JP5123405B2 - Drain discharge device and water heater - Google Patents

Description

  The present invention relates to a drain discharge device that discharges drain generated inside a water heater, and a water heater provided with the drain discharge device.

  There exists a thing of the structure which heats the water supplied from the outside with the heat exchanger for collect | recovering latent heat in the water heater for performing the hot water supply to a bathtub. In the water heater having this configuration, since drain is generated when the latent heat is recovered, a drain tank or the like is generally provided so that the drain can be recovered and discharged.

  In recent years, a hot water heater equipped with a heat retaining function that reheats hot water in the bathtub while circulating it in the circulation path has been proposed with a technology for automatically discharging the drain stored in the drain tank through this circulation path. (See Patent Document 1).

  In this technique, a water passage (22 to 23) that heats the supplied water and passes the water to the bathtub, and a circulation passage that circulates hot water stored in the bathtub using a part of the water passage as a shared section (23) ( 23 to 24) and one way connection port is connected to the drain drainage channel (50) extending from the drain tank, and the remaining two connection ports are connected to the circulation path, thereby connecting the drain tank and the circulation path. (29) and a check valve (51) for preventing a back flow from the circulation path to the drain tank side.

  Further, in this technique, in a state where hot water does not exist in the bathtub, a flow path from the drain tank to the water passage side is formed by a three-way valve, and then the circulation pump (26) of the water passage is operated and stored in the drain tank. Drain discharge is realized by distributing the drained drain to the bathtub through the circulation path and the water passage (see FIG. 5 of Patent Document 1).

JP 2008-8487 A

  In the above technique, the drain passage is closed by the three-way valve and the circulation pump is operated in a state in which the flow path from the circulation path to the water passage is formed (FIG. 6 of the cited document 1; first purge operation), and the three-way valve. Drain is discharged in the circulation path by sequentially performing the control of supplying water from the water passage with the circulation path closed and the flow path from the drain tank to the water passage side being formed (Fig. 7; purge operation). The path used for the cleaning is to be cleaned.

  However, in the first purge operation, the hot water remaining in the circulation path is merely flowed to the bathtub side, and it cannot be said that the hot water that can sufficiently wash the inside of the circulation path is flowed. For this reason, the region where hot water does not circulate in the purge operation following the previous purge operation, that is, the region from the connection portion with the drain passage in the circulation path to the shared portion with the water passage becomes a problem of insufficient cleaning. There is a point.

  Furthermore, the drain drainage channel is not washed during the previous purge operation or the purge operation. For this reason, it was cut off from the state where the drain drainage channel and the circulation channel were communicated by the three-way valve, such as when switching from the purge operation state (Fig. 7) to the hot water filling operation state (Fig. 3). When switching to the state, drain existing in the drain drainage channel flows out to the circulation path side, and there is a possibility that hot water flowing through the circulation path is contaminated.

  The present invention has been made in order to solve such problems, and its purpose is to make it possible to more appropriately clean the paths used for drainage in the circulation path and the water passage than before. Is to provide technology.

  In order to solve the above problems, a first invention (Claim 1) is a path for supplying water supplied from the outside, and a hot water supply path provided with a heat exchanger for collecting latent heat in a part of the path; A water passage for passing hot water supplied from the hot water supply passage through the water supply valve to the bathtub side, and a path for circulating hot water stored in the bathtub with a circulation pump and returning it to the bathtub, A heat exchanger is provided in a part of the path, a part of the path in the path is a shared path for leading hot water from the water flow path to the bathtub, and a drain generated from the heat exchanger. A drain discharge device provided in a water heater provided with a drain tank for storage.

  And each of the inflow path for flowing hot water into the drain tank and the discharge path for discharging drain from the drain tank are connected to the circulation path, and the flow direction of hot water in the communication section is switched. Accordingly, the passage forming portion that forms a circulation route through the communication portion, and the water passage is closed by the water passage valve, and from the discharge passage to the downstream side of the circulation passage through the communication portion. By operating the circulation pump in a state where the flow path is formed in the path forming part, the drain stored in the drain tank is circulated from the drain tank to the circulation path via the communication part. The flow control valve and a flow path from the downstream side of the circulation path to the inflow path in the communication part are formed in the path formation part, and the flow control valve Washing control for allowing hot water to flow toward the downstream side of the circulation path and for flowing hot water from the circulation path to the drain tank via the communication part by opening the water passage and performing water flow. Means.

  In the case of the drain discharge device according to this configuration, by operating the circulation pump in a state in which a circulation path from the discharge path to the downstream side of the circulation path is formed through the communication section, the drain tank is connected via the communication section. Thus, the drain stored in the drain tank can be circulated to the circulation path and discharged from the downstream side of the circulation path.

  Then, in a state where a circulation path from the downstream side of the circulation path to the inflow path is formed in the communication part, by passing water from the water passage, hot water is supplied from the circulation path to the drain tank via the communication part. It can be distributed. In this way, part of the hot water flowing from the water passage goes to the downstream side of the circulation path, and the other goes from the upstream side of the circulation path to the drain tank through the communication part and the inflow path. Thus, the paths through which the drain stored in the drain tank has passed can be cleaned appropriately.

  In this configuration, the timing of the start of control for circulating and discharging the drain to the circulation path via the communication unit is not particularly limited, but for example, every predetermined time, predetermined time, the operating state of the heat exchanger, What is necessary is just to start according to the drain amount etc. which were stored by the drain tank.

Here, in order to start draining according to the amount of drain stored in the drain tank, for example, the following second configuration (claim 2) can be considered.
In the second configuration, the apparatus includes a drain detection unit that detects a drain amount stored in the drain tank, and the discharge control unit has reached a predetermined upper limit of the drain amount detected by the drain detection unit. In this case, the circulation of the drain from the drain tank to the circulation path is started.

With this configuration, drainage from the drain tank can be started at the timing when the amount of drain stored in the drain tank reaches the upper limit.
In addition, in each of the above-described configurations, the timing for ending the drain discharge described above is not particularly limited. For example, according to the duration of drain discharge, the operating state of the heat exchanger, the amount of drain stored in the drain tank, and the like. To finish.

