Soup mixing device

Abstract

To provide a hot-water / water mixing device capable of stable temperature control.SOLUTION: A hot-water / water mixing device 10 comprises: a water supply pipe 1C; a hot-water supply pipe 1H; a mixing pipe 1M; flow rate control valves 4C, 4H; temperature sensors 3C, 3H; flow rate sensors 5C, 5H; a setting part 70; and a control part 80. The control part 80 compares a water side opening degree VPc indicating an opening degree of a water supply path opened by the flow rate control valve 4C, and a hot-water side opening degree VPh indicating an opening degree of a hot-water supply path opened by the flow rate control valve 4H, calculates and updates target flow rates QC1, QH1 of the flow rate control valves 4C, 4H in either the water supply path or the hot-water supply path having a smaller opening degree based on flow rates QC, QH acquired by the flow rate sensors 5C, 5H of either the water supply path or the hot-water supply path having a larger opening degree of the water side opening degree VPc and the hot-water side opening degree VPh, and controls the flow rate control valves 4C, 4H having a smaller one of the opening degrees VPc, VPh with the target flow rates QC1, QH1 of the flow rate control valves 4C, 4H having a smaller one of the updated opening degrees VPc, VPh, as a reference.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a hot and cold water mixing device. [Background technology]

[0002] Patent Document 1 discloses a hot and cold water mixing device. This hot and cold water mixing device mixes water supplied from a water supply source and hot water supplied from a hot water supply source, and discharges mixed water at a predetermined temperature and a predetermined flow rate. This hot and cold water mixing device has a diaphragm-type constant flow valve arranged in the water supply passage and the hot water supply passage. This constant flow valve enables the hot and cold water mixing device to stabilize temperature control and flow rate control when there is a pressure fluctuation, such as when at least one of the pressure of the water supply source and the pressure of the hot water supply source becomes lower than a predetermined pressure, or when the pressure difference between the pressure of the water supply source and the pressure of the hot water supply source becomes large. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-183986 A Summary of the Invention [Problem to be solved by the invention]

[0004] The hot and cold water mixing device of Patent Document 1 requires the provision of a pressure chamber in order to drive a diaphragm-type constant flow valve by pressure fluctuation, which results in a complex flow path for the hot and cold water.

[0005] In consideration of the above circumstances, the present disclosure aims to provide a hot water mixing device that can perform stable temperature control without using a constant flow valve that detects pressure fluctuations. [Means for solving the problem]

[0006] The hot water mixing device of the present disclosure includes a water supply channel connected to a water supply source and through which water supplied from the water supply source flows, a hot water supply channel connected to a hot water supply source and through which hot water supplied from the hot water supply source flows, a mixing channel connected to the water supply channel and the hot water supply channel and through which mixed water obtained by mixing water supplied from the water supply channel and hot water supplied from the hot water supply channel flows, a water-side flow rate adjustment unit that adjusts the flow rate of water in the water supply channel, a hot water-side flow rate adjustment unit that adjusts the flow rate of hot water in the hot water supply channel, a water-side information acquisition unit that acquires water information including the temperature and flow rate of water in the water supply channel, a hot water-side information acquisition unit that acquires hot water information including the temperature and flow rate of hot water in the hot water supply channel, a setting unit that sets the temperature and flow rate of the mixed water in the mixing channel, and a setting unit that acquires setting information from the setting unit, the water temperature of the water-side information acquisition unit, and the hot water information of the hot water-side information acquisition unit. and a control unit that calculates a target flow rate of the water-side flow rate adjustment unit and a target flow rate of the hot water side flow rate adjustment unit based on the temperature of the water supply passage, and controls the water-side flow rate adjustment unit and the hot water side flow rate adjustment unit, wherein the control unit compares a water side opening indicating the amount by which the water-side flow rate adjustment unit opens the water supply passage with a hot water side opening indicating the amount by which the hot water side flow rate adjustment unit opens the hot water passage, and calculates and updates the target flow rate of the flow rate adjustment unit for either the water supply passage or the hot water passage which has a smaller opening based on the flow rate acquired by the information acquisition unit for either the water supply passage or the hot water passage which has a larger opening between the water side opening and the hot water side opening, and controls the flow rate adjustment unit on the side with the smaller opening based on the updated target flow rate of the flow rate adjustment unit on the side with the smaller opening. [Brief description of the drawings]

