JP2016133285A - Bath hot water supply system and bath hot water supply control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bath hot water supply system and its control device in which a heat insulation efficiency of the bath hot water supply system including a heat insulation bath tub can be improved.SOLUTION: This invention comprises a bath tub having a heat insulation characteristic; an outgoing flow passage for supplying hot water from a heat source machine side toward the bath tub side; a return flow passage for supplying hot water from the bath tub side to the heat source machine side; a bypass flow passage for bypassing the hot water flowing from the outgoing flow passage to the bath tub to the return flow passage; a change-over mechanism for closing the bypass flow passage when a temperature of the flowing hot water is not lower than the prescribed temperature, opening the bypass flow passage when a temperature of the flowing hot water is lower than the prescribed temperature and closing the outgoing flow passage; and a control part. The control part does not perform a heat insulating operation when the control part confirms hot water in the bath tub for every prescribed time and receives an instruction for performing a heat insulating operation for additional boiling to keep its temperature at the set temperature, but performs a freezing-proof operation for circulating hot water in the outgoing flow passage and the return flow passage through the bypass flow passage.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a bath hot water supply system having a heat retaining function for hot water in a bathtub and a control device therefor.

  Conventionally, hot water in a bathtub is filled to a set water level (amount of water) and temperature, and after hot water filling, the hot water temperature is checked and replenished every predetermined time so as to keep the hot water in the bathtub at the set temperature (hereinafter referred to as the hot water) This is simply referred to as “interval heat insulation operation”.) Automatic bath operation is known (see, for example, Patent Document 1 and FIG. 3). Moreover, the heat insulation bathtub which makes heat dissipation small by providing the heat insulating bathtub heat insulating material in the outer surface of a bathtub is known (for example, refer patent document 2).

JP 2011-237060 A JP 2013-27456 A

  In the interval heat insulation operation of the bath automatic operation described above, the hot water in the bathtub is circulated through the bath circulation channel connecting the heat source machine and the bathtub in order to confirm the temperature of the hot water in the bathtub every predetermined time. Thereby, the hot water remaining in the bath circulation channel is discharged into the bathtub, and the hot water in the bathtub is absorbed. However, the discharge of hot water into the bathtub may reduce the temperature of the hot water in the bathtub depending on the temperature of the hot water. On the other hand, the interval heat retention operation has an advantage that it can also serve as a freeze prevention operation in winter when there is a risk of freezing of the bath circulation channel.

  Here, the above-described heat insulating bathtub is characterized in that the hot water temperature does not drop even if a certain time elapses. For this reason, although it may be considered that the interval heat insulation operation is unnecessary for the heat insulation bathtub, circulation of hot water in the bath circulation channel as the freeze prevention operation is necessary even for the heat insulation bathtub. However, when circulating in the bath circulation channel, the temperature of the hot water in the bathtub is lowered as described above, and as a result, an interval heat retaining operation is required.

  That is, when freeze prevention operation is performed in a heat-insulating bathtub with low heat dissipation, the hot water temperature in the bathtub may be unnecessarily lowered, and as a result, there is a problem of generating a loss of heat retention heat.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a bath hot water system and a control device for the bath hot water system that can improve the heat insulation efficiency of the bath hot water system provided with a heat insulating bathtub.

  In order to solve the above-described problems, the bath hot water system according to the present invention includes a bathtub having heat insulating properties, an outward flow path for supplying hot water from the heat source machine side to the bathtub side, and hot water from the bathtub side. A return flow path to be supplied to the heat source unit, a bypass flow path for bypassing hot water flowing from the forward flow path to the bathtub to the return flow path, and the bypass flow when the temperature of the circulating hot water is equal to or higher than a predetermined temperature. When the temperature of the circulating hot water is lower than the predetermined temperature, the switching mechanism section that opens the bypass flow path and closes the forward flow path and the hot water in the bathtub are confirmed every predetermined time, and set temperature When the instruction of the heat insulation operation to keep track of the temperature is received, the heat insulation operation is not performed, and the freeze prevention operation in which hot water in the forward flow path and the return flow path is circulated through the bypass flow path is performed. Control unit Characterized by comprising a.

