JP5407838B2 - Hot water storage water heater - Google Patents

Description

  The present invention relates to a hot water storage type water heater.

  Wide range of hot water storage water heaters with a chasing function that allows hot water in the hot water storage tank and bath water in the bathtub to be directed to the heat exchanger for chasing to exchange heat. It is used. In this device, dirt such as sebum and keratin washed away from the human body in the bath water circulates in the tracking circulation line and inevitably adheres to the inner surface of the piping and the heating heat exchanger. To do. When the dirt is accumulated to a certain extent, the dirt is recirculated to the bathtub during the chasing operation to contaminate the bathtub and bath water, or the heat exchanging efficiency of the chasing heat exchanger is reduced.

  To deal with the above problems, the microbubbles are automatically generated in the pipes using an ejector, which is a fine bubble generator, and the cleaning operation is performed to keep the purging pipes and the heat exchanger clean. A water heater with a chasing function that is unnecessary has been invented (see Patent Document 1).

JP 2009-186092 A

  However, in the conventional apparatus, the fine bubbles are continuously supplied into the pipe connected to the hot water supply device with the tracking function. Therefore, the cleaning effect is gradually reduced. Particularly in stainless steel heat exchangers, sebum dirt is likely to adhere due to the material, and dirt is difficult to remove. For this reason, it was necessary to set a long cleaning time and a large amount of water used in order to ensure a sufficient cleaning effect during the cleaning operation. This has led to an increase in the amount of power and water used to operate the hot water heater with a chasing function.

  Also, by adding a small amount of additives such as surfactants to the water, the properties of the fine bubbles generated in the ejector, which is a fine bubble generator, are stabilized in the liquid, and the fine bubbles are unified. Although the invention which suppresses is made conventionally, in this case, since a user needs to add an additive, there exists a problem that it cannot wash | clean fully automatically.

  The present invention has been made to solve the above-described problems, and can surely suppress the coalescence of fine bubbles for cleaning without bothering the user's hand, resulting in a cleaning effect. It is an object of the present invention to provide a hot water storage type water heater with a tracking function that can be improved.

The hot water storage type hot water heater according to the present invention is a hot water storage type hot water supply capable of chasing the bath water in the bathtub by exchanging heat between the hot water stored in the hot water storage tank and the bath water in the bathtub with a heat exchanger. A circulation line arranged so as to return from the bathtub to the bathtub through the heat exchanger, a bath-side water supply pump for circulating the bath water in the circulation line, and in the middle of the circulation line. A circulation ejector disposed upstream of the heat exchanger and capable of generating fine bubbles having an average diameter of 10 μm to 100 μm in the bath water for cleaning the inside of the heat exchanger and the circulation pipe, and circulation The inside of the heat exchanger and the circulation pipeline is circulated by circulating the ejector air solenoid valve for opening and closing the air intake connected to the ejector for air and the bath water containing fine bubbles generated by the ejector for circulation. When doing water on the bath side Control means for pulsatingly operating the bath-side water pump so that the amount of microbubbles periodically changes by alternately repeating the high-rotation state and the low-rotation state of the pump. .

  According to the present invention, it is possible to reliably suppress coalescence of fine bubbles for cleaning the inside of the heat exchanger for tracking and the circulation pipe line, so that the cleaning effect can be improved. Further, there is no need to bother the user to add the additive.

It is a circuit block diagram of the heat pump hot-water supply apparatus as Embodiment 1 of the hot water storage type water heater of this invention. It is a figure which shows the motion of the bubble at the time of operating a bath side water pump continuously and inject | pouring air into water continuously. It is a figure which shows the motion of the bubble at the time of controlling so that a bath side water pump may be operated pulsatingly and injecting air into water pulsatingly. It is the figure which expanded the principal part of FIG. It is a control block diagram of the fine bubble generator with which the heat pump hot-water supply apparatus of Embodiment 1 is provided. It is a flowchart of the automatic washing | cleaning in Embodiment 1 of this invention. It is a flowchart of the washing | cleaning in Embodiment 2 of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. In addition, the same code | symbol is attached | subjected to the element which is common in each figure, and the overlapping description is abbreviate | omitted.