[0007] [Figure 1] 1 is a schematic diagram showing an entire hot and cold water mixing device according to an embodiment. [Diagram 2] 4 is a flowchart showing a flow of temperature control and flow rate control of the hot and cold water mixing device according to the embodiment. [Diagram 3] 3 is a flowchart showing a procedure for calculating each target flow rate in FIG. 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Next, a hot and cold water mixer according to an embodiment will be described with reference to the drawings. The hot and cold water mixer 10 is installed in a kitchen or a bathroom. The hot and cold water mixer 10 supplies mixed water at a predetermined temperature and flow rate to a discharge pipe attached to a sink or a washing area. As shown in FIG. 1, the hot and cold water mixer 10 includes a water supply pipe 1C, a hot water supply pipe 1H, and a mixing pipe 1M.

[0009] The water supply pipe 1C is connected to a water supply source C and has a water supply passage formed therein. Water at, for example, 20°C flows through the water supply passage. The water supply pipe 1C has, in order from the upstream side to the downstream side, a check valve 2C, a temperature sensor 3C, a flow rate control valve 4C, and a flow rate sensor 5C.

[0010] The hot water supply pipe 1H is connected to a hot water supply source H such as a gas water heater, and has a hot water supply path formed therein. Hot water at, for example, 60°C flows through the hot water supply path. The hot water supply pipe 1H has, in order from upstream to downstream, a check valve 2H, a temperature sensor 3H, a flow rate control valve 4H, and a flow rate sensor 5H, similar to the water supply pipe 1C described above.

[0011] The mixing pipe 1M is connected to the water supply pipe 1C and the hot water supply pipe 1H, and a mixing water channel is formed inside. The mixing water channel carries mixed water, which is a mixture of water supplied from the water supply channel and hot water supplied from the hot water supply channel. The mixing pipe 1M has, in order from the upstream side to the downstream side, a temperature sensor 3M and an opening / closing valve 6M. The downstream side of the mixing pipe 1M is connected to various discharge pipes (not shown).

[0012] The temperature sensors 3C, 3H, and 3M are thermistors. The temperature sensors 3C, 3H, and 3M detect the temperature of the water in the water supply pipe 1C, the temperature of the hot water in the hot water supply pipe 1H, and the temperature of the mixed water in the mixing pipe 1M. The temperature sensors 3C and 3H correspond to a part of the water side information acquisition unit and the hot water side information acquisition unit.

[0013] The flow rate control valves 4C, 4H are valve bodies that are rotationally driven by a stepping motor to adjust the cold water side opening VPc and the hot water side opening VPh by widening or narrowing the flow paths of the cold water supply passage and the hot water supply passage. The flow rate control valves 4C, 4H are of the same shape and size. Here, the opening of the flow rate control valves 4C, 4H refers to the degree to which the flow rate control valves 4C, 4H are open, and is the size of the flow path area that changes due to the flow rate control valves 4C, 4H. In the case of flow rate control valves that change the flow path area by rotational drive, the opening of the flow rate control valves 4C, 4H can be grasped by the rotation angle. The cold water side opening VPc and the hot water side opening VPh are based on a predetermined opening, not the difference (amount of change) between the opening before and after the flow rate adjustment. The flow rate control valves 4C, 4H adjust the flow rate Q of the water flowing through the water supply passage. C , and the flow rate of hot water flowing through the hot water supply passage Q H The flow rate control valves 4C and 4H correspond to a cold water side flow rate control portion and a hot water side flow rate control portion.

[0014] The on-off valve 6M is an electromagnetic valve. The on-off valve 6M opens and closes the flow path of the mixing channel to allow or stop the mixed water from flowing through the mixing channel.

[0015] The flow rate sensors 5C and 5H are impeller-type flow meters. The impellers of the flow rate sensors 5C and 5H are rotated by the water flowing through the water supply passage and the hot water flowing through the hot water supply passage, and the flow rate Q of the water is measured based on the number of rotations of the impellers. C , hot water flow rate Q H The flow rate sensors 5C and 5H correspond to a part of the cold water side information acquiring unit and the hot water side information acquiring unit.

[0016] The hot and cold water mixing device 10 comprises a setting unit 70 and a control unit 80. The setting unit 70 is a remote control installed in the kitchen or bathroom. The setting unit 70 has various operation buttons (not shown) and a display panel that displays the temperature and flow rate of the mixed water in the mixing water channel. When the user inputs the desired setting values ​​for the temperature and flow rate of the mixed water using the operation buttons, the setting unit 70 transmits the setting information to the control unit 80.