  Further, the bath hot water control apparatus according to the present invention sets whether or not the bath has heat insulation, and the hot water from the bathtub side from the forward flow path for supplying hot water from the heat source machine side to the bathtub side. A bypass flow path for bypassing hot water flowing to the bathtub to the return flow path supplied to the heat source machine side, and when the temperature of the circulating hot water is higher than a predetermined temperature, the bypass flow path is closed, and the temperature of the circulating hot water is A setting unit that accepts a setting whether to have a switching mechanism unit that opens the bypass flow path and closes the forward flow path when the temperature is lower than the predetermined temperature, and confirms and sets the hot water in the bathtub every predetermined time. When receiving an instruction of a heat insulation operation for chasing to keep the temperature at the same time and accepting a setting in which the setting unit is a bathtub having the heat insulating property and a setting having the bypass flow path and the switching mechanism unit, Maintenance operation is not performed, characterized by comprising a control unit for freezing prevention operation in which the hot water of the forward channel and the return channel is circulated through the bypass passage.

  In the hot water supply system and the control device thereof according to the present invention, the heat retention efficiency of the hot water supply system including the heat insulating bathtub can be improved.

The schematic system block diagram of the bath hot-water supply system in this embodiment. The block diagram of the bath circulation flow-path switching apparatus connected with the bath circulation tool. Sectional drawing of the bath circulation flow path switching apparatus when the switching apparatus bypass flow path is closed. Sectional drawing of the bath circulation flow path switching apparatus when the switching apparatus bypass flow path opens. The flowchart explaining the interval heat insulation driving | operation of the bath automatic operation performed by the bath hot-water supply system in this embodiment.

  DESCRIPTION OF EMBODIMENTS An embodiment of a bath hot water system and a control device thereof according to the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a schematic system configuration diagram of a bath hot water supply system 1 in the present embodiment.
The bath hot water system 1 includes a bathtub 4 provided in the bathroom 3, a bath water heater 5 (water heater 5) provided outside the bathroom 3, and a bath circulation channel 6 that connects the water heater 5 and the bathtub 4. And mainly.

  A sheet-like heat insulating material is provided on the outer surface of the bathtub 4. Thereby, the bathtub 4 becomes a heat insulation bathtub which has heat insulation and small heat dissipation. As the heat insulating material, a polystyrene foam molded product, a foamed polyethylene sheet, or the like can be used. The heat insulating material is attached to the bathtub 4 via a fitting structure, an adhesive, a double-sided adhesive tape, or the like.

  Further, the bathtub 4 has a bath circulation tool 7 connected to the bath circulation channel 6. The bath circulator 7 is provided through the wall surface of the bathtub 4, and has a discharge port 7 a that discharges hot water (hot water or water) into the bathtub 4 and a suction port 7 b that sucks hot water in the bathtub 4. In the bathroom 3, a remote controller 8 for operating the water heater 5 and a currant 9 are provided.

  The water heater 5 as a heat source machine has a hot water storage tank 11 for storing hot water. The hot water storage tank 11 includes a heater 12 that heats the hot water in the hot water storage tank 11, and a hot water storage temperature sensor 13 that detects the hot water storage temperature in the hot water storage tank 11. A water supply pipe 15 for supplying city water to the hot water storage tank 11 is connected to the bottom of the hot water storage tank 11. A hot water discharge pipe 16 for discharging hot water from the hot water storage tank 11 is connected to the top of the hot water storage tank 11. The hot water discharge pipe 16 is connected to a water supply bypass pipe 18 branched from the water supply pipe 15 via a hot water supply mixing valve 17.

  The hot water supply mixing valve 17 mixes the hot water from the water supply bypass pipe 18 and the hot water from the outlet pipe 16 so as to reach a hot water supply set temperature. A hot water supply pipe 19 is further connected to the hot water supply mixing valve 17, and the hot water mixed by the hot water supply mixing valve 17 is guided to the currant 9. The hot water supply pipe 19 is provided with a hot water supply temperature sensor 21 that detects the temperature of hot water and a hot water supply flow rate counter 22 that detects the amount of hot water supply. Further, the water supply pipe 15 is provided with a water supply temperature sensor 23 for detecting the water supply temperature.