Embodiment 1 FIG.
FIG. 1 is a circuit configuration diagram of a heat pump hot water supply apparatus as Embodiment 1 of a hot water storage type hot water supply apparatus of the present invention. The heat pump water heater shown in FIG. 1 includes a heat pump unit 1 and a tank unit 2. The heat pump unit 1 is configured by connecting a compressor 3, a radiator 4, an expansion valve 5, and an evaporator 6 in order by a pipe 7, and is housed in a heat pump unit case 8. The heat pump unit 1 preferably uses carbon dioxide, which is a natural refrigerant, as a refrigerant, and operates on a high pressure side in a state exceeding the critical pressure. The tank unit 2 includes a hot water storage tank 10 and a plate heat exchanger 11 for bathing in a tank unit case 9. As the hot water storage tank 10, a stacked hot water storage tank that is separated and stored in an upper layer of high-temperature water and a lower layer of low-temperature water is used. As the plate-type heat exchanger 11, a stack of a plurality of heat transfer plates is used in a vertical position.

  The plate heat exchanger 11 is a water-water heat exchanger in which a water flow is opposed to each other, and a tank side inlet 111 and a bath side outlet 114 are provided in the upper part, and a tank side outlet 112 and a bath side inlet are provided in the lower part. 113 is provided. Hot water supplied from the upper tank side inlet 111 is discharged from the lower tank side outlet 112. Bath water supplied from the lower bath-side inlet 113 is discharged from the upper bath-side outlet 114.

  The hot water storage tank 10 is provided with a hot water outlet 101 and a hot water inlet 103 in the upper part, and a water inlet 102 and a water outlet 104 in the lower part. Hot water is supplied to the tank side inlet 111 at the upper part of the plate heat exchanger 11 through the pipe 12 from the hot water outlet 101 at the upper part of the hot water storage tank 10, and after the heat exchange at the plate heat exchanger 11, It is discharged from the tank side outlet 112. The discharged water is returned to the hot water storage tank 10 from the water inlet 102 at the lower part of the hot water storage tank 10 through the pipe 14 by the tank side water pump 13. A primary water supply circuit of the plate heat exchanger 11 is formed by the pipe 12, the plate heat exchanger 11, the tank side water pump 13 and the pipe 14.

  On the other hand, hot water from the bathtub 15 is supplied to the bath-side inlet 113 at the lower part of the plate heat exchanger 11 through the bathtub adapter 34 by the bath-side water pump 16 from the bathtub return pipe 17 (circulation pipe). It becomes the warm water which was heat-exchanged with the type | formula heat exchanger 11, and was heated. Thereafter, the hot water discharged from the upper bath-side outlet 114 is returned to the bathtub 15 through the bathtub outlet pipe 18 (circulation pipe line) and the bathtub adapter 34. A secondary side water supply circuit of the plate type heat exchanger 11 is formed by the bathtub return pipe 17, the bath side water supply pump 16, the plate type heat exchanger 11 and the bathtub outlet pipe 18.

  In the middle of the bathtub return pipe 17, a water level detecting means (for example, a water level sensor 39) for detecting the bathtub water level and a water flow presence / absence detecting means (for example, a flow switch 47) for checking the presence or absence of a water flow when water is supplied by the bath-side water pump 16. ) And a circulation ejector 28 for generating fine bubbles. In the air intake portion of the circulation ejector 28, a circulation ejector air check valve 30 for preventing backflow and a circulation ejector air electromagnetic valve 29 for controlling the introduction of air into the ejector are installed. When the circulating ejector air solenoid valve 29 is opened after the circulating ejector air solenoid valve 29 provided at the ejector air inlet port is closed, the inlet port is always at a negative pressure and air is sucked in. become. By observing this operating procedure, the circulation ejector air check valve 30 is not necessary, but it is desirable to arrange the circulation ejector air check valve 30 when an erroneous operation is considered. Fine air bubbles are generated by passing the sucked air through the circulation ejector 28, and the fine air bubbles are caused to flow to the bathtub return pipe 17, the plate heat exchanger 11 and the bathtub outlet pipe 18 on the downstream side. Can be washed.

  Water from the water outlet 104 at the lower part of the hot water storage tank 10 is supplied to the radiator 4 of the heat pump unit 1 through the pipe 20 by the boiling water pump 19 and heated by the radiator 4. The hot water storage tank 10 is returned to the hot water storage tank 10 through the hot water inlet 103 at the top. The boiling water pump 19, the pipe 20, the radiator 4 and the pipe 21 constitute a hot water storage circuit.