Here, in order to terminate drain discharge in accordance with the amount of drain stored in the drain tank, for example, the following third configuration (claim 3) can be considered.
In the third configuration, the discharge control means distributes the drain from the drain tank to the circulation path until the amount of drain stored in the drain tank reaches a lower limit defined as a value larger than zero. Let

  If it is this structure, since the discharge | emission of the drain mentioned above will be complete | finished at the timing when the quantity of the drain stored in the drain tank became the lower limit value larger than 0, it will be a part which reaches a circulation path via a communication part. Drain discharge can be terminated in a state in which the route and the circulation path are filled with drain (or hot water).

  Therefore, it is possible to prevent problems (so-called air biting and generation of abnormal noise caused by the air) that hinder continuous air circulation by the circulation pump by the air in the circulation path. Further, since the inside of the circulation pump is also filled with drain (or hot water), a non-self-priming pump that requires priming water at the start of operation can be used, and the range of design can be expanded.

  In this configuration, whether or not the drain amount has reached the lower limit is not limited to the method of directly detecting the drain amount as in the second configuration, but the duration of drain discharge, the heat exchanger You may determine by the method of detecting (estimating) indirectly according to an operation state etc.

  In addition, as a configuration for ending drain discharge according to the amount of drain stored in the drain tank, for example, when the circulation pump includes means for detecting the air engagement and stopping the circulation pump. If so, it is conceivable to end drainage by intentionally causing air biting at the timing when the amount of drain reaches a predetermined lower limit.

For this purpose, each of the above-described configurations may be configured as a fourth configuration (claim 4) shown below.
4th structure WHEREIN: The edge part opening in the said inflow channel is connected to the said drain tank in the position away from the bottom face in this drain tank predetermined height.

  With this configuration, the end opening in the inflow passage is connected to a position that is a predetermined height away from the bottom surface inside the drain tank, so that the liquid level of the drain stored in the drain tank is lower than the opening end. When the drain amount decreases until it is located at the position, the air inside the drain tank is directed from the opening end portion to the communicating portion through the inflow path. At this time, since the circulation pump is in operation, the air that has reached the communicating portion reaches the circulation pump together with the surrounding drain, so that the air pumping can be detected and the circulation pump can be stopped.

  For this reason, in the above-described configuration, the drain position in which the drain discharge is stored in the drain tank is determined by setting the connection position of the end opening in the inflow channel to a position corresponding to the drain amount at which the drain discharge should be terminated. Can be terminated at a timing when becomes a desired lower limit.

  In addition, as a configuration for intentionally causing air biting at a timing when the drain amount reaches a predetermined lower limit value and terminating drainage, a fifth configuration described below as the first to third configurations is as follows. (Claim 5).

  In the fifth configuration, the inflow path penetrates into the drain tank, and an opening that communicates the inflow path from the inside to the outside is formed at a position at least a predetermined height away from the bottom surface inside the drain tank. ing.

  With this configuration, since an opening that communicates the inside and outside of the inflow passage is formed at a position that is a predetermined height away from the bottom surface inside the drain tank, the liquid level of the drain stored in the drain tank is more than the opening. When the drain amount decreases until it is located below, the air inside the drain tank is directed from this opening to the communicating portion via the inflow path. At this time, since the circulation pump is operating, the air that has reached the communicating portion reaches the circulation pump together with the surrounding drain, and as a result, the air pumping can be detected and the circulation pump can be stopped.

  For this reason, in the above configuration, the amount of drain stored in the drain tank is determined by setting the position of the opening in the inflow passage according to the amount of drain to be discharged. Can be terminated at a timing when becomes a desired lower limit.

  In addition, as the above-mentioned “means for detecting the air engagement and stopping the circulation pump”, if the circulation pump itself has such a function, a means for stopping by the function may be adopted. In addition, if a water flow switch is provided in a path through which hot water is circulated by the circulation pump, means for stopping the circulation pump when it is detected that the hot water ceases to circulate by the water flow switch. Can be adopted. In addition, air is temporarily mixed in the circulation path as the drain is discharged, but the air can be excluded from the circulation path by the water flow by the circulation control means.

  Further, in each of the above configurations, the start timing of the control for cleaning the path by circulating hot water from the circulation path to the drain tank via the communication section from the circulation path is not particularly limited. Depending on the timing after drain discharge is started (during drain discharge operation or after drain discharge is completed), every predetermined time, at predetermined time, the operating state of the heat exchanger, the amount of drain stored in the drain tank, etc. Just start.

Moreover, in each said structure, since a fixed amount of hot water is stored in a drain tank by washing | cleaning of a path | route, it is good also as discharging this hot water.
As a configuration for this, each of the above configurations may be configured as a sixth configuration (claim 6) shown below.

  In the sixth configuration, the discharge control means closes the water flow path by the water flow valve after the hot water flow by the cleaning control means, and downstream of the circulation path from the drain tank through the communication portion. In the state where the flow path leading to the side is formed in the path forming part, the circulation pump is operated, so that the drain tank is stored in the drain tank from the drain tank to the circulation path via the communication part. Distribute hot water.

If it is this structure, the capacity | capacitance which can store the drain which may generate | occur | produce after that can be ensured by discharging | emitting the hot water stored by the drain tank by the washing | cleaning of a path | route.
In this configuration, after the hot water is discharged after the cleaning of the path, the cleaning of the path may be performed again, and a cycle including the discharging of the hot water and the cleaning of the path is performed for the time. It is good also as making the quantity of the hot water finally stored by a drain tank less than fixed by repeating several times, shortening gradually.

  Further, in each of the above configurations, the specific configuration of the path forming unit is not particularly limited as long as the channel forming unit can form a distribution path via a communication part between the inflow path and the discharge path and the circulation path. For example, if the communication portion has a joining path that joins the inflow path and the discharge path to reach the circulation path, the above-described respective configurations are as described below in the seventh configuration (Claim 7). It is good to do so.

  In the seventh configuration, the communication portion between each of the inflow path and the discharge path and the circulation path has a merge path that joins the inflow path and the discharge path to reach the circulation path, The path forming unit includes at least a first path forming valve and a second path forming valve. The first path forming valve has a communication portion between the circulation path and the merging path at least from one of the upstream side and the downstream side in the circulation path to the other, the merging path and the circulation path. It is a valve body that switches to one of the flow paths from one of the downstream sides to the other, and the second path formation valve is configured to flow hot water from the merge path to the drain tank in the discharge path. It is a valve body to block.