  The bath circulation channel 6 mainly includes a return pipe 31, a bath heat exchanger 33, and an outgoing pipe 32. The return pipe 31 forms a return flow path for supplying hot water from the bathtub 4 side to the heat source machine (hot water supply machine 5) side. Specifically, the return pipe 31 returns hot water (tub water) of the bathtub 4 sucked from the suction port 7 b of the bath circulator 7 to the bath heat exchanger 33. The bath heat exchanger 33 is provided in the upper part of the hot water storage tank 11 and heats the hot water by exchanging heat with the hot water in the hot water storage tank 11. The outgoing pipe 32 forms an outgoing flow path for supplying hot water from the heat source machine (hot water heater 5) side to the bathtub 4 side. Specifically, the forward pipe 32 supplies hot water heated by the bath heat exchanger 33 to the bathtub 4 side. The return pipe 31 includes a bath circulation pump 35 that sends hot water, a running water sensor 36 that detects whether hot water is circulating, and a bath temperature sensor that detects the temperature of hot water circulating through the forward pipe 32 and the return pipe 31. 37 and a water level sensor 38 for detecting the water level in the bathtub 4 are provided.

  Further, the bath circulation channel 6 includes a bath bypass pipe 40 and a bath three-way valve 39. The bath bypass pipe 40 forms a bypass flow path for bypassing hot water flowing from the return pipe 31 to the hot water heater 5 side to the forward pipe 32. The bath three-way valve 39 circulates hot water from the return pipe 31 to the bath heat exchanger 33, bypasses it to the forward pipe 32, or connects the return pipe 31 to either the bath heat exchanger 33 or the bath bypass pipe 40. Switch between closed and non-communication.

  The return pipe 31 is connected to a hot water filling pipe 41 branched from the hot water supply pipe 19 in order to supply hot water from the hot water supply pipe 19 to the bath circulation channel 6. The hot water filling pipe 41 prevents the hot water from flowing back from the return pipe 31, the hot water filling valve 42 that opens and closes the hot water filling pipe 41, the bath flow rate counter 43 that counts the amount of hot water supplied from the hot water filling pipe 41. And a check valve 44.

  The bath hot water supply system 1 includes a control unit 50 that electrically controls the bath hot water supply system 1. The control unit 50 has a calculation, a comparison, a storage function, and a clock function, and stores a program for controlling the water heater 5 in advance. In the present embodiment, the control unit 50 functions as a bath water supply control device.

  The control unit 50 acquires the detection values of the hot water storage temperature sensor 13, the hot water supply temperature sensor 21, the hot water supply flow rate counter 22, the hot water supply temperature sensor 23, the flowing water sensor 36, the bath temperature sensor 37, the water level sensor 38, and the bath flow rate counter 43, Based on this detected value, the heater 12, the hot water supply mixing valve 17, the bath circulation pump 35, the bath three-way valve 39, and the hot water filling valve 42 are controlled. In addition, the control unit 50 receives a user operation (instruction) via the remote controller 8 and controls each unit to execute the operation. For example, the control unit 50 performs a hot water supply operation, an automatic bath operation, a chasing operation, and the like based on a hot water supply set temperature, a bath set temperature, a set water level (amount of hot water) and the like operated by the remote controller 8.

  The bath circulation channel 6 includes a bath circulation channel switching device 2 disposed in the vicinity of the bath circulation tool 7 in the space behind the bathtub 4 in the bathroom 3.

FIG. 2 is a configuration diagram of the bath circulation channel switching device 2 connected to the bath circulation tool 7.
FIG. 3 is a cross-sectional view of the bath circulation channel switching device 2 when the switching device bypass channel 63 is closed.
FIG. 4 is a cross-sectional view of the bath circulation channel switching device 2 when the switching device bypass channel 63 is opened.

  The bath circulation channel switching device 2 (switching device 2) is provided to prevent discharge of cold water from the bath circulation channel 6 to the bathtub 4. As shown in FIG. 2, the switching device 2 mainly includes a switching device forward flow path 61, a switching apparatus return flow path 62, a switching apparatus bypass flow path 63, and a flow path switching mechanism unit 70.