  The pressure reducing valve 25 reduces the city water supplied from the water source to a predetermined pressure and supplies the hot water storage tank 10 with water. The hot water mixing valve 24 creates hot water having a desired temperature set by the remote controller 46 by mixing hot water from the hot water storage tank 10 with water from city water, and supplies the hot water to the hot water supply port 27. The bath hot water mixing valve 23 creates hot water having a desired temperature set by the remote controller 46 by mixing hot water from the hot water storage tank 10 with water from city water. The produced hot water is injected into the bathtub 15 through the water injection pipe 26, the bathtub return pipe 17, and the bathtub outlet pipe 18.

  In the middle of the water injection pipe 26, a water injection pipe flow rate adjustment device (for example, a water injection electromagnetic valve 44), a flow rate detection device (for example, a flow rate sensor 40), and a water injection ejector 31 for generating fine bubbles are installed. The air intake portion of the water injection ejector 31 is provided with a water injection ejector air check valve 33 for preventing backflow and a water injection ejector air solenoid valve 32 for controlling the introduction of air into the ejector. A state in which the inlet is always negative pressure and the air is sucked in by opening the water injector with a water injection after the hot water is flowed in a state where the ejector air solenoid valve 32 for water injection provided at the ejector air inlet is closed. become. By observing this operation procedure, the water injection ejector air check valve 33 becomes unnecessary, but it is desirable to dispose the water injection ejector check valve 33 in consideration of erroneous operation. By passing the sucked air through the water injection ejector 31, fine bubbles are generated, and the fine bubbles are allowed to flow through the bathtub return pipe 17 and the bathtub return pipe 18, thereby cleaning the inside.

  It is desirable that the fine bubbles generated by the circulation ejector 28 and the water injection ejector 31 have an average diameter of about 10 μm to 100 μm. Thereby, a particularly excellent cleaning effect can be obtained.

  FIG. 5 is a control block diagram of the fine bubble generating device provided in the heat pump hot water supply apparatus of the first embodiment. As shown in FIG. 5, the control unit 45 receives signals from the flow sensor 40, the flow switch 47, the water level sensor 39 and the remote controller 46, and receives the hot water mixing valve 24, the bath hot water mixing valve 23, and the water injection electromagnetic The valve 44, the bath-side water pump 16, the boiling water pump 19, the tank-side water pump 13, the circulation ejector air solenoid valve 29, and the water injection ejector air solenoid valve 32 are controlled. In the control system of the heat pump water heater, when the user operates the remote controller 46, a signal is transmitted to the control unit 45, and the control unit 45 controls each operation by the signal. The remote control 46 is provided with a cleaning function selection button 461, a display device 462 made up of, for example, a liquid crystal display device, and an audio generator 463.

  Next, operation | movement of this heat pump hot-water supply apparatus is demonstrated. In FIG. 1, the heat pump unit 1 is operated by a hot water storage operation signal, and the refrigerant is compressed by the compressor 3 to become high temperature and high pressure, cooled by the radiator 4, depressurized by the expansion valve 5, and absorbs heat from the atmosphere by the evaporator 6. And return to the compressor 3. On the other hand, water is supplied to the radiator 4 from the water outlet port 104 at the lower part of the hot water storage tank 10 through the piping 20 by the boiling water pump 19, and the supplied water is heated by the radiator 4. Then, the hot water heated to a high temperature flows from the hot water inlet 103 at the top of the hot water storage tank 10. Accordingly, the hot water is sequentially stored from the upper part of the hot water storage tank 10.

  When performing bath pursuit, in the tank side water supply circuit of the tank unit 2, the hot water in the upper part of the hot water storage tank 10 is discharged from the hot water outlet 101 and the upper part of the plate heat exchanger 11 through the pipe 12. From the tank side inlet 111. The supplied high-temperature water undergoes heat exchange while passing through the plate heat exchanger 11 to become a low temperature, is discharged from the lower tank side outlet 112, and is supplied from the water inlet 102 through the pipe 13 into the hot water storage tank 10. Flows into the bottom. This water supply operation is performed by the tank side water supply pump 13. As described above, the water stored in the lower part of the hot water storage tank 10 is supplied to the radiator 4 of the heat pump unit 1 to exchange heat.

  In the bath-side water supply circuit, water from the bathtub 15 is supplied from the lower bath-side inlet 113 to the plate heat exchanger 11 via the bathtub return pipe 17 and heated while passing through the plate heat exchanger 11. Then, it returns to the bathtub 15 through the bathtub outlet pipe 18 from the upper bath-side outlet 114. This water supply operation is performed by the bath-side water supply pump 16.