  And the said discharge control means is the state which closed the said water flow path by the said water flow valve, and connects the said circulation path and the said merge path by the said 1st path | route formation valve, the said merge path and the said circulation After switching the flow path from one of the downstream sides to the other of the path, the drain pump is operated to move the drain tank from the drain path and the communication portion to the circulation path. By flowing the drain stored in the tank, the cleaning control means opens the water passage by the water passage valve and performs water passage, so that the circulation passage passes through the communication portion and the inflow passage. Hot water is circulated through the drain tank.

  If it is this structure, after forming the distribution path via the communication part of each of the inflow path and the discharge path and the circulation path by the functions of the first path formation valve and the second path formation valve, the drain including the path cleaning is included. The discharge operation can be realized.

  In particular, the second path forming valve provided in the discharge path prevents the flow of hot water from the merging path to the drain tank in the discharge path. Can be prevented.

Further, in this configuration, an eighth configuration (claim 8) described below is preferable.
In an eighth configuration, the path formation unit includes at least the first path formation valve, the second path formation valve, and a third path formation valve, and the third path formation valve includes the In the inflow path, it is a valve body that prevents the flow of hot water from the drain tank toward the merging path.

  With this configuration, the third path forming valve provided in the inflow path prevents the flow of drain from the drain tank to the merging path in the inflow path. Therefore, without controlling the opening and closing of the inflow path, Unintended backflow can be prevented.

  Moreover, in order to solve the said subject, the water heater which concerns on 9th structure (Claim 9) is a path | route for supplying the water supplied from the outside, The heat exchanger which collect | recovers latent heat in a part of this path | route A hot water supply path provided with a hot water supplied from the hot water supply path through the water supply valve to the bathtub side, and circulating hot water stored in the bathtub with a circulation pump to the bathtub. A circulation path that is a return path, and includes a heat exchanger in a part of the path, and a section in the path is a shared section that guides hot water from the water passage to the bathtub, and the exchanger The drain tank which stores the drain which generate | occur | produces from, and the drain discharge apparatus which concerns on any one of the said 1st to 8th structure are provided.

  If it is a water heater which concerns on this structure, the water heater which has the effect | action and effect similar to the said 1st-8th structure can be obtained.

It is a figure which shows the whole structure of a water heater. It is a figure which shows the drain storage part in 1st Embodiment. It is a flowchart which shows drain discharge control. It is a figure which shows the distribution | circulation state of the hot water in drain discharge control. It is a flowchart which shows the modification of the drain discharge control in 1st Embodiment. It is a figure which shows the modification of the drain storage part in 1st Embodiment. It is a figure which shows the drain storage part in 2nd Embodiment. It is a figure which shows the modification of the drain storage part in 2nd Embodiment. It is a figure which shows the drain storage part in another embodiment.

Embodiments of the present invention will be described below with reference to the drawings.
(1) 1st Embodiment (1-1) Whole structure The hot water heater which concerns on 1st Embodiment is stored in the hot water supply part 1 which heats the supplied water, and supplies hot water, and the bathtub 210, as shown in FIG. A heat retaining unit 3 that retains the heated water, a connection unit 5 that connects the hot water supply unit 1 and the heat retaining unit 3, a control unit 7 that controls the operation of each unit, and a drain storage unit 9 that stores drain generated in the water heater. And.

  The hot water supply unit 1 is a gas burner 17 that burns fuel gas to generate combustion gas, a hot water supply passage 11 through which water supplied from the outside flows, and a latent heat from the combustion gas that is provided in the hot water supply passage 11 By the sub heat exchanger 13 that transfers heat to the water flow, the main heat exchanger 15 that recovers sensible heat from the combustion gas in the state provided in the hot water supply path 11 and transfers the heat to the internal water flow, and the sub heat exchanger 13 A neutralizer 19 is provided for neutralizing drain (acid condensate containing nitrogen oxides or sulfur oxides) generated during the recovery of latent heat.

  Among these, the auxiliary heat exchanger 13 and the main heat exchanger 15 are arranged in the order of the auxiliary heat exchanger 13 and the main heat exchanger 15 from the upstream side to the downstream side of the water flow in the hot water supply channel 11. The main heat exchanger 15 and the sub heat exchanger 13 are arranged in this order from upstream to downstream in the flow of combustion gas by the gas burner 17. Thereby, the sensible heat of the combustion gas is recovered by the main heat exchanger 15 arranged on the upstream side of the combustion gas, and the latent heat of the combustion gas (and the sensible heat that could not be recovered by the main heat exchanger 15) is the combustion gas. It will be collect | recovered by the auxiliary heat exchanger 13 arrange | positioned in the downstream of this.

  Further, in the hot water supply passage 11, a strainer 25 that filters the supplied water, a water amount sensor 27 that detects the amount of supplied water, and a water amount control valve 29 that controls the amount of water in the hot water supply passage 11 are provided in order from the water supply source. It has been.

  Further, the hot water supply passage 11 is configured to supply hot water to the hot water tap 220 on the downstream side thereof and also supply hot water to the connection portion 5. The connecting part 5 is a water passage 51 for passing hot water supplied from the hot water supply path 11 toward the bathtub 210 side of the heat retaining part 3, and a passage for controlling the water flow to the bathtub 210 side by opening and closing the water passage 51. A water valve 53 is provided.

  The heat retaining unit 3 circulates the hot water stored in the bathtub 210 and returns it to the bathtub 31, the circulation pump 33 that circulates the water stored in the bathtub 210 between the bathtub 210 and the circulation path 31, A water flow switch 35 provided on the downstream side of the circulation pump 33 in the circulation path 31, a heat exchanger 37 provided on the downstream side of the circulation path 31, and a gas burner 39 for heating the path provided with the heat exchanger 37 in the circulation path 31. Etc. A part of the circulation path 31 is a section A shared with the water passage 51.

Among these, the circulation pump 33 is provided on the upstream side of the path through which water circulates in the circulation path 31, specifically, between the shared section A with the water passage 51 and the heat exchanger 37.
Further, the circulation path 31 has a drainage switching valve that switches between a circulation path that communicates the downstream side of the circulation path 31 to the bathtub 210 and a circulation path that communicates the circulation path 31 to a drain port (not shown). 41 is provided. The drainage switching valve 41 forms a circulation path that connects the circulation path 31 to the bathtub 210 in the initial state, and switches the circulation path in response to a command from the control unit 7.