  The switching device forward flow path 61 (forward flow path 61) is a part of the forward flow path of the bath circulation flow path 6 and supplies hot water from the hot water heater 5 side to the bathtub 4 side. The switching device return flow path 62 (return flow path 62) is a part of the return flow path of the bath circulation flow path 6 and supplies hot water from the bathtub 4 side to the water heater 5 side. The return flow path 62 extends in a substantially horizontal direction from the first horizontal flow path 65 extending substantially horizontally, the rising flow path 66 rising from the end of the first horizontal flow path 65, and the rising flow path 66 end. The second horizontal flow path 67 is provided in order from the bathtub 4 side. The switching device bypass channel 63 (bypass channel 63) forms a bypass channel that bypasses hot water flowing from the forward channel of the bath circulation channel 6 to the bathtub 4 to the return channel. Specifically, the bypass flow path 63 connects the forward flow path 61 to the return flow path 62 (rising flow path 66).

  The flow path switching mechanism unit 70 closes the bypass flow path 63 when the temperature of the flowing hot water is equal to or higher than the predetermined temperature, and opens the bypass flow path 63 when the temperature of the flowing hot water is lower than the predetermined temperature. 6 is a switching mechanism that closes 61.

  As shown in FIGS. 3 and 4, the flow path switching mechanism unit 70 mainly includes a temperature-sensitive switching valve 71 and a valve box 72. The temperature-sensitive switching valve 71 includes a shape memory alloy compression coil spring 74 (SMA (Shape Memory Alloy) spring 74) that expands and contracts according to the temperature of flowing hot water, a valve body 75 that is moved by the SMA spring 74, and the valve body. And a bias spring 76 that biases 75 in a direction opposite to the biasing force of the SMA spring 74. The temperature-sensitive switching valve 71 has a preset load adjusting screw 77 that adjusts the biasing force of the bias spring 76. The temperature sensitive switching valve 71 is configured such that the moving direction of the valve body 75 (the urging direction of the SMA spring 74 and the bias spring 76) is substantially horizontal.

  The SMA spring 74 extends when the temperature is equal to or higher than a predetermined temperature and closes the bypass flow path 63, and contracts when the temperature is lower than the predetermined temperature and opens the bypass flow path 63. The valve body 75 moves due to the force relationship between the SMA spring 74 and the bias spring 76. When the bypass flow path 63 is closed, a later-described bypass pipe 95 and a return pipe 84 (a portion serving as a partition wall 84e between the return flow path 62 and the bypass flow path 63) serve as valve seats. When the bypass channel 63 is opened, a connecting member 81 described later serves as a valve seat. Further, the valve box 72 is a tubular member whose tube axis extends in the substantially horizontal direction along the outer wall of the bathtub 4 when the switching device 2 is connected to the bath circulator 7. In the present embodiment, the connection member 81, the location where the inlet side connection port 82 b of the forward pipe 82 is formed, and the bypass pipe 95 function as the valve box 72 of the temperature sensitive switching valve 71.

  The SMA spring 74 has a low temperature feeling for the user even if it flows into the bathtub 4 and is lower than the temperature of the hot water supplied to the bathtub 4 that can be arbitrarily set by the user (bath set temperature). (For example, 30 ° C.) is designed as the shape recovery temperature corresponding to the predetermined temperature. Under an atmosphere lower than the shape recovery temperature, the biasing force of the SMA spring 74 is weaker than the biasing force of the bias spring 76, and the SMA spring 74 is pushed by the bias spring 76 and contracts. Under an atmosphere at or above the shape recovery temperature, the urging force of the SMA spring 74 is stronger than the urging force of the bias spring 76, and the SMA spring 74 extends against the bias spring 76.

  Next, the configuration of the switching device 2 will be described in more detail.

  The forward flow path 61 includes a connection member 81 and a forward pipe 82. The connection member 81 is a member that connects the forward pipe 32 and the forward pipe 82 of the bath circulation channel 6. The connection member 81 is connected to the forward pipe 32 through the inlet side connection port 81a. The connection member 81 is connected to the inlet side connection port 82b of the forward pipe 82 at the outlet side connection port 81b. The outgoing pipe 82 is connected to the outgoing side connecting pipe 7c of the bath circulator 7 through the outlet side connecting port 82c. Further, the connection member 81 has a forward flow path port 81 c at a connection portion with the forward pipe 82.