[0017] The control unit 80 is connected by wires to the temperature sensors 3C, 3H, and 3M, the flow rate sensors 5C and 5H, the flow rate control valves 4C and 4H, the on-off valve 6M, and the setting unit 70. The control unit 80 receives and stores the temperature information detected by the temperature sensors 3C and 3H, and the flow rate information detected by the flow rate sensors 5C and 5H. The temperature information detected by the temperature sensor 3C and the flow rate information detected by the flow rate sensor 5C correspond to water information. The temperature information detected by the temperature sensor 3H and the flow rate information detected by the flow rate sensor 5H correspond to hot water information. The control unit 80 also stores the water side opening degree VPc of the flow rate control valve 4C, the hot water side opening degree VPh of the flow rate control valve 4H, and the open / close state of the on-off valve 6M. Furthermore, the control unit 80 previously stores how much the opening degrees VPc and VPh of the flow rate control valves 4C and 4H are to be adjusted with respect to the target flow rates of the water flowing through the water supply passage and the hot water flowing through the hot water supply passage.

[0018] When the control unit 80 receives setting information for starting or stopping discharge from the setting unit 70, it sends a control signal to the on-off valve 6M to open or close the on-off valve 6M. The control unit 80 calculates the target flow rates of water to be flowed in the water supply passage and hot water to be flowed in the hot water supply passage based on the setting information from the setting unit 70, the temperature information from the temperature sensors 3C and 3H, and the flow rate information from the flow rate sensors 5C and 5H, and sends a control signal to the flow rate adjustment valves 4C and 4H to adjust the openings VPc and VPh of the flow rate adjustment valves 4C and 4H.

[0019] The control unit 80 controls the temperature and flow rate of the mixed water in the mixing flow channel as shown in FIG. 2. First, the control unit 80 controls the set temperature T M and set flow rate Q M The set temperature T M and set flow rate Q M corresponds to the setting information. Next, the control unit 80 calculates the temperature T of the water currently in the water supply passage detected by the temperature sensors 3C and 3H. C and the temperature of the hot water in the hot water supply passage T H , the current water flow rate Q of the water supply line detected by the flow rate sensors 5C and 5H C and the flow rate of hot water in the hot water supply passage Q H Next, the control unit 80 receives the setting information T M ,QM , current temperature information T C ,T H , and current flow rate information Q C ,Q H Based on this, the target flow rate Q of water to be discharged into the water supply channel is C1 , and the target flow rate Q of hot water to be supplied to the hot water supply passage H1 (Step S3) Calculate the flow rate Q of water flowing through the water supply channel. C is the same as the flow rate of water flowing through the flow control valve 4C of the water supply passage. Also, the flow rate of hot water flowing through the hot water supply passage Q H is the same as the flow rate of hot water flowing through the flow rate adjustment valve 4H of the hot water supply passage. The details of this calculation method will be described later.

[0020] Next, the control unit 80 calculates the target flow rate Q C1 ,Q H1 Based on the target flow rate Q calculated in step S3, the control unit 80 determines the adjustment amount of the flow rate adjustment valves 4C, 4H based on the opening degrees VPc, VPh of the flow rate adjustment valves 4C, 4H stored in advance (step S4). C1 ,Q H1 The adjustment amount of the flow control valves 4C and 4H is determined so that the flow rate is not the same as the target flow rate Q C1 ,Q H1 The control unit 80 suppresses the amount of change to the openings VPc, VPh that can provide the same flow rate as the flow rate control valves 4C, 4H to about 80% based on the determined adjustment amount of the flow rate control valves 4C, 4H (step S5), and returns to step S1 of receiving the setting information and repeats the process. The number of repetitions may be set to a predetermined number of times, or may be made variable according to the setting information. When the number of repetitions of steps S1 to S5 has reached the final number, the control unit 80 suppresses the amount of change to the calculated target flow rate Q in step S4. C1 ,Q H1 The adjustment amounts of the flow rate control valves 4C and 4H are determined so that the flow rate is the same as that of the flow rate control valves 4C and 4H.

