JP2007003131A - Hot water circulation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve accuracy of water flow detection in a hot water circulation passage, and to accurately carry out condition grasping in the hot water circulation passage in a hot water circulation system. <P>SOLUTION: By providing an ultrasonic flow velocity meter 6 in the hot water circulation passage, calculating a circulation flow rate in the hot water circulation passage and a sound velocity in the hot water circulation passage from a measured amount from the ultrasonic flow velocity meter 6 by a control means 12, and carrying out various types of operation control based on the calculated circulation flow rate and sound velocity, the water flow detection in the hot water circulation passage and the condition grasping in the hot water circulation passage can be carried out accurately. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention has a heat exchanging unit that supplies combustion heat and electric heat to warm water, and in the warm water circulation device that heats warm water by conveying warm water by a warm water circulation pump, an ultrasonic flow velocity in the warm water circulation channel through which warm water flows This technology relates to the technology that calculates the circulation flow rate of the hot water flowing through the hot water circulation channel and the speed of sound in the hot water circulation channel from the measured quantity with the ultrasonic current meter, and controls the operation based on these circulation flow rate and sound velocity. It is.

  First, the configuration of a conventional ultrasonic velocimeter will be described.

  Conventionally, this type of ultrasonic anemometer has two sets of transmitter and receiver facing each other in parallel with the fluid flow direction, one from upstream to downstream of the flow, and the other from downstream to upstream of the flow. Ultrasonic waves are sent toward and detected by a receiver. If the transmitter and receiver are placed in parallel with the fluid flow direction and the flow is hindered, the transmitter and receiver are placed on the flow path wall, and the upstream and downstream sides are arranged. It may be arranged with a certain angle. These ultrasonic velocimeters measure the measurement time difference and obtain the flow velocity, but are affected by the value of sound velocity, that is, the temperature value.

  As an ultrasonic anemometer that is not affected by the speed of sound, in the transmission / reception system arranged on the upstream and downstream sides of the flow, the propagation time from the upstream side to the downstream side and the propagation time from the downstream side to the upstream side There is a method for obtaining a flow velocity (see, for example, Patent Document 1). This method is called a sing-around method.

FIG. 3 shows the measurement principle of the conventional ultrasonic velocimeter described in Patent Document 1. In FIG. 3, it is assumed that the fluid in the flow path flows from the right side to the left side at a flow velocity U. An upstream ultrasonic transducer is arranged at a distance L and an angle θ on the upstream side of the flow channel, and a downstream ultrasonic transducer is arranged on the downstream side of the flow channel. The upstream ultrasonic transducer behaves as the transmitting side and the downstream ultrasonic transducer as the receiving side, ultrasonic waves are emitted from the upstream side to the downstream side, and the propagation time of the propagation distance L is assumed to be t ₁ . Acts as an upstream side ultrasonic transducers downstream ultrasonic transducers sender to the receiver, ultrasonic upstream side is emitted from the downstream side to the propagation time of the propagation distance L and t _2. When the speed of sound and A, _{t 1} and _{t 2} is expressed by the following equation.

t ₁ = L / (A + U cos θ) (1)
t ₂ = L / (A−U cos θ) (2)
If the sound velocity A is eliminated from the equations (1) and (2), the flow velocity U is obtained as in the equation (3).

U = (L / 2 cos θ) (1 / t ₁ −1 / t ₂ ) (3)
The flow rate of the fluid can be expressed by multiplying the flow velocity U calculated by the equation (3) by the channel area. Further, when the flow velocity U is eliminated from the equations (1) and (2), the sound velocity A is obtained as the equation (4).

A = (L / 2) (1 / t ₁ + 1 / t ₂ ) (4)
Next, a conventional hot water circulation device will be described. As a hot water circulation device, for example, consider a forced circulation type gas bath that transports bathtub water with a hot water circulation pump and heats it with combustion heat obtained by burning fuel gas such as city gas to replenish the bathtub water. Here, the forced circulation type refers to a system that has a hot water circulation pump inside the device and forcibly circulates the hot water, and is divided into a natural convection type in which hot water circulates by generating convection from given heat. Separated.

  FIG. 4 shows a basic configuration diagram of a conventional forced circulation gas bath.

  In FIG. 4, a conventional forced circulation type gas bath has a combustion fan 1 for supplying air, a gas governor valve 2 for adjusting the supply amount of fuel gas, a fuel gas injection nozzle 3 for supplying fuel gas, and the fuel. A combustion burner 4 for burning the fuel gas supplied from the gas injection nozzle 3 with the air supplied by the combustion fan 1, and a heat exchanging unit 5 for heating the hot water with the combustion heat generated by the combustion burner 4. The hot water circulation pump 7 for circulating the bathtub water 19 in the bathtub 18, the hot water flow path 8 through which the hot water heated by the heat exchange section 5 flows, and the heat exchange section are heated and heated. A warm water return passage 9 through which the warm water before flowing, a warm water return thermistor 10 for measuring the temperature of the warm water heated in the heat exchange section 5 provided in the warm water delivery channel 8, and the warm water return channel Returned to 9 A hot water return thermistor 11 for measuring the temperature of the hot water, a water flow switch 31 for detecting the water flow of the hot water flowing in the hot water circulation channel, and a control means 12 for controlling various operations. . Here, it is assumed that the hot water circulation pump 7 is an AC drive type having a constant output value.

  The forced circulation gas bath is connected to the warm water return pipe 15 at the warm water return pipe connection port 13 and to the warm water return pipe 16 at the warm water return pipe connection port 14. The hot water return pipe 15 and the hot water return pipe 16 are connected to a bathtub 18 by a bath adapter 17.

  The bath reheating operation of the conventional forced circulation gas bath having the above-described configuration will be described below.