  Here, the forward flow path 61 is formed when the bypass flow path 63 is closed as shown in FIG. That is, when the temperature of the hot water flowing through the flow path switching mechanism unit 70 is equal to or higher than a predetermined temperature (when the SMA spring 74 extends beyond the shape recovery temperature), the valve body 75 returns to the bypass pipe 95 as a valve seat. It abuts on the tube 84 and closes the bypass flow path 63. Note that the “outward flow path” of the switching device 2 is not limited to the above-described configuration, and may include a part of the forward pipe 32 or a flow path on the downstream side of the forward pipe 82.

  The return flow path 62 includes a return pipe 84 that includes an elbow part. The return pipe 84 forms a first horizontal channel 65, a rising channel 66, and a second horizontal channel 67. The return pipe 84 includes an elbow pipe (elbow part) 90 that forms a part of the rising channel 66 and the second horizontal channel 67.

  The return pipe 84 is connected to the return side connection pipe 7d of the bath circulator 7 through the inlet side connection port 84b. The return pipe 84 is connected to the elbow inlet side connection port 90a (one end of the elbow pipe 90) at the outlet side connection port 84c, and at the elbow outlet side connection port 90b (the other end of the elbow pipe 90). The return pipe 31 is connected. In addition, the return pipe 84 has a bypass channel port 84 d at a connection portion between the first horizontal channel 65 and the rising channel 66. The “return flow path” of the switching device 2 is not limited to the above configuration, and may include a flow path upstream of the return pipe 84 or a part of the return pipe 31.

  The bypass flow path 63 includes a valve body 75, a bypass pipe 95 (including a portion that becomes a partition wall 84e between the return flow path 62 and the bypass flow path 63), a flow path side surface 77a of the preset load adjusting screw 77, and a bypass. It is comprised with the flow-path opening 84d. Here, the bypass flow path 63 is formed when the bypass flow path 63 is opened and the forward flow path 61 is closed as shown in FIG. That is, when the temperature of the hot water flowing through the flow path switching mechanism 70 is lower than a predetermined temperature (when the SMA spring 74 contracts below the shape recovery temperature), the valve body 75 is connected to the connection member 81 as a valve seat. Abutting, opening the bypass flow path 63 and closing the forward flow path 61.

  Such a switching device 2 prevents discharge of cold water from the bath circulation channel 6 to the bathtub 4 by the return channel 62 functioning as a steam-water separation unit. That is, by providing the rising flow channel 66 between the first horizontal flow channel 65 and the second horizontal flow channel 67 and forming a height difference between the first horizontal flow channel 65 and the second horizontal flow channel 67, The air in the bathtub 4 can be mainly sucked without circulating a small amount of residual water in the first horizontal flow path 65 in the return pipe 31 when the bath circulation pump 35 is driven. Such a steam / water separation unit can prevent circulation only with residual water in the bath circulation channel 6 when the bathtub 4 is in an empty state, for example.

  In addition, the one where the internal diameter of the 1st horizontal flow path 65 and the internal diameter of the standing flow path 66 are larger exhibits the function of a steam-water separation part. Further, the first horizontal flow path 65 and the second horizontal flow path 67 are not completely horizontal, and may be accompanied by a slight inclination. Further, the rising channel 66 preferably rises substantially perpendicular to the first horizontal channel 65 and the second horizontal channel 67, but the first horizontal channel 65 and the second horizontal channel 67 have a height difference. If possible, it may stand up at an angle other than vertical.

  Next, the bath automatic operation performed by the bath water supply system 1 in the present embodiment will be described. The bath automatic operation is a control for automatically filling, pouring and replenishing hot water in the bathtub 4 so as to keep the hot water in the bathtub 4 at a set water level (amount of hot water) and temperature. Moreover, the bath automatic operation includes an interval heat retaining operation for controlling the hot water in the bathtub to be kept at a set temperature after filling. This interval heat-retaining operation is a control for confirming whether the hot water in the bathtub 4 is at a set temperature every predetermined time, and performing chasing if necessary.

  In such a hot water supply system 1 in the present embodiment, when the bathtub 4 is a heat insulating bathtub and has the bath circulation channel switching device 2, the heat insulation efficiency is improved by suitably controlling the interval heat insulation operation. Can do. Hereinafter, the interval heat insulation operation of bath automatic operation is demonstrated concretely.