[0021] Target flow rate Q of the flow control valve 4C in the water supply line C1 , and the target flow rate Q of the flow control valve 4H of the hot water supply line H1 The calculation method of the set temperature TM is the temperature of the hot water in the hot water supply passage T H In step S301, it is determined whether the set temperature T M The temperature of the water is T H If it is determined that the flow rate is higher than the target flow rate Q C1 is calculated to be zero (step S302), and the target flow rate Q of the flow control valve 4H is H1 Set the flow rate Q M (step S303), and the process proceeds to step S4, in which the adjustment amounts of the flow rate adjustment valves 4C and 4H are determined. M The temperature of the water is T H or set temperature T M The temperature of the water is T H If it is determined that the temperature is lower than the set temperature T M is the water temperature T C In step S304, it is determined whether the set temperature T M is the water temperature T C If it is determined that the flow rate is lower than the target flow rate Q C1 Set the flow rate Q M (Step S305), and the target flow rate Q of the flow control valve 4H is calculated as H1 is calculated to be zero (step S306), and the process proceeds to step S4 in which the adjustment amounts of the flow rate adjustment valves 4C and 4H are determined.

[0022] In step S304, the set temperature T M is the water temperature T C or set temperature T M is the water temperature T C If it is determined that the flow rate is higher than the target flow rate Q C1 is calculated using the following formula 1 (step S307), and the target flow rate Q of the flow control valve 4H is set. H1 is calculated using the following formula 2 (step S308). Q C1 =(T H -TM )×Q M / (T H -T C ) … Formula 1 Q H1 =Q M -Q C1 … Formula 2

[0023] Next, the control unit 80 calculates the current hot water temperature T H It is determined whether the hot water temperature T is higher than a predetermined threshold (step S309). The threshold is about 40 degrees. H is determined to be lower than the threshold value (determined as No), the control unit 80 C1 , and the target flow rate Q calculated in step S308 H1 The process proceeds to step S4, in which the amount of adjustment of the flow rate adjustment valves 4C, 4H is determined based on the above. In this case, even if the pressure of the water supply source C and the pressure of the hot water supply source H are lower than the predetermined pressure or the pressure difference is large, there is no risk of the temperature of the mixed water in the mixing flow path changing suddenly, so the control unit 80 omits recalculation of the target flow rate, which will be described later.

[0024] In step S309, the temperature of the hot water T H is determined to be equal to or higher than the threshold value (determined as Yes), the control unit 80 determines whether the cold water side opening VPc of the flow rate control valve 4C is greater than the hot water side opening VPh of the flow rate control valve 4H (step S310). In step S310, if it is determined that the cold water side opening VPc of the flow rate control valve 4C is equal to the hot water side opening VPh of the flow rate control valve 4H or the cold water side opening VPc is greater than the hot water side opening VPh (determined as Yes), the control unit 80 sets the target flow rate Q of the flow rate control valve 4H. H1 The flow rate Q of water flowing through the flow control valve 4C C Based on this, the following formula 3 is used to recalculate and update (step S311). Q H1 =(T M -T C )×Q C / (T H -T M ) … Formula 3 Next, the control unit 80 calculates the target flow rate Q of the flow rate adjustment valve 4C calculated in step S307. C1 , and the target flow rate Q of the flow rate control valve 4H calculated and updated in step S311 H1 Based on this, the flow proceeds to step S4 in which the adjustment amounts of the flow rate adjustment valves 4C and 4H are determined.

[0025] In step S310, if it is determined that the cold water side opening degree VPc of the flow rate control valve 4C is smaller than the hot water side opening degree VPh of the flow rate control valve 4H (if it is determined as No), the control unit 80 adjusts the target flow rate Q C1 The flow rate Q of hot water flowing through the flow control valve 4H H Based on this, the following formula 4 is used to recalculate and update (step S313). Q C1 =(T H -T M )×Q H / (T M -T C ) … Equation 4 Next, the control unit 80 calculates the target flow rate Q of the flow rate adjustment valve 4H calculated in step S308. H1 , and the target flow rate Q of the flow control valve 4C calculated and updated in step S313 C1 Based on this, the flow proceeds to step S4 in which the adjustment amounts of the flow rate adjustment valves 4C and 4H are determined.

