation due to simultaneous use (simultaneous combustion) even when the opening of the bypass mixing valve 55 is large (step S207; Yes), the supply of the combustion gas to the bath burner 31 is shut off, and the hot water supply burner Only the hot water supply 21 is operated by burning only 21 (step S209). At this time, the bypass mixing valve 55 is desirably closed, but the opening degree may be arbitrary, and the hot water supply operation may be performed with the opening degree set large.

  Thus, when using hot water and bath reheating at the same time, if there is no possibility of condensation with the bypass mixing valve 55 closed, hot water is supplied with the bypass mixing valve 55 closed. The thermal efficiency at 22 can be increased. On the other hand, if the bypass mixing valve 55 is closed and there is a possibility of condensation due to simultaneous use of hot water supply and bathing, if the opening of the bypass mixing valve 55 is increased, there is no possibility of condensation. Since the opening of the bypass mixing valve 55 is set to a large value and simultaneous use (simultaneous combustion) is performed, the number of cases where the bath replenishment (combustion of the bath burner 31) is interrupted to prevent condensation is reduced, and the bath follow-up is reduced. Prolonging the time required for sowing can be suppressed.

  The embodiment of the present invention has been described with reference to the drawings. However, the specific configuration is not limited to that shown in the embodiment, and there are changes and additions within the scope of the present invention. Are also included in the present invention.

  In the embodiment, the hot water supply burner 21 and the bath burner 31 are exemplified as the types having a latent heat exchanger and a sensible heat exchanger, but the present invention is also applied to a sensible heat exchanger alone.

  In the embodiment, the temperature detected by the bath return temperature sensor 64 is used as a material for determining the presence or absence of dew condensation. However, the sensible heat exchange for the bath is performed after leaving the bath latent heat exchanger 32b of the bath heat exchanger 32. A temperature sensor that detects the temperature of the bath water before entering the vessel 32a may be provided, and the temperature detected by the temperature sensor may be used as the determination material.

  In the embodiment, the presence / absence of dew condensation is determined using the correlation data 71 and 72 in the look-up table format. However, if a function corresponding to the correlation data can be defined, the bath return temperature, the hot water supply side combustion amount are included in the function. And the presence or absence of condensation may be determined from the calculation result of the function.

DESCRIPTION OF SYMBOLS 2 ... Bathtub 3 ... Bathtub water intake 4 ... Bathtub water discharge port 10 ... Bath water heater 11 ... Combustion fan 12 ... Exhaust port 13 ... Combustion chamber 14 ... Partition plate 15 ... Drain receptacle 16 ... Collection pipe 17 ... Neutralizer 21 ... Hot-water supply burner (Burner A, B, C)
22 ... Heat exchanger for hot water supply 22a ... Sensible heat exchanger for hot water supply 22b ... Latent heat exchanger for hot water supply 24 ... Heat receiving pipe 25 ... Fin 31 ... Bath burner 32 ... Heat exchanger for bath 32a ... Sensible heat exchange for bath 32b ... Bath latent heat exchanger 40 ... Gas supply pipe 41 ... Original gas solenoid valve 42 ... Gas proportional valve 43 ... First hot water gas solenoid valve 44 ... Second hot water gas solenoid valve 45 ... Third hot water gas solenoid valve 46 ... Bath gas solenoid valve 50 ... Water supply pipe 51 ... Hot water supply pipe 52 ... Water quantity sensor 53 ... Water quantity servo 54 ... Bypass pipe 55 ... Bypass mixing valve 56 ... Heat exchange temperature sensor 57 ... Hot water temperature sensor 60 ... Bath return pipe 61 ... Bath return Pipe 62 ... Circulation pump 63 ... Flowing water switch 64 ... Bath return temperature sensor 65 ... Bathing temperature sensor 66 ... Connecting pipe 67 ... Pouring solenoid valve 68 ... Check valve 71 ... First correlation data 72 ... Second phase Seki data

Claims (6)

A heat exchanger for hot water supply,
A hot water supply burner for heating the hot water supply heat exchanger;
A heat exchanger for bathing, which is thermally connected to the heat exchanger for hot water supply,
A bath burner for heating the bath-heating heat exchanger;
A proportional valve for adjusting the amount of gas supplied to the hot-water supply burner and the bath burner;
A hot water supply path in which the inlet side is connected to a water supply source, the outlet side is connected to a hot water outlet through the hot water heat exchanger,
A bypass path for connecting the inlet side and the outlet side of the hot water path, bypassing the hot water heat exchanger,
A mixing valve for adjusting the amount of water supplied to the bypass path;
A bath reheating circuit for taking in the bathtub water from the bathtub and returning it to the bathtub through the bath reheating heat exchanger;
A circulation pump for circulating bath water in the bath reheating circuit;
A controller for controlling the combustion of the hot water burner and the bath burner and the opening of the mixing valve;
The controller controls the opening of the proportional valve by giving priority to the hot water supply side when performing hot water supply and bath reheating at the same time, and increases the amount of water supplied to the bypass path as compared to the case of using hot water alone. The bath water heater is characterized in that the opening of the mixing valve is adjusted to produce hot water at a hot water supply set temperature. If the controller controls the opening of the mixing valve in the same way as when using only hot water supply when performing hot water supply and bath reheating at the same time, it is determined whether or not condensation occurs in the heat exchanger for bath reheating Then, when it is determined that condensation occurs, the opening of the mixing valve is adjusted so as to increase the amount of water supplied to the bypass path as compared to the case of using hot water alone. Water heater. The hot water burner is composed of a plurality of sub-burners,
The control unit, when performing hot water supply and bath reheating at the same time, preferentially burns one of the plurality of sub-burners closest to the bath reheating heat exchanger. The bath water heater described in 1. The control unit adjusts the opening of the mixing valve to increase the amount of water supplied to the bypass path when hot water and bath reheating are performed at the same time as compared with the case of using only hot water, and hot water at a hot water supply set temperature. 4. The gas supply to the hot water burner is shut off when it is determined whether or not condensation occurs in the bath-heating heat exchanger even if it is produced. The bath water heater as described in any one of. A temperature sensor that detects the temperature of water entering the heat exchanger for bathing the bath;
The control unit performs the determination by adding the amount of heat transmitted from the hot water supply heat exchanger side to the bath reheating heat exchanger to the detected temperature of the temperature sensor and the combustion amount of the bath burner. The bath water heater according to claim 2 or 4. The bath water heater according to any one of claims 1 to 5, wherein the bath-heating heat exchanger is a latent heat recovery type heat exchanger that recovers latent heat and sensible heat.