  The control unit 7 includes a controller 71 that controls the operation of each unit by a built-in microcomputer, a kitchen remote controller 73 that receives user operations outside the bathroom such as a kitchen, a bathroom remote controller 75 that receives user operations inside the bathroom, and the like. Yes. Among these, the controller 71 controls the operation of each unit in accordance with a program stored in a built-in memory.

  As shown in FIG. 2, the drain storage unit 9 collects and stores the drain generated from the auxiliary heat exchanger 13 of the hot water supply unit 1 and neutralized by the neutralizer 19, to the drain tank 91 and the drain tank 91. An inflow passage 93 having one end connected to the upper portion of the drain tank 91 to allow the hot water to flow in, a discharge passage 95 having one end connected to the bottom of the drain tank 91 to discharge the hot water from the drain tank 91, the inflow passage 93, and the discharge A path forming unit 100 that forms a flow path in a communication part between the merging path 97 that joins the flow paths on the other end side of the path 95 and communicates with the circulation path 31, the inflow path 93 and the discharge path 95, and the circulation path 31. Etc. In the drain tank 91, a water level sensor 99 for detecting the amount of stored drain (or hot water) is provided.

  Among these, the merging path 97 is a shared path formed by merging the other end sides of the inflow path 93 and the discharge path 95, and performs both functions of the inflow path 93 and the discharge path 95. By communicating with the circulation path 31, a part of the communication section between the inflow path 93 and the discharge path 95 and the circulation path 31 is formed. In addition, although it does not specifically limit about the communication location with respect to the circulation path 31, In this embodiment, it is connected to the shared area A with the water flow path 51 in the circulation path 31. FIG.

  Further, the path forming unit 100 includes a flow path from the discharge path 95 to the downstream side of the circulation path 31 as a flow path in the communication section, and an inflow path from the downstream side of the circulation path 31 through the communication section. In the present embodiment, as shown in FIG. 2A, the first path forming valve 101, the second path forming valve 103, The third path forming valve 105 is configured to be able to form these distribution paths.

  More specifically, the first path forming valve 101 is configured such that the flow path in the communication portion is at least a flow path from one of the upstream side and the downstream side in the circulation path 31 to the other, the merge path 97 and the circulation path 31. Is a valve body (so-called three-way valve) that switches to one of the flow paths from one of the downstream sides to the other. The first path forming valve 101 forms a flow path from one of the upstream side and the downstream side in the circulation path 31 to the other in the initial state, and receives a command from the controller 7 (the controller 71). Switch distribution channels. The second path forming valve 103 is a valve body (a so-called check valve) that blocks the flow of hot water from the merging path 97 to the drain tank 91 in the discharge path 95. The third path formation valve 105 is a valve body (a so-called check valve) that blocks the flow of hot water from the drain tank 91 toward the merging path 97 in the inflow path 93.

  In addition to the configuration described above, for example, as shown in FIG. 2B, the path forming unit 100 includes open and closed valve bodies 107 and 109 that close and open the inflow path 93 and the discharge path 95, respectively. It is good also as a structure provided as a 2 path | route formation valve and a 3rd path | route formation valve. In this configuration, as an initial state, any one of the second path forming valve 107 and the third path forming valve 109 may be opened and the other may be closed.

In addition, as shown in FIG. 2 (c), instead of the second path forming valve 103 and the third path forming valve 105, the flow path where the inflow path 93 and the discharge path 95 are merged by the merge path 97 is used. It is good also as a structure which provided the 4th path | route formation valve 111 to form. The fourth path forming valve 111 is at least one of a flow path from one of the merging path 97 and the inflow path 93 to the other and a flow path from one of the discharge path 95 and the merging path 97 to the other. It is a valve body (so-called three-way valve) to be switched, and a state in which any one of the flow paths is formed may be set as an initial state.
(1-2) Drain Discharge Control Hereinafter, control for discharging the drain stored in the drain tank 91 will be described with reference to FIG.

  When the water heater according to the above configuration is in a standby state (power-on), the controller 71 controls the operation of each unit, and whenever it is determined that it is time to start draining in the following s110, the path The drain discharge control including the cleaning is performed repeatedly. Hereinafter, the procedure will be described with reference to FIG.

First, the controller 71 enters a standby state until it is time to start discharging the drain stored in the drain tank 91 (s110: NO).
In the present embodiment, the amount of drain stored in the drain tank 91 is checked based on the output result from the water level sensor 99, and the drain is discharged when the amount exceeds a predetermined threshold value. It is determined that it is time to start. The determination that this timing has been reached is not limited to the amount of drain, for example, that a predetermined time has been reached, that a predetermined time has elapsed, heating to the heat exchangers 13, 15, 37, etc. It may be performed based on the fact that the operation history based on has become a predetermined content.

  Thereafter, when the controller 71 determines that it is time to start draining in s110 (s110: YES), the controller 71 forms a distribution path to drain the drain (s120). Here, the water flow path 53 is closed by the water flow valve 53, and a flow path from the discharge path 95 to the downstream side of the circulation path 31 through the merge path 97 is formed in the path formation unit 100, and the circulation path 31. In order to make the drainage switching valve 41 form a flow path that communicates the downstream side to the drainage port, a command is given to the waterflow valve 53, the path forming unit 100, and the drainage switching valve 41. However, at this time, no command is given to the valve body related to the already formed distribution path.

  Note that the command for the route forming unit 100 differs depending on the configuration of the route forming unit 100. For example, when the second path forming valve 103 and the third path forming valve 105 are configured by check valves (FIG. 2A), the merging path 97 and the circulation path 31 are in relation to the first path forming valve 101. Only a command to form a distribution path from one downstream side to the other is issued.

  In addition, when the second path forming valve 107 and the third path forming valve 109 are configured by an open / close valve body (FIG. 2B), a command similar to the above is issued to the first path forming valve 101. In addition, a command is issued so that the second path forming valve 107 is opened and the third path forming valve 109 is closed.

  Further, when the fourth path forming valve 111 is provided in place of the second path forming valve 103 and the third path forming valve 105 (FIG. 2C), the above is applied to the first path forming valve 101. A similar command is issued, and a command to form a flow path from one of the discharge path 95 and the merge path 97 to the other is issued to the fourth path forming valve 111.