  FIG. 5 is a flowchart for explaining the interval heat retention operation of the automatic bath operation performed by the bath hot water supply system 1 in the present embodiment. In FIG. 5, only the interval heat-retaining operation after the user is instructed to perform the automatic bathing operation and the hot water is filled so as to reach the set water level and temperature in the bathtub 4 will be described. Is omitted.

In step S1, the control unit 50 determines whether or not the automatic warming time t _KW has elapsed. The automatic heat retention time t _KW is a time for automatically maintaining the hot water in the bathtub 4 at the set water level and temperature after the bath automatic operation is instructed and the hot water is filled. For example, the time set by the user via the remote controller 8 (For example, 1 to 6 hours). When it is determined that the automatic heat retention time t _KW has elapsed (YES in Step S1), the controller 50 ends the interval heat retention operation, that is, the bath automatic operation.

When it is determined that the automatic heat retention time t _KW has not yet elapsed (NO in step S1), the control unit 50 determines in step S2 whether or not an operation instructing driving from the user has been accepted via the remote controller 8. Do. The operation to be performed here is an operation related to the automatic bath operation, and is reheating, hot hot water, hot water, and hot water. When it is determined that the driving operation has been accepted (YES in step S2), the control unit 50 performs the driving based on the operation in steps S3 to S6. Thereafter, the processing returns to the automatic heat retention time elapsed determination step S1.

  On the other hand, when it determines with the control part 50 not receiving driving | operation operation (NO of step S2), in order to confirm the present water level in the bathtub 4, in step S7, the remaining hot water level is acquired from the water level sensor 38. FIG. In step S <b> 8, the control unit 50 determines whether or not the acquired water level matches the automatic water replenishment condition for automatically pouring water. The automatic water replenishment condition is that the current water level is lower than the set water level set by the user by a certain level or more, and when this condition is met, pouring (tap water operation) is automatically executed. When it determines with the control part 50 being in agreement with automatic water replenishment conditions (YES of step S8), the amount of water replenishment is calculated in step S9, and the hot water is poured into the bathtub 4 based on this. Thereafter, the processing returns to the automatic heat retention time elapsed determination step S1.

  When it is determined that the control unit 50 does not match the automatic water replenishment condition (NO in step S8), in step S10, is the setting that the bathtub 4 is an adiabatic bathtub and the setting that includes the bath circulation channel switching device 2 made? Determine whether or not. This setting is, for example, an initial setting performed via the remote controller 8 at the time of installing the hot water supply system 1, and the remote controller 8 includes (1) a setting as to whether or not the bathtub 4 is an insulated bathtub, and (2) The setting of the presence / absence of the bath circulation channel switching device 2 is received (details will be described later).

When the control unit 50 determines that the bathtub 4 is set to be an insulated bathtub and the setting having the bath circulation channel switching device 2 (YES in step S10), the freeze prevention time _tFP has elapsed in step S11. It is determined whether or not. The freeze prevention time t _FP is a cycle of circulating hot water in the flow path 6 in order to prevent freezing of hot water staying in the bath circulation flow path 6 and is, for example, 30 minutes. When it is determined that the freeze prevention time t _FP has not elapsed (NO in step S11), the control unit 50 returns to the automatic heat retention time elapsed determination step S1.

On the other hand, when it is determined that the freeze prevention time t _FP has elapsed (YES in step S11), the control unit 50 starts a bypass circulation operation for circulating hot water in the bath circulation passage 6 in step S12. Specifically, the control unit 50 operates the bath circulation pump 35 to switch the bath three-way valve 39 so as to bypass the hot water from the return pipe 31 to the forward pipe 32 and circulate the hot water. At this time, it is considered that the hot water in the bath circulation channel 6 for which the freeze prevention time t _FP has passed is lower than the shape recovery temperature of the SMA spring 74. Since the flow path switching mechanism 70 opens the bypass flow path 63 and closes the forward flow path 61, hot water in the bath circulation flow path 6 is not discharged to the bathtub 4.