  In this way, in the plate heat exchanger 11, when the hot water of the tank-side water supply circuit is supplied from the upper part and the low-temperature water of the bath-side water supply circuit is supplied from the lower part, the heat is easily transferred upward, so the plate-type heat exchange The amount of heat exchange can be increased by setting the upper portion of the vessel 11 at a higher temperature. Moreover, the lower part of the plate type heat exchanger 11 can be made into a lower temperature state, and the hot water returned to the hot water storage tank 10 can be made into a low temperature. As a result, even if the amount of water used for hot water supply is small, the city water is hardly supplied to the bottom of the hot water storage tank 10, and the bath is chased with a considerable amount of heat accumulated in the hot water storage tank 10, Since heat can be sufficiently exchanged by the plate heat exchanger 11 having a high heat exchange capability, the lower part of the hot water storage tank 10 can be kept at a low temperature.

  During the bath chasing operation, dirt substances such as sebum, organic matter and dust mixed in the bathtub 15 are circulated in the plate heat exchanger 11, the bathtub return pipe 17 and the bathtub outlet pipe 18 by circulation of the bath water from the bathtub 15. It adheres to the inner wall and causes a decrease in heat exchange efficiency and clogging of the bathtub return pipe 17 and the bathtub return pipe 18. In particular, in the plate heat exchanger 11 in which the interlayer is narrowed to about 1 mm in order to reduce the size of the bath water heater, dirt easily adheres between the layers. For this reason, it is desired to enhance the cleaning effect when the plate heat exchanger 11, the bathtub return pipe 17 and the bathtub return pipe 18 are cleaned using fine bubbles.

  In response to such demands, the present inventors have conducted extensive research and, as a result, periodically (pulsating) the amount of fine bubbles generated to be supplied to the plate heat exchanger 11, the bathtub return pipe 17 and the bathtub return pipe 18. It was found that the cleaning effect can be enhanced by changing to). Below, the concrete effect at the time of controlling the bath side water pump 16 pulsatingly is demonstrated as a representative. FIG. 2 is a diagram illustrating the movement of bubbles when the bath-side water pump 16 is continuously operated and air is continuously injected into water. FIG. 3 is a diagram showing the movement of bubbles when the bath-side water pump 16 is controlled to operate in a pulsating manner, and air is injected into the water in a pulsating manner.

  As shown in FIG. 2, when the bath-side water pump 16 is continuously operated, the intake port of the circulation ejector 28 always has a negative pressure during the continuous operation and is in an intake state. The fine bubbles 60 generated by passing through the circulation ejector 28 are first dispersed in the direction of water flow, but are gradually united. Large bubbles 61 accumulate in the upper end portions of the plate heat exchanger 11, the bathtub return pipe 17, and the bathtub return pipe 18, and eventually a gas layer 62 is generated and cleaning with the fine bubbles 60 becomes impossible. In addition, since the coalescence opportunity of the fine bubble 60 increases, so that the piping construction conditions of the bathtub return piping 17 and the bathtub going piping 18 are long piping, it becomes a bad condition. In such a state, since the cleaning effect is lowered, if this state continues for a long period of time, dirt accumulates on the inner wall of the bathtub return pipe 17 and the bathtub outlet pipe 18 and the plate heat exchanger 11, and contamination of the bathtub 15 There is a possibility that problems such as a decrease in flow rate and a decrease in heat exchange efficiency of the plate heat exchanger 11 may occur. Therefore, it is possible to suppress the coalescence of the fine bubbles 60 and reduce the ratio of the large bubbles 61. The cleanliness in the vicinity of the end joining the inner wall of the bathtub return pipe 17 and the bathtub return pipe 18, the plate heat exchanger 11, and the bathtub 15 is achieved. It becomes indispensable to maintain.

  On the other hand, as shown in FIG. 3, when the bath-side water pump 16 is operated in a pulsating manner, the suction port of the circulation ejector 28 has a negative pressure only while the bath-side water pump 16 is operating at a high speed. Thus, the intake state is established. The fine bubbles 60 generated by passing through the circulation ejector 28 are separated into a portion where the bubbles are present and a portion where the bubbles are not present by the pulsating operation of the bath-side water supply pump 16 and are uniformly distributed later. Therefore, bubbles are not united even inside the plate heat exchanger 11 or at the ends of the bathtub return pipe 17 and the bathtub return pipe 18, and the state of the fine bubbles 60 can be maintained and cleaning can be performed with a high cleaning effect. it can.