  In this way, after the flow path is formed in s120, the controller 71 starts the flow of hot water through the formed flow path by operating the circulation pump 33 (s130). In s120, a circulation path is formed from the discharge path 95 connected to the drain tank 91 to the downstream side of the circulation path 31 via the merging path 97. Thus, by starting the circulation of the hot water, the drain tank The drain stored in 91 is circulated toward the drain through the circulation path 31 (FIG. 4A).

  Next, it is determined whether or not air is mixed in the circulation path 31 (s135). If air mixing is detected (s135: YES), the process proceeds to s150 described later, and the driving of the circulation pump 33 is stopped. As for air contamination, the on / off state of the water flow switch 35 is detected, and when it is turned off, it is determined that air has entered the circulation path 35, the load of the circulation pump 33 is detected, and the load is For example, a method of determining that air has been mixed when the pressure falls below a certain level.

When the mixing of air is not recognized (s135: NO), it is confirmed whether or not it is time to end the circulation of hot water (s140).
It will be in a standby state until it becomes the timing which should complete | finish the distribution | circulation of the hot water started in said s130 (s140: NO).

  In the present embodiment, when the amount of drain based on the output result from the water level sensor 99 has reached a predetermined lower limit value greater than 0, it is determined that it is time to end the circulation of the hot water. This “lower limit value” is determined in advance as an amount in which drain is sufficiently left over the flow path from the discharge path 95 to the circulation pump 33 and the amount of drain stored in the drain tank 91 is minimized. Is. The determination that this timing has been reached is not limited to the amount of drain, for example, that a predetermined time has been reached, that a predetermined time has elapsed, and that the heat exchangers 13, 15, and 37 are heated. The operation history based on the above may be performed based on the fact that the operation history has become a predetermined content.

  If it is determined in s140 that it is time to end the circulation of hot water (s140: YES), the controller 71 stops the operation of the circulation pump 33, thereby causing the flow path formed in s120. The distribution of hot and cold water is terminated (s150).

  Next, the controller 71 cleans the drain distribution channel (s220). Here, the flow path formation unit 100 is formed with a flow path from the inflow path 93 to the circulation path 31 via the merge path 97 and continuing to the downstream side (circulation pump 31 and heat exchanger 37 side) of the circulation path 31. Therefore, a command is issued to the route forming unit 100. However, if the distribution route is formed at this point, no command is issued to the route forming unit 100.

  In addition, the command with respect to the path | route formation part 100 changes with structures of the path | route formation part 100 like said s120. For example, when the second path forming valve 103 and the third path forming valve 105 are configured by check valves (FIG. 2A), the merging path 97 and the circulation path 31 are in relation to the first path forming valve 101. Only a command to form a distribution path from one downstream side to the other is issued.

  In addition, when the second path forming valve 107 and the third path forming valve 109 are configured by an open / close valve body (FIG. 2B), a command similar to the above is issued to the first path forming valve 101. Further, a command is issued so that the second path forming valve 107 is closed and the third path forming valve 109 is opened.

  Further, when the fourth path forming valve 111 is provided in place of the second path forming valve 103 and the third path forming valve 105 (FIG. 2C), the above is applied to the first path forming valve 101. A similar command is issued, and a command to form a flow path from one of the inflow path 93 and the merge path 97 to the other is issued to the fourth path forming valve 111.

  Thus, after the flow path is formed in s220, the controller 71 causes the water flow valve 53 to open the water flow path 51 to start water flow to the formed flow path (s230). In s220, a flow path is formed from the downstream side of the circulation path 31 to the inflow path 93 connected to the drain tank 91. Therefore, by starting the water flow in this s230, the downstream in the circulation path 31 is formed. Hot water flows not only on the side but also on the drain tank 91 side through the inflow path 93 and the merging path 97 (FIG. 4B).

It will be in a standby state until it becomes the timing which should complete | finish the water flow started in said s230 (s240: NO).
In the present embodiment, it is determined that it is time to end the water flow when the amount of cleaning water based on the output result from the water level sensor 99 has reached a predetermined value or more. This “predetermined value” is determined in advance as the amount of hot water that is assumed to flow into the drain tank 91 when the circulation path 31, the merging path 97, and the inflow path 93 are sufficiently washed. The determination that this timing has been reached may be made based not only on the amount of cleaning water but also on the fact that a predetermined time has elapsed, for example.

  In this s240, when it is determined that it is time to end the water flow (s240: YES), the controller 71 is formed in the above-described s220 by causing the water flow valve 53 to close the water flow path 51. Water flow to the distribution channel is terminated (s250).

In this way, when the water flow is completed, the command to each valve body is returned to the initial state (s310), the process returns to s110, and s110 to s310 are repeated thereafter.
(1-3) Action and Effect With the water heater in the above embodiment, the circulation pump 33 is operated in a state in which a circulation path extending from the discharge path 95 to the downstream side of the circulation path 31 through the merging path 97 is formed. As a result, the drain stored in the drain tank 91 can be circulated from the drain tank 91 to the circulation path 31 via the merge path 97 and discharged from the downstream side of the circulation path 31 (see FIG. 4A). ).

  And from the water flow path 51 in the state which reached the circulation path 31 from the inflow path 93 via the confluence | merging path | route 97 and formed the flow path which continues to the downstream (circulation pump 31, heat exchanger 37 side) in the circulation path 31. Thus, hot water can be circulated from the circulation path 31 to the drain tank 91 through the merge path 97. In this way, a part of the hot water flowing from the water passage 51 is directed to the downstream side of the circulation path 31, and the other is directed from the upstream side of the circulation path 31 to the drain tank 91 via the junction path 97 and the inflow path 93. Therefore (see FIG. 4B), the hot water can properly clean the paths through which the drain stored in the drain tank 91 in the circulation path 31 passes. Further, when the cleaning of the path is completed, the inside of the merging path 97 directly connected to the circulation path 31 can be filled with clean hot water. For this reason, from the state in which the circulation path from the downstream side of the merging path 97 and the circulation path 31 to the other is formed, the circulation path from the upstream side and the downstream side of the circulation path 31 to the other is formed. It is possible to reliably prevent the drain in the drain reservoir 9 from being mixed into the circulation path during the transition to the state.