In step S13, the control unit 50, whether a predetermined time t _D has elapsed, or the temperature TH obtained from the bath temperature sensor 37 and determines whether or not the determination temperature TH _D above. Predetermined time t _D used for determining is the duration of bypass circulation operation required for freezing prevention, is set to, for example, 10 minutes. Determining temperature TH _D is the temperature at which it can be determined that there is no possibility that the hot water bath circulation flow path is frozen. To perform reliably the above determination, the determination temperature TH _D is preferably set to a shape recovery temperature or less and no possibility of the temperature of the freezing of the SMA spring 74 of the flow path switching mechanism 70, for example, about 15 ℃ more preferable.

When the control unit 50 determines that the predetermined time t _D has not elapsed and the temperature TH is not equal to or lower than the determination temperature TH _D (NO in step S13), the predetermined time t _D elapses or the temperature TH is It waits until the determination temperature TH _D above. On the other hand, when the control unit 50 is the predetermined time _{t D} has elapsed, or the temperature TH is determined to be the determination temperature TH _D above (YES in step S13), and stops the bypass circulation operation in step S14, the freeze prevention time In the determination step S11, the freeze prevention timer for determining the elapse of the freeze prevention time _tFP is cleared. Thereafter, the processing returns to the automatic heat retention time elapsed determination step S1.

  Note that the freeze prevention operation (freezing prevention time elapsed determination step S11 to timer clear step S14) is preferably performed only in winter when there is a risk of freezing. The control unit 50 determines whether or not the winter can be considered from conditions such as the average hot water temperature and the outside air temperature, and does not perform the automatic interval heat insulation operation except during the winter, and does not perform the freeze prevention operation.

On the other hand, in the setting determination step S10, when the control unit 50 determines that the bathtub 4 is not a heat insulating bathtub or has not been set to have the bath circulation channel switching device 2 (NO in step S10), in step S15. Then, it is determined whether or not the boiling time t _RH in the interval heat retention operation has elapsed. The boiling time t _RH is a time for performing an operation of automatically boiling hot water in the bathtub 4, and is set to 20 minutes, for example. When it is determined that the boiling time t _RH has not elapsed (NO in step S15), the control unit 50 returns to the automatic heat retention time elapsed determination step S1.

On the other hand, when it is determined that the boiling time t _RH has elapsed (YES in step S15), the control unit 50 starts the heat retaining operation in step S16. Specifically, the control unit 50 operates the bath circulation pump 35 to switch the bath three-way valve 39 so that hot water from the return pipe 31 is circulated to the bath heat exchanger 33, and the hot water in the bathtub 4 is supplied to the bath circulation flow path 6. To circulate. The control unit 50 performs chasing until the temperature TH acquired from the bath temperature sensor 37 reaches the set temperature. Thereafter, the process returns to the automatic heat retention time elapsed determination step S1, and is repeated until the interval heat retention operation is completed.

  In such a hot water supply system 1 in the present embodiment, when the bathtub 4 is a heat insulating bathtub and has the bath circulation channel switching device 2, an unnecessary automatic interval heat insulation operation is performed due to the small heat dissipation, It is possible to prevent the hot water temperature in the bathtub 4 from being lowered by inadvertently flowing the cold water in the bath circulation channel 6 into the bathtub 4. Furthermore, since the bath hot water supply system 1 has the bath circulation channel switching device 2, it is possible to perform the freeze prevention operation without allowing the cold water in the bath circulation channel 6 to flow into the bathtub 4, thereby reducing the heat retention heat loss. Both generation and freezing prevention can be achieved. As a result, the system efficiency of the whole bath hot water supply system 1 can be improved.

  Here, in order to give the control unit 50 as a bath hot water control device versatility, the control unit 50 performs settings regarding whether or not the bathtub 4 is a heat insulating bathtub and settings regarding whether or not the bath circulation channel switching device 2 is present. It is also effective in that an appropriate interval heat-retaining operation can be performed according to this setting. Table 1 shows four patterns that can be set via the remote controller 8 and types of operation according to the settings.

  When the bathtub 4 is a non-insulated bathtub (a bathtub in which no heat insulating material is provided), and the bath circulation channel switching device 2 is set to be absent or present (patterns 1 and 2), the control unit 50 performs interval heat insulation operation. I do. That is, the automatic heat retention time elapsed determination step S1 to the refilling condition determination step S8, the boiling time elapsed time determination step S15, and the heat retention operation start step S16 of FIG. 5 are performed. Thereby, at the time of execution of the interval heat insulation operation, the heat insulation operation which also serves as the freeze prevention operation is performed.