[0026] Next, the operation and effect of this embodiment will be described. The hot water mixer 10 of this embodiment includes a water supply pipe 1C connected to a water supply source C and forming a water supply path through which water supplied from the water supply source C flows, a hot water supply pipe 1H connected to a hot water supply source H and forming a hot water supply path through which hot water supplied from the hot water supply source H flows, and a mixing pipe 1M connected to the water supply pipe 1C and the hot water supply pipe 1H and forming a mixed water path through which mixed water, which is a mixture of water supplied from the water supply path and hot water supplied from the hot water supply path, flows. The hot water mixer 10 also includes a flow rate control valve 4C that controls the flow rate of water in the water supply path, and a temperature sensor 3C and a flow rate sensor 5C that detect the temperature and flow rate of water in the water supply path. The hot water mixer 10 also includes a flow rate control valve 4H that controls the flow rate of hot water in the hot water path, and a temperature sensor 3H and a flow rate sensor 5H that detect the temperature and flow rate of hot water in the hot water path. The hot and cold water mixing device 10 also includes a setting unit 70 that sets the temperature and flow rate of the mixed water in the mixing water channel, and a control unit 80 that controls the flow rate adjustment valves 4C and 4H. M and set flow rate Q M , the temperature T of the water in the water supply line obtained from the temperature sensor 3C C , the temperature T of the hot water in the hot water supply line obtained from the temperature sensor 3H H Based on this, the target flow rate Q of the flow control valve 4C is C1 , and the target flow rate Q of the flow control valve 4H H1 Calculate the target flow rate Q C1 ,Q H1 Based on this, the adjustment amount of the flow rate adjustment valves 4C, 4H is determined and controlled. In this way, the hot and cold water mixing device 10 can supply mixed water at a temperature and flow rate desired by the user.

[0027] The control unit 80 of the hot and cold water mixing device 10 compares the cold water side opening degree VPc, which indicates the degree to which the cold water side flow control valve 4C opens the water supply passage, with the hot water side opening degree VPh, which indicates the degree to which the hot water side flow control valve 4H opens the hot water supply passage. C ,Q H Based on this, the target flow rate Q C1 ,Q H1Calculate and update the updated target flow rate Q C1 ,Q H1 The flow rate control valves 4C and 4H on the smaller opening side are controlled based on the flow rate VPc and VPh on the larger opening side. Here, the flow rate control valve on the larger opening side may take longer to reach the target opening than the flow rate control valve on the smaller opening side. However, the hot water / water mixing device 10 controls the flow rate Q on the larger opening side VPc and VPh. C ,Q H Based on this, the target flow rate Q C1 ,Q H1 By calculating the temperature of the mixed water in the mixing channel, it is possible to prevent the temperature of the mixed water from becoming too high or too low instantaneously. Therefore, the hot and cold water mixing device 10 can perform stable temperature control without using a constant flow valve that detects pressure fluctuations.

[0028] Specifically, the control unit 80 of the hot and cold water mixing device 10 compares the cold water side opening degree VPc of the flow rate control valve 4C with the hot water side opening degree VPh of the flow rate control valve 4H, and when it determines that the cold water side opening degree VPc is greater than the hot water side opening degree VPh, the flow rate Q acquired by the cold water side flow rate sensor 5C is C Based on this, the target flow rate Q of the hot water side flow control valve 4H is set. H1 Calculate and update the updated target flow rate Q H1 The hot water flow control valve 4H is controlled based on the above. This controls the hot water flow rate Q H is the flow rate of water in the water supply channel Q C The temperature of the mixed water in the mixing channel does not suddenly increase or decrease compared to the hot water mixing device 10, and the temperature of the mixed water in the mixing channel does not suddenly change to the high or low temperature side. Therefore, the hot water mixing device 10 can perform stable temperature control.

[0029] In addition, the control unit 80 of the hot and cold water mixing device 10 compares the cold water side opening degree VPc of the flow rate control valve 4C with the hot water side opening degree VPh of the flow rate control valve 4H, and when it determines that the cold water side opening degree VPc is smaller than the hot water side opening degree VPh, it H Based on this, the target flow rate Q of the water side flow control valve 4C is set. C1 Calculate and update the updated target flow rate Q C1The water flow control valve 4C is controlled based on the above. This controls the flow rate Q of the water in the water supply line. C is the flow rate of hot water in the hot water supply passage Q H The temperature of the mixed water in the mixing channel does not suddenly increase or decrease compared to the hot water mixing device 10, and the temperature of the mixed water in the mixing channel does not suddenly change to the high or low temperature side. Therefore, the hot water mixing device 10 can perform stable temperature control.