  According to the experiments conducted by the present inventors, the pulsation operation time of the bath-side water pump 16 that can actually obtain a high cleaning effect is obtained by drawing the bath water from the bathtub 15 by the bath-side water pump 16 and circulating the ejector. The bath-side water supply pump 16 is operated for 2.5 seconds during circulation cleaning in which the downstream-side bathtub return pipe 17, the plate heat exchanger 11 and the bathtub outlet pipe 18 are cleaned by the fine bubbles 60 generated through 28. After flowing the water containing the fine bubbles 60, the operation of stopping the bath-side water supply pump 16 for 1.5 seconds was repeated. Further, the rotation speed of the bath-side water pump at this time is controlled to be a maximum rotation speed of 6300 rpm for 2.5 seconds in a high rotation state. The subsequent 1.5 seconds may be controlled to be 0 rpm for complete stop, or may be controlled to be about 1000 rpm without being completely stopped. Thereby, compared with the time of continuous operation | movement, the contaminant removal rate was able to be improved about 25%. Thus, in the pulsation operation of the bath-side water pump 16 during cleaning, a particularly excellent cleaning effect was obtained by making the duration of the high rotation state longer than the duration of the low rotation state.

  In addition, after the circulating cleaning, the water injection electromagnetic valve 44 is opened to flow water, and the water return cleaning is performed to clean the bathtub return pipe 17 and the bathtub return pipe 18 with the fine bubbles 60 generated by passing through the water injection ejector 31. By periodically repeating the opening and closing of the water injection ejector air solenoid valve 32 to generate fine bubbles, coalescence of the bubbles can be prevented and the cleaning effect can be improved. For this reason, the amount of water injection required for cleaning can be reduced. According to the experiments conducted by the present inventors, the case where fine bubbles are continuously generated by periodically repeating the opening and closing of the water injection ejector air solenoid valve 32 every 2 seconds during water injection cleaning. In comparison, the amount of water injection could be reduced by about 25%.

  The state of the cleaning operation will be described with reference to FIG. FIG. 4 is an enlarged view of a main part of FIG. When the user instructs to fill the bathtub 15 with the remote controller 46, the water injection solenoid valve 44 is opened, and water is injected from the water injection pipe 26 to the bathtub 15 through the bathtub return pipe 17 and the bathtub return pipe 18. The amount of hot water filling is adjusted by the water level sensor 39 and the flow rate sensor 40. When the target amount of hot water filling is reached, the water injection solenoid valve 44 is closed and the hot water filling is completed at the position 50 of the hot water filling completion level.

  When the user drains water from the bathtub 15 for cleaning, the control unit 45 detects the detection value of the water level sensor 39, and when the water level falls below a predetermined first threshold value, the bath-side water supply pump 16, water is supplied to the bathtub 15, the bathtub return pipe 17, the bathtub return pipe 18, and the plate heat exchanger 11. When the bath water circulates, a pulsation operation is repeated in which the number of rotations of the bath-side water supply pump 16 reaches a maximum number of rotations of 6300 rpm for 2.5 seconds and about 0 rpm or 1000 rpm for the subsequent 1.5 seconds. To control. As a result, coalescence of the fine bubbles generated when the bath water passes through the circulation ejector 28 is prevented, and the bath water containing the fine bubbles is introduced into the plate heat exchanger 11 and circulated. Washing by circulation is continued for a certain time (for example, 60 seconds) or stopped when the water level of the bathtub 15 falls below the bathtub adapter 34 and the flow switch 47 detects no water. Thereafter, the water injection electromagnetic valve 44 is opened to start water injection, and the water injection ejector air electromagnetic valve 32 is controlled to open and close every 2 seconds, so that fine bubbles flow through both the bathtub outlet pipe 18 and the bathtub return pipe 17. 15 is used.

  Further, when the user drains water from the bathtub 15 for cleaning and the control unit 45 detects the detection value of the water level sensor 39 and the water level falls below a predetermined first threshold value, the water is automatically cleaned. Is started, the display device 462 of the remote controller 46 displays that cleaning is in progress.

  FIG. 6 is a flowchart of automatic cleaning in the first embodiment of the present invention. The cleaning operation will be described in more detail using this.

  In step S1, the water level of the bath water is transmitted as an electrical signal to the control unit 45 by the water level sensor 39, and the control unit 45 stores this as the current water level. Further, the control unit 45 determines a first threshold value as a cleaning operation start condition. The first threshold value may be a value stored in the control unit 45 in advance, or may be a relative value obtained by calculation using the pouring water filling completion water level 50 (for example, the filling water filling completion water level 50 minus 10 cm). Here, a description will be given assuming that the first threshold value is determined as the operation start water level Hmb.