Further, when the bathtub 4 is a heat insulating bathtub and the bath circulation channel switching device 2 is set to be absent (pattern 3), the interval heat insulation operation similar to the patterns 1 and 2 is performed. Since the bathtub 4 is an insulated bathtub, and the fall of the hot water temperature in the bathtub 4 is small, the heat insulation operation is unnecessary. However, the control part 50 performs interval heat insulation operation also as the freeze prevention operation in the bath circulation flow path 6. In this case, since the hot water temperature of the bathtub 4 is less likely to be lower than when the bathtub 4 is a non-insulated bathtub, the boiling time t _{RH in} the boiling time elapsed determination step S15 is greater than when the bathtub 4 is a non-insulated bathtub. It is preferable to set the length too long.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  For example, instead of the SMA spring 74, a wax thermoelement that expands when the temperature is equal to or higher than the shape recovery temperature and contracts when the temperature is lower than the shape recovery temperature may be used.

  In addition, the water heater 5 as a heat source device is provided with a heat pump type heating device outside the hot water storage tank 11 to circulate and heat the hot water in the hot water storage tank 11, or the bath heat exchanger 33 is arranged outside the hot water storage tank 11. The hot water in the hot water storage tank 11 is circulated to the primary side of the bath heat exchanger 33, or there is an instantaneous heat exchanger (bath heat exchanger) that heats the water supply or bath water with a gas burner or an oil burner. It may be configured as described above.

DESCRIPTION OF SYMBOLS 1 Bath hot water supply system 2 Bath circulation flow path switching device 3 Bathroom 4 Bathtub 5 Bath hot water supply machine 6 Bath circulation flow path 8 Remote control 31 Return pipe 32 Outward pipe 33 Bath heat exchanger 35 Bath circulation pump 37 Bath temperature sensor 38 Water level sensor 40 Bath Bypass pipe 39 Bath three-way valve 50 Control unit 61 Switching device forward flow path 62 Switching device return flow path 63 Switching apparatus bypass flow path 70 Flow path switching mechanism

Claims (4)

A bathtub with heat insulation,
An outward flow path for supplying hot water from the heat source machine side to the bathtub side;
A return flow path for supplying hot water from the bathtub side to the heat source machine side;
A bypass flow path for bypassing hot water flowing from the forward flow path to the bathtub to the return flow path;
A switching mechanism that closes the bypass flow path when the temperature of the flowing hot water is equal to or higher than a predetermined temperature, and opens the bypass flow path and closes the forward flow path when the temperature of the flowing hot water is lower than the predetermined temperature When,
If the hot water in the bathtub is checked every predetermined time and an instruction for a warming operation to keep warm at a set temperature is received, the warming operation is not performed, and hot water in the forward flow path and the return flow path is not changed. A bath hot-water supply system comprising: a control unit that performs a freeze-preventing operation to circulate through the bypass flow path.   The bath hot water supply system according to claim 1, wherein the control unit performs the freeze prevention operation when it can be regarded as winter. Setting whether or not the bathtub has heat insulation, and from the forward flow path for supplying hot water from the heat source machine side to the bathtub side to the return flow path for supplying hot water from the bathtub side to the heat source machine side A bypass channel for bypassing the hot water flowing to the side, and the bypass channel is closed when the temperature of the circulating hot water is higher than a predetermined temperature, and the bypass channel is closed when the temperature of the circulating hot water is lower than the predetermined temperature A setting unit that receives a setting as to whether or not to have a switching mechanism unit that opens and closes the forward flow path,
The hot water in the bathtub is checked every predetermined time, an instruction of a heat insulation operation for chasing so as to keep the temperature at a set temperature is accepted, and the setting and the bypass flow path and the switching that the setting portion is the heat insulating bathtub A control unit that performs a freeze prevention operation that circulates the hot water in the forward flow path and the return flow path through the bypass flow path without performing the heat retaining operation when a setting having a mechanism portion is received. A hot water supply control device characterized by that.   The said control part performs the said heat retention operation, when the setting which the said setting part is a bathtub which does not have the said heat insulation is received, or when the setting which does not have the said bypass flow path and the said switching mechanism part is received. 3. The bath hot water control apparatus according to 3.

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