[0030] The present disclosure is not limited to the embodiments described above and illustrated in the drawings, and the following embodiments are also included within the technical scope of the invention. (1) In the present embodiment, the hot and cold water mixing device 10 has an on-off valve 6M in the mixing pipe 1M, but the mixing pipe 1M does not have to have an on-off valve. In this case, the water supply pipe 1C and the hot water supply pipe 1H may have on-off valves, or the flow rate control valves 4C and 4H of the water supply pipe 1C and the hot water supply pipe 1H may have a function of closing each flow path as on-off valves. (2) In this embodiment, the water supply pipe 1C and the hot water supply pipe 1H have the flow rate sensors 5C and 5H, but one of the flow rate sensors 5C and 5H may be omitted, and the mixing pipe 1M may have the flow rate sensor. For example, if the hot water supply pipe 1H does not have the flow rate sensor 5H, the flow rate Q of the hot water in the hot water supply passage is H is the flow rate of the mixed water detected by the flow sensor in the mixing pipe 1M, and the flow rate Q of the water detected by the flow sensor 5C in the water supply pipe 1C. C It is calculated by subtracting (3) In the present embodiment, the control unit 80 is connected to the flow sensors 5C and 5H, the setting unit 70, and the like by wires. However, the control unit 80 may be electrically connected to some or all of these components wirelessly. (4) In the present embodiment, the setting unit 70 and control unit 80 have been described as setting and controlling the temperature and flow rate of the mixed water. However, various other controls may also be performed, such as draining hot water that has accumulated in the hot water supply path and cooled down, or automatically stopping the water supply after discharging mixed water at the set flow rate. [Explanation of symbols]

[0031] 10...Hot water mixing device, 1C...Water supply pipe (water supply channel), 1H...Hot water supply channel (hot water supply channel), 1M...Mixing pipe (mixing water channel), 3C...Temperature sensor (part of water side information acquisition section), 3H...Temperature sensor (part of hot water side information acquisition section), 4C...Flow rate control valve (water side flow rate control section), 4H...Flow rate control valve (hot water side flow rate control section), 5C...Flow rate sensor (part of water side information acquisition section), 5H...Flow rate sensor (part of hot water side information acquisition section), 70...Setting section, 80...Control section, C...Water supply source, H...Hot water supply source, Q M …Set flow rate (part of the setting information), T M …Set temperature (part of the setting information), Q C …Flow rate of water in the water supply channel (part of water information), T C …Temperature of water in the water supply channel (part of water information), Q H …The flow rate of hot water in the hot water supply line (part of the hot water information), T H …Temperature of the hot water in the hot water supply line (part of hot water information), Q C1 …the target flow rate of water into the water supply channel, Q H1 …Target flow rate of hot water in the hot water supply passage, VPc…Water side opening, VPh…Hot water side opening

Claims

[Claim 1] a water supply channel connected to a water supply source and through which water supplied from the water supply source flows; A hot water supply path connected to a hot water supply source through which hot water supplied from the hot water supply source flows; A mixed water channel connected to the water supply channel and the hot water supply channel, through which mixed water obtained by mixing water supplied from the water supply channel and hot water supplied from the hot water supply channel flows; A water flow rate regulator that regulates the flow rate of water in the water supply passage; A hot water flow rate adjusting unit that adjusts the flow rate of hot water in the hot water supply path; A water side information acquisition unit that acquires water information including a temperature and a flow rate of the water in the water supply line; A hot water side information acquisition unit that acquires hot water information including a temperature and a flow rate of the hot water in the hot water supply path; A setting unit for setting a temperature and a flow rate of the mixed water in the mixing water channel; A control unit that calculates a target flow rate of the water side flow rate adjustment unit and a target flow rate of the hot water side flow rate adjustment unit based on the setting information of the setting unit, the water temperature of the water side information acquisition unit, and the hot water temperature of the hot water side information acquisition unit, and controls the water side flow rate adjustment unit and the hot water side flow rate adjustment unit, The control unit compares the water side opening, which indicates the amount by which the water side flow rate adjustment unit opens the water supply passage, with the hot water side opening, which indicates the amount by which the hot water side flow rate adjustment unit opens the hot water passage, and calculates and updates the target flow rate of the flow rate adjustment unit for either the water supply passage or the hot water passage which has the smaller opening based on the flow rate acquired by the information acquisition unit for either the water supply passage or the hot water passage which has the larger opening between the water side opening and the hot water side opening, and controls the flow rate adjustment unit for the side with the smaller opening based on the updated target flow rate of the flow rate adjustment unit for the side with the smaller opening.

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