  In step S2, the current water level stored in step S1 is compared with the operation start water level Hmb. If the current water level is equal to or lower than the operation start water level Hmb, the process proceeds to step S3 and the cleaning operation is started. Otherwise, the process returns to step S1, and the current water level is newly stored. The user drains water from the bathtub 15 for cleaning, and repeats until the water level drops and the condition is satisfied.

  In step S3, the control unit 45 generates an ON signal for the bath-side water pump 16 to drive it. Then, the water of the bathtub 15, the bathtub return piping 17, and the bathtub going-out piping 18 circulates.

  In step S4, the control unit 45 issues an ON signal for the circulation ejector air solenoid valve 29 to open it. Since water is circulated in step S3, the inside of the circulation ejector 28 has a negative pressure, and air that has passed through the circulation ejector air solenoid valve 29 is introduced by the circulation ejector 28 to generate fine bubbles. It begins to circulate with.

  In step S5, the control unit 45 issues a signal that repeats a cycle in which the bath-side water pump 16 operates at a maximum rotational speed of 6300 rpm for 2.5 seconds and operates at about 0 rpm or 1000 rpm for the subsequent 1.5 seconds. . That is, the bath-side water pump 16 is controlled in a pulsating manner. Since the maximum flow rate of water circulates while the bath-side water pump 16 is operating at the maximum rotation speed, the circulation ejector 28 has a negative pressure, and the circulation ejector 28 uses the circulation ejector air electromagnetic. Air that has passed through the valve 29 is introduced to generate fine bubbles, which circulate with water. By repeating the high-speed rotation signal for 2.5 seconds and the low-speed rotation signal for 1.5 seconds from the control unit 45 to the bath-side water supply pump 16, the timing for generating the fine bubbles and the stop or decrease of the fine bubbles This timing is repeated in a pulsating manner (periodically). As a result, coalescence of fine bubbles is prevented as described above, and a high cleaning effect can be obtained.

  In steps S6 and S7, conditions for ending the cleaning operation by circulation are determined. In step S6, the control unit 45 counts the elapsed time from the first ON signal generated by the circulation ejector air solenoid valve 29 in step S4, and this is the end time (here, the control unit 45). If it is equal to or longer than the bubble circulation time Tbc, the process proceeds to step S8. Otherwise, in step S7, the control unit 45 determines the presence / absence of water in the bathtub 15 from the signal of the presence / absence of water flow detected by the flow switch 47. If there is no bathtub water, the process proceeds to step S8. Otherwise, the determinations in steps S6 and S7 are repeated. If the condition for ending the cleaning operation by circulation is satisfied in either step S6 or 67 and the process proceeds to step S8, an OFF signal of the circulation ejector air solenoid valve 29 is issued, and then in step S9, the bath-side water pump 16 is turned off. An OFF signal is issued, and the operation proceeds to a water injection cleaning operation after step S10.

  In step S10, the controller 45 issues an ON signal for the water injection solenoid valve 44 and opens it. Then, water is poured from the bathtub return pipe 17 and the bathtub return pipe 18 toward the bathtub 15.

  In step S11, the control part 45 repeats the operation | movement which emits the ON signal and OFF signal of the water injection ejector air solenoid valve 32 every 2 second, and opens and closes this. Since the water flow is generated by step S10, the inside of the water injection pipe 26 has a negative pressure, the water injection ejector air solenoid valve 32 is opened and closed, and the air that has passed through the water injection ejector air solenoid valve 32 is introduced to make fine. Bubbles are generated and injected with water. By opening / closing the water injection ejector air solenoid valve 32 by the ON / OFF signal from the control unit 45 to the water injection ejector air electromagnetic valve 32, the timing for generating and stopping the fine bubbles is intermittently repeated. Thus, coalescence of fine bubbles can be prevented, and a high cleaning effect can be obtained.

  In step S12, an end condition for the cleaning operation by water injection is determined. The condition for ending the cleaning operation by water injection is set so as to obtain a necessary cleaning effect, and is stored in the control unit 45 in advance. Here, the scale of the end condition is the water injection amount, but it may be the water injection time.