  Moreover, in the said embodiment, discharge | emission of drain can be started at the timing when the quantity of the drain stored by the drain tank 91 reached the upper limit ("YES" in s110 in FIG. 3).

  Further, in the above embodiment, since the cleaning of the path is started at a timing when the amount of drain stored in the drain tank 91 becomes a lower limit value greater than 0 (“YES” in s140 in FIG. 3), the merging path The path cleaning can be started in a state where the drain (or hot water) of the amount corresponding to the lower limit value is left in the partial path reaching the circulation path 31 through 97.

  Therefore, as in the above embodiment, if the lower limit value is set to a value sufficient to keep the drain filled in the circulation path 31 up to the path where the circulation pump 33 is provided, the circulation pump is again used. When actuating 33, it is possible to prevent problems (so-called air biting and abnormal noise) in which proper circulation of hot water by the circulation pump 33 is hindered by the air in the circulation path 31.

  In addition, when the sensor 99 breaks down, there is no possibility that air will mix in the circulation path 31 (s140: Yes). However, even if air is mixed in, the hot air supplied from the water passage 51 when the route is washed causes the air to pass through the downstream side of the circulation passage 31 through a discharge port (not shown) or through the junction route 97. It is discharged to the outside through the drain tank 91, and the periphery of the circulation pump 33 in the circulation path 31 can be filled with hot water.

  Further, in the above-described embodiment, the functions of the first path forming valve 101 and the second path forming valve 103 are used to form a circulation path via the merging path 97 between the inflow path 93 and the discharge path 95 and the circulation path 31. Thus, drain discharge including path cleaning can be realized.

  In particular, the second path forming valve 103 provided in the discharge path 95 prevents the flow of hot water from the merging path 97 to the drain tank. Can be prevented.

Further, in the above embodiment, the third path forming valve 105 provided in the inflow path 93 prevents the drain from flowing from the drain tank 91 toward the merging path 97, so that the inflow path 93 is not controlled to open and close. In addition, unintended backflow of drain can be prevented.
(1-4) Modifications Although the first embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and various forms are possible as long as they belong to the technical scope of the present invention. It goes without saying that it can be taken.

  For example, in the above-described embodiment, since a certain amount of hot water is stored in the drain tank 91 by washing the path for circulating hot water from the circulation path 31 to the drain tank 91 via the confluence path 97, this It is good also as discharging hot water.

Specifically, as shown in FIG. 5, after s220 to s250 are performed, s120 to s150 may be performed again.
If comprised in this way, the capacity | capacitance which can store the drainage which can be generated after that can be ensured by discharging | emitting the hot water stored by the drain tank 91 by the path | route washing | cleaning performed later.

  In this configuration, after the hot water stored in the drain tank is discharged by the cleaning of the route, the cleaning of the route may be performed again, and a cycle including the hot water discharge and the cleaning of the route is performed. By repeating the operation time a plurality of times while gradually shortening the operation time, the amount of hot water finally stored in the drain tank 91 may be less than a certain level, and a drain storage area may be secured.

Moreover, in the said embodiment, the structure in which the inflow path 93 was connected to the upper part of the drain tank 91 was illustrated. However, the inflow path 93 may be connected to the bottom of the drain tank 91. In this case, as shown in FIGS. 6 (a) and 6 (b), instead of the third path forming valves 105 and 109, a partial section of the inflow path 93 is formed with a throttle portion 93a having a smaller diameter than the others. Then, since the same effect can be obtained, reducing a valve body, it is suitable.
(2) Second Embodiment (2-1) Overall Configuration Next, a water heater according to the second embodiment will be described.

  Similar to the above embodiment, the water heater according to the second embodiment includes a hot water supply unit 1, a heat retaining unit 3, a connection unit 5, a control unit 7, and a drain storage unit 9, and is partially configured. However, only this difference will be described in detail.

Further, as shown in FIG. 7, the drain reservoir 9 has an end opening in the inflow passage 93 connected to a position away from the bottom surface inside the drain tank 91 by a predetermined height.
The path forming section 100 in the drain storage section 9 is a distribution path from the discharge path 95 to the downstream side of the circulation path 31 through the communication section and a distribution path from the downstream side of the circulation path 31 to the inflow path 93 through the communication section. As shown in FIG. 7A, the path can be formed by the first path forming valve 101 and the second path forming valve 103.

  Specifically, the first path formation valve 101 is the same valve body (three-way valve) as in the above embodiment, and the second path formation valve 103 is from the merging path 97 to the drain tank 91 in the discharge path 95. It is a valve body (check valve) that prevents the flowing hot water from flowing.

In addition to the configuration described above, for example, as shown in FIG. 7B, the path forming unit 100 is provided with an open / close valve body 107 that closes and opens the discharge path 95 as a second path forming valve. It is good also as a structure. In this configuration, the second path forming valve 107 may be closed as an initial state.
(2-2) Drain Discharge Control In the drain discharge control according to the present embodiment, after s110 to s130 are performed, the standby state is reached until the hot water circulation end timing is reached in s140 (s140). In this case, the water flow switch 35 is turned off, and the water flow in the circulation path 31 is reduced to the extent that proper circulation of hot water by the circulation pump 33 is hindered by the air in the circulation path 31 (so-called air biting). It is determined that the end timing of the hot water distribution has come. That is, in this embodiment, the water level sensor 99 that detects that the drain amount has reached the lower limit value is not required (see the broken line portion in FIG. 7).

  Here, when the circulation pump 33 has a function of automatically stopping the operation by detecting the air bite, the operation is automatically stopped by this function, so that the end timing of the hot water circulation is reached. Can be determined. In this case, the subsequent s150 is not performed.

  When it is determined in s140 that it is time to end the circulation of the hot water (s140: YES), the controller 71 stops the operation of the circulation pump 33 (s150) and then cleans the circulation path. Is formed (s220). Here, in order to set the flow path from the downstream side of the circulation path 31 to the inflow path 93 in the path forming section 100, a command is issued to the path forming section 100.

  In addition, the command with respect to the path | route formation part 100 changes with the structure of the path | route formation part 100 similarly to the said embodiment. For example, when the second path forming valve 103 is configured by a check valve (FIG. 7A), the downstream side of the merging path 97 and the circulation path 31 from one side to the other side with respect to the first path forming valve 101. Only directives that should form a distribution channel are made.