  The control unit 45 counts the water injection amount from the first ON signal generated by the water injection ejector air solenoid valve 32 in step S11, and this is the water injection amount (here, the bubble water injection amount) stored in the control unit 45 in advance. If not less than Vbs), the process proceeds to step S13. Otherwise, the determination in step S12 is repeated. If the end condition is the water injection time in step S12, the water injection time is counted, and if it is equal to or longer than the water injection time previously stored in the control unit 45, the process may proceed to step S13.

  If the conditions for ending the washing operation with water injection are satisfied and the routine proceeds to step S13, an OFF signal for the water injection ejector air solenoid valve 32 is issued, and then an OFF signal for the water injection electromagnetic valve 44 is issued in step S14. This is the end of the cleaning operation.

  As described above, when the bath-side water pump 16 is operated at a maximum rotation speed of 6300 rpm for 2.5 seconds and then pulsated to repeat a cycle of maintaining about 0 rpm or 1000 rpm for the following 1.5 seconds, As a result of detailed analysis of the amount of residual oil adhering to the inner surface of the bathtub return pipe 17, the bathtub outlet pipe 18 and the plate heat exchanger 11, the decontamination rate is about 25 compared with the case of continuous operation. % Can be improved.

  Conventionally, the amount of water supplied through the water injection pipe 26 at the time of water injection cleaning has been set to flow at a constant flow rate (for example, 9 L) at which sufficient cleaning can be performed, or for a predetermined time (for example, 45 seconds). By controlling the bath-side water pump 16 so as to repeat high-speed / low-speed rotation in a pulsating manner, it was possible to prevent the coalescence of bubbles and improve the cleaning effect. It becomes possible to set the time. For example, it may be set to flow for 6 L or 34 seconds. Even if the previously set water injection amount (for example, a constant flow rate of 9 L or a fixed time of 45 seconds) is set to a value reduced by about 25% (for example, a fixed flow rate of 6 L or a fixed time of 34 seconds) by the pulsation control, The cleaning effect can be ensured, and about 25% of water can be saved.

Embodiment 2. FIG.
Next, a second embodiment of the present invention will be described with reference to FIG. 7. The description will focus on the differences from the first embodiment described above, and the same or corresponding parts will be denoted by the same reference numerals. To simplify.

  The cleaning operation of the second embodiment will be described with reference to FIG. In the same manner as in the first embodiment, after the user gives an instruction to fill the bathtub 15 with the remote controller 46, the water injection electromagnetic valve 44 is closed when the target amount of water injection is reached, and water injection is performed at the water injection completion water level 50. Hot water filling is complete.

  When the user presses the cleaning function selection button 461 of the remote controller 46 for cleaning, water is supplied by the bath-side water supply pump 16, and bath water is supplied to the bathtub 15, the bathtub return pipe 17, the bathtub return pipe 18, and the plate heat exchanger 11. Circulate. When the bath water circulates, a pulsation operation is repeated in which the number of rotations of the bath-side water supply pump 16 reaches a maximum number of rotations of 6300 rpm for 2.5 seconds and about 0 rpm or 1000 rpm for the subsequent 1.5 seconds. To control. As a result, coalescence of the fine bubbles generated when the bath water passes through the circulation ejector 28 is prevented, and the bath water containing the fine bubbles is introduced into the plate heat exchanger 11 and circulated. Washing by circulation is continued for a certain time (for example, 60 seconds) or stopped when the water level in the bathtub 15 falls below the bathtub adapter 34 and the flow switch 47 detects no water. Thereafter, the water injection electromagnetic valve 44 is opened to start water injection, and the water injection ejector air electromagnetic valve 32 is controlled to open and close every 2 seconds. Fine bubbles flow through both the bathtub return pipe 18 and the bathtub return pipe 17. It is configured to pour into the bathtub.

  In addition, when the user presses the cleaning function selection button 461 of the remote control 46 to start cleaning manually, the display device 462 of the remote control 46 displays that cleaning is being performed, and a voice to that effect. The generation device 463 also notifies by voice.

  FIG. 7 is a flowchart of cleaning in the second embodiment of the present invention. The above operation will be described in more detail using this.

  In step S15, it is determined whether or not the cleaning function selection button 461 of the remote controller 46 has been pressed. If the button is pressed, the process proceeds to step S3, and the bath-side water pump 16 starts operating in response to a signal from the control unit 45. Next, it is determined whether or not the elapsed time since the bath-side water pump 16 has been operated in step S16 has passed a predetermined time Tpc. If it has elapsed, the process proceeds to step S17. Determine presence or absence. The predetermined time Tpc after the operation of the bath-side water supply pump is, for example, a time (for example, 1 minute) in which the water in the bathtub return pipe 17 and the bathtub return pipe 18 can make a round, and the flow switch 47 is connected to the bathtub return pipe 17. The erroneous detection is prevented by the remaining water in the bathtub going-out pipe 18.