  When the second path forming valve 107 is configured by an open / close valve body (FIG. 7B), the same command as described above is given to the first path forming valve 101, and the second path A command is issued so that the forming valve 107 is closed.

In this way, after the distribution route is formed in s220, s230 to s310 are performed as in the above embodiment, and thereafter s110 to s310 are repeated.
(2-3) Action and Effect In the above embodiment, since the end opening in the inflow passage 93 is connected to a position away from the bottom surface inside the drain tank 91 by a predetermined height, the drain stored in the drain tank 91 is stored. When the drain amount decreases until the liquid level is located below the opening end, the air inside the drain tank 91 is directed from the opening end toward the merging path 97 via the inflow passage 93. At this time, since the circulation pump 33 is operating, as a result of the air that has reached the merging path 97 reaching the water flow switch 35, the air flow by the air is detected by the water flow switch 35 and the circulation pump 33 is stopped. Path cleaning can be initiated.

  Note that air mixed in the circulation path is excluded from the circulation path 31 by hot water supplied from the water passage 51 when the path is washed. Therefore, the air mixed in the circulation path 31 does not adversely affect the driving of the circulation pump 33.

For this reason, in this embodiment, the amount of drain stored in the drain tank 91 is determined by setting the connection position of the end opening in the inflow passage 93 to a position corresponding to the amount of drain to stop the circulation pump 33. At the timing when becomes the desired lower limit value, air engagement is intentionally caused to stop the circulation pump 33 and start cleaning of the path.
(2-4) Modifications The second embodiment of the present invention has been described above. However, the present invention is not limited to the above-described embodiment, and various forms are possible as long as they belong to the technical scope of the present invention. It goes without saying that it can be taken.

  For example, in the above-described embodiment, the configuration in which the end opening in the inflow passage 93 is connected to a position away from the bottom surface in the drain tank 91 by a predetermined height is illustrated. However, the inflow path 93 is not limited to the connected state as in this example, and for example, as shown in FIGS. 8A and 8B, the inflow path 93 penetrates into the drain tank 91, and An opening that communicates the inside and the outside (here, the opening end face) may be formed at least a predetermined height away from the bottom surface inside the drain tank 91.

  Also in this configuration, since the opening that connects the inside of the drain tank 91 and the inflow passage 93 is formed at a position away from the bottom surface inside the drain tank 91, the liquid of the drain stored in the drain tank 91 is formed. When the drain amount decreases until the surface is positioned below the opening, the air inside the drain tank 91 is directed from this opening to the merging path 97 through the inflow path. Thereby, the air biting by the air can be detected by the water flow switch 35 and the circulation pump 33 can be stopped. That is, by setting the position of the opening in the inflow passage 93 to a position corresponding to the amount of drain to stop the circulation pump 33, the circulation pump at the timing when the amount of drain stored in the drain tank 91 becomes a desired lower limit value. 33 can be stopped and cleaning of the path can be started.

Therefore, an electrode or the like for detecting the lower limit value of the drain becomes unnecessary, and the apparatus configuration can be simplified. Also, drain discharge is started not depending on the drain storage amount, but at a predetermined time instead of the drain storage amount, when a predetermined time has elapsed, user operation, etc. This eliminates the need for a configuration for detecting the upper limit value, thereby further simplifying the device configuration.
(3) Other Embodiments Although the embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and can take various forms as long as it belongs to the technical scope of the present invention. Needless to say, you get.

  For example, in each of the above-described embodiments, the configuration in which the inflow path 93 and the discharge path 95 are communicated with the circulation path 31 via the merging path 97 is illustrated. However, the inflow path 93 and the discharge path 95 may be configured to be connected to the circulation path 31 without passing through the merging path 97.

  In this case, for example, as shown in FIG. 9A, a first path forming valve in the circulation path 31 is provided by a fifth path forming valve 113 which is a valve body (that is, a three-way valve) similar to the first path forming valve 101. It is good to comprise so that drain discharge control may be performed as follows, after letting inflow way 93 communicate between 101 and bathtub 210.

  In this drain discharge control, first, when forming a flow path to discharge drain at s120, the first path forming valve 101 reaches from the downstream side of the discharge path 95 and the circulation path 31 to the other side. A command to form a flow path is issued, and a command to form a flow path from one of the upstream side and the downstream side of the circulation path 31 to the other side is issued to the fifth path forming valve 113.

  Then, in forming a flow path to clean the path in s220, a command to form a flow path from one of the upstream side and the downstream side in the circulation path 31 to the other side with respect to the first path forming valve 101. The fifth path forming valve 113 is commanded to form a flow path from one of the downstream sides of the inflow path 93 and the circulation path 31 to the other.

  Moreover, in each said embodiment, the structure in which the inflow path 93 and the discharge path 95 were each connected to the drain tank 91 as another path | route was illustrated. However, the inflow path 93 and the discharge path 95 may be configured so that a part of the sections is a common path.

  As a specific example, as shown in FIGS. 9B and 9C, it is considered that the section on the side connected to the drain tank 91 in the inflow path 93 is configured as a path common to the discharge path 95. In this case, if the third passage forming valves 105 and 109 are replaced with a partial section of the inflow passage 93 formed with a narrowed portion 93a having a smaller diameter than others, the same effect can be obtained while reducing the valve body. Is preferable.

  Moreover, in each said embodiment, although the drain tank 91 of the drain storage part 9 collected the drain which generate | occur | produces from the auxiliary heat exchanger 13 in the hot water supply part 1, and was stored by the drain tank 91, the heat retention part was illustrated. 3, the one that collects latent heat is adopted as the heat exchanger 37 in the heat exchanger 37, and the drain generated from the heat exchanger 37 on the heat retaining unit 3 side is also collected and stored in the drain tank 91. May be.

  Moreover, in each said embodiment, although the drain storage part 9 and the drain discharge | emission control (the program) illustrated the structure previously mounted in the water heater, these were mounted in the separate apparatus (this invention) The water heater in the present invention may be configured by connecting a drain discharge device) to the water heater.

  Moreover, in each said embodiment, although the drain (or hot water) which distribute | circulated the circulation path 31 was illustrated by the waste_water | drain switching valve 41 provided in the circulation path 31 was illustrated, You may make it discharge from the drain outlet provided in the bathtub 210, without performing instruction | command.