  In step S18, it is determined whether or not the flow switch 47 has detected the presence of bath water. If the presence of bath water has been detected, the process proceeds to step S4. Otherwise, the process proceeds to step S9.

  Steps S4 to S14 are the same as those in the first embodiment described above, and therefore the same reference numerals are given and description thereof is omitted.

  According to the second embodiment described above, an excellent cleaning effect can be obtained as in the first embodiment. Further, since the user can manually start the cleaning operation by pressing the cleaning function selection button 461 of the remote controller 46, the cleaning operation can be started promptly according to the user's desire. In addition, when the user manually starts the cleaning operation in this way, not only that the cleaning is being performed but also the display device 462 of the remote controller 46 is not only displayed but also the voice generation device 463 is notified by voice. Therefore, the user can be surely notified that the cleaning operation has been started, and the usability is improved.

DESCRIPTION OF SYMBOLS 10 Hot water storage tank 11 Plate type heat exchanger 15 Bath 16 Bath side water supply pump 17 Bath return pipe 18 Bath outlet piping 26 Injection pipe 28 Circulation ejector 29 Circulation ejector air solenoid valve 30 Circulation ejector air check valve 31 Injection ejector 32 Water Ejector Ejector Air Solenoid Valve 33 Water Ejector Ejector Air Check Valve 39 Water Level Sensor 44 Water Injection Electromagnetic Valve 45 Control Unit 46 Remote Control 461 Cleaning Function Selection Button

Claims (6)

A hot water storage type hot water heater capable of chasing the bath water in the bathtub by exchanging heat between the hot water stored in the hot water storage tank and the bath water in the bathtub with a heat exchanger,
A circulation line arranged to return from the bathtub to the bathtub through the heat exchanger;
A bath-side water supply pump for circulating the bath water in the circulation pipeline;
In the middle of the circulation line, upstream of the heat exchanger , fine bubbles having an average diameter of 10 μm to 100 μm for washing the heat exchanger and the inside of the circulation line are bathed. A circulating ejector that can be
A circulation ejector air solenoid valve that opens and closes an air intake connected to the circulation ejector;
When washing the heat exchanger and the inside of the circulation line by circulating bath water containing fine bubbles generated by the circulation ejector, the bath-side water supply pump is in a high rotation state and a low rotation state. And a control means for pulsating the bath-side water pump so that the amount of fine bubbles generated is changed periodically by repeating and
A hot water storage type water heater characterized by comprising:   The hot water storage type hot water heater according to claim 1, wherein the low rotation state includes a case where the number of rotations of the bath-side water pump is zero.   The hot water storage type hot water heater according to claim 1 or 2, wherein the control means makes the duration of the high rotation state longer than the duration of the low rotation state. Water level detecting means for detecting the water level of the bathtub;
Automatic cleaning means for automatically starting the cleaning when it is detected that the water level has fallen below a predetermined threshold;
A remote controller configured to allow a user to input a command to start the cleaning, the remote controller having a display device and a sound generator;
When the cleaning is started by inputting a command from the user to the remote controller, the automatic cleaning means displays the fact that the cleaning is being performed on the display device and also notifies the voice generation device by voice. When the cleaning is automatically started by the cleaning notifying means for notifying only by displaying on the display device that the cleaning is in progress,
The hot water storage type water heater according to any one of claims 1 to 3, further comprising: A water injection pipe connected to the circulation line and capable of injecting hot water into the circulation line,
A water injection solenoid valve for opening and closing the water injection pipe;
An ejector for water injection that is arranged in the middle of the water injection pipe and downstream of the water injection solenoid valve and can generate fine bubbles in the hot water in the water injection pipe for cleaning the inside of the circulation pipe When,
A water injection ejector air solenoid valve for opening and closing an air intake connected to the water injection ejector;
The hot water storage type hot water heater according to any one of claims 1 to 4, further comprising:   By repeatedly opening and closing the water injection ejector air solenoid valve when cleaning the inside of the circulation pipe by injecting hot water containing fine bubbles generated by the water injection ejector into the circulation pipe The hot water storage type hot water heater according to claim 5, further comprising second control means for operating the water injection ejector air solenoid valve so that the amount of fine bubbles generated periodically changes.

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