In each of the above embodiments, the hot water heater in which the drain storage unit 9 is incorporated in advance has been described. However, the drain storage unit is retrofitted to an existing water heater, and the drain storage unit is stored in the controller of the hot water heater or a separate controller. Needless to say, even if the control program for each part is incorporated, the same operational effects as those of the above embodiments can be obtained.
(4) Correspondence with this invention In embodiment described above, the drain storage part 9 and the controller 71 are the drain discharge apparatuses in this invention.

  Further, s110 and the water level sensor 99 in the drain discharge control are the drain detection means in the present invention, s120 to s150 in the drain discharge control are the discharge control means in the present invention, and s220 to s250 are the cleaning control means in the present invention. is there.

  DESCRIPTION OF SYMBOLS 1 ... Hot water supply part, 3 ... Thermal insulation part, 5 ... Connection part, 7 ... Control part, 9 ... Drain storage part, 11 ... Hot water supply path, 13 ... Sub heat exchanger, 15 ... Main heat exchanger, 17 ... Gas burner, 19 ... Neutralizer, 25 ... Strainer, 27 ... Water quantity sensor, 29 ... Water quantity control valve, 31 ... Circulation path, 33 ... Circulation pump, 35 ... Water flow switch, 37 ... Heat exchanger, 39 ... Gas burner, 41 ... Drain switch valve , 51 ... Water flow path, 53 ... Water flow valve, 71 ... Controller, 73 ... Kitchen remote control, 75 ... Bathroom remote control, 91 ... Drain tank, 93 ... Inflow path, 93a ... Throttle part, 95 ... Discharge path, 97 ... Merge path , 99 ... Water level sensor, 100 ... Path formation unit, 101 ... First path formation valve, 103 ... Second path formation valve, 105 ... Third path formation valve, 107 ... Second path formation valve, 109 ... Third path formation Valve 111 ... fourth path forming valve 113 ... first Path formation valve, 210 ... bath, 220 ... water tap, A ... share interval.

Claims (9)

It is a path for supplying water supplied from the outside, and a hot water supply path provided with a heat exchanger for collecting latent heat in a part of the path;
A water passage that allows hot water supplied from the hot water supply passage to pass through the water supply valve to the bathtub side;
A path that circulates hot water stored in the bathtub with a circulation pump and returns the hot water to the bathtub. A circulation path serving as a shared section leading to the bathtub;
A drain tank for storing drain generated from the heat exchanger;
A drain discharger provided in a water heater comprising:
By connecting each of the inflow path for flowing hot water into the drain tank and the discharge path for discharging drain from the drain tank to the circulation path, and switching the flow direction of the hot water in the communication section, A route forming unit that forms a distribution route through the communication unit;
The circulation pump is closed in the state where the flow path is closed by the water flow valve and a flow path from the discharge path to the downstream side of the circulation path through the communication part is formed in the path formation part. Discharge control means for circulating the drain stored in the drain tank from the drain tank to the circulation path through the communication portion by operating the drain tank;
In the state where the flow path from the downstream side of the circulation path to the inflow path in the communication part is formed in the path formation part, the water flow valve opens the water flow path to perform water flow. Washing control means for circulating hot water from the circulation path to the drain tank through the communication section, and flowing hot water toward the downstream side of the circulation path. Discharging device. A drain detecting means for detecting the amount of drain stored in the drain tank,
The discharge control means starts the flow of drain from the drain tank to the circulation path when the amount of drain detected by the drain detection means reaches a predetermined upper limit. The drainage device described in 1. The discharge control means causes the drain to flow from the drain tank to the circulation path until the amount of drain stored in the drain tank reaches a lower limit defined as a value larger than 0. The drain discharge device according to claim 1 or 2. The end opening in the inflow passage is connected to the drain tank at a position spaced apart from the bottom surface in the drain tank by a predetermined height. Drain discharge device. The inflow path penetrates to the inside of the drain tank, and an opening that communicates the inflow path with the inside and outside is formed at a position at least a predetermined height away from the bottom surface inside the drain tank. The drain discharge device according to any one of claims 1 to 3. The discharge control means, after the hot water flow by the cleaning control means, closes the water flow path by the water flow valve, and flows from the drain tank to the downstream side of the circulation path through the communication portion The hot water stored in the drain tank is circulated from the drain tank to the circulation path through the communication part by operating the circulation pump in a state where the path is formed in the path forming part. The drain discharge device according to any one of claims 1 to 5, wherein The communication part between each of the inflow path and the discharge path and the circulation path has a merging path that joins the inflow path and the discharge path to reach the circulation path,
The path forming unit includes at least a first path forming valve and a second path forming valve,
The first path forming valve has a communication portion between the circulation path and the merging path at least from one of the upstream side and the downstream side in the circulation path to the other, the merging path and the circulation path. It is a valve body that switches to one of the flow paths from one of the downstream sides to the other,
The second path formation valve is a valve body that blocks the flow of hot water from the merging path to the drain tank in the discharge path,
In the state in which the water flow path is closed by the water flow valve, the discharge control means is configured such that the communication path between the circulation path and the merge path is set in the merge path and the circulation path by the first path formation valve. After switching the flow path from one to the other on the downstream side, by operating the circulation pump, from the drain tank to the circulation path via the discharge path and the communication portion, the drain tank Distribute the stored drain,
The cleaning control means circulates hot water from the circulation path to the drain tank through the communication section and the inflow path by opening the water passage with the water passage valve and performing water passage. The drain discharge device according to any one of claims 1 to 6, wherein The path forming unit includes at least the first path forming valve, the second path forming valve, and a third path forming valve,
The drain discharge device according to claim 7, wherein the third path formation valve is a valve body that blocks the flow of hot water from the drain tank toward the merge path in the inflow path. It is a path for supplying water supplied from the outside, and a hot water supply path provided with a heat exchanger for collecting latent heat in a part of the path;
A water passage that allows hot water supplied from the hot water supply passage to pass through the water supply valve to the bathtub side;
A path that circulates hot water stored in the bathtub with a circulation pump and returns the hot water to the bathtub. A circulation path serving as a shared section leading to the bathtub;
A drain tank for storing drain generated from the exchanger;
A drain discharge device according to any one of claims 1 to 8,
A water heater characterized by comprising.