  When the user sets the bath reheating temperature (for example, 40 ° C.) of the bath water 19 with an external input means such as a remote controller and the control means 12 is input to start the bath reheating operation, the control means 12 The pump 7 is driven. By the hot water circulation pump 7, the bathtub water 19 in the bathtub 18 flows to the heat exchange unit 5 through the hot water return pipe 16 and the hot water return channel 9. The water flow detection in the hot water circulation channel is determined by the water flow switch 31 provided in the hot water circulation channel. FIG. 4 shows a configuration in which the water flow switch 31 is provided in the hot water return flow path 9.

  As the water flow switch 31, for example, a butterfly-shaped configuration is conceivable. A magnet having a predetermined weight is attached to the butterfly portion, and when the water flow in the hot water circulation channel becomes a predetermined flow rate (for example, 3 L / min) or more, the butterfly portion is lifted to cause an electric communication state. It can be detected that a water flow is generated in the circulation channel. Further, if the water flow in the hot water circulation channel becomes a predetermined flow rate (for example, 2 L / min) or less, it is possible to detect that the butterfly portion cannot be lifted and no water flow is generated. FIG. 4 schematically shows a water flow detection presence / absence state of the water flow switch 31. That is, in the state of the broken line, no water flow is generated and the water flow switch 31 is in the OFF state. In the solid line state, the water flow is generated, the butterfly portion is lifted and the water flow switch 31 is in the ON state. Yes.

  When the hot water circulation pump 7 is driven and the water flow switch 31 detects the ON state, the control means 12 detects that a water flow is generated in the hot water circulation flow path and starts combustion. The combustion control at this time is performed as follows, for example.

The control means 12 starts combustion at a maximum combustion amount output value Q _max (for example, 7500 kcal / h) as a device. If the circulation flow rate is, for example, 10 L / min, and the temperature of the bath water 19 detected by the hot water return thermistor 11 at the start of combustion is 20 ° C., the hot water return temperature detected by the hot water return thermistor 10 at the start of combustion is
20+ (7500/60/10) = 32.5 ° C.
However, when the heating of the bathtub water 19 proceeds and the hot water going temperature detected by the hot water going thermistor 10 reaches a certain value (for example, “bath reheating set temperature (40 ° C. here)” + 3 ° C.) The control means 12 performs combustion control so that the temperature detected by the hot water going-up thermistor 10 becomes a predetermined value (here, 43 ° C.). That is, combustion control is performed such that the combustion amount is gradually reduced from the maximum combustion amount output value Q _max as the device to the minimum combustion amount output value Q _min (for example, 3500 kcal / h) as the device. When the combustion amount reaches the minimum combustion amount output value Q _min (for example, 3500 kcal / h) as the device, the control means 12 performs fixed combustion at the minimum combustion amount output value Q _min as the device. When the hot water return temperature, which is the temperature of the bathtub water 19 detected by the hot water return thermistor 11 in the process of performing such combustion control, reaches the bath reheating set temperature (40 ° C. in this case), the bath reheating operation is finished. To do.

  Next, as a conventional hot water circulation device, a bath with a gas water heater capable of pouring a predetermined amount of hot water into a bathtub in addition to the function of a forced circulation type gas bath that retreats bathtub water will be considered. There are two types of bath hot water systems for gas kettles with gas water heaters: a water volume system that counts a predetermined amount of water and heats it, and a water level system that detects the water level of the bathtub water and heats it up to a predetermined water level. Now consider the latter water level equation.

  FIG. 5 shows a configuration diagram of a conventional water bath with a water level type gas water heater.

  In FIG. 5, the difference from the configuration of the gas bath pot of FIG. 4 is that a hot water supply function for supplying hot water to a currant or a shower and the hot water supply function are used in addition to a bath reheating operation function for retreating the bathtub water 19. A bath hot water function for adding hot water at a predetermined water level to the bathtub 18 has been added. FIG. 5 shows a configuration of a one-can two-water heat exchanger in which two water pipes of a hot water supply side water pipe and a bath reheating side water pipe are arranged in one heat exchange unit can body. 5 has a hot water return channel 9 and a water level sensor 32 for detecting the water level of the bathtub water 19 and a hot water supply channel to the hot water circulation channel side. When the hot water supply side channel closed at the time of the bath reheating operation is overheated in the hot water recirculation channel side when the hot water supply valve 33 that is opened and closed at the time is opened and closed, the overpressure is released. There is a relief valve 34, a hot water supply valve 33 having a hot water supply side flow path and a hot water circulation flow path, and a hot water flow path 35 through which hot water flows from the hot water supply side flow path during pouring, and a combustion portion of the combustion burner 4. A switching solenoid valve 36 for opening and closing a fuel gas supply portion for switching, a water inlet passage 37 through which water supplied into the apparatus flows, and a temperature of water flowing through the water inlet passage 37 are detected. An incoming water thermistor 38, a water flow sensor 39 for detecting the incoming water flow rate, A hot water supply bypass control valve 40 for controlling the amount of water supplied into the apparatus and the hot water exiting the heat exchange section 5, and a hot water supply bypass having the hot water supply bypass control valve 40 and branching from the incoming water flow path 37. A flow path 41, a hot water supply side heat exchange section outlet thermistor 42 for detecting the temperature of hot water flowing on the hot water supply side after exiting the heat exchange section 5, and the hot water exiting the heat exchange section 5 and the hot water supply bypass flow path The hot water thermistor 43 for detecting the temperature of hot water mixed with the water flowing through 41, the hot water after leaving the heat exchanging section 5 and the hot water after mixed with the water flowing through the hot water supply bypass passage 41 are It comprises a flowing hot water flow path 44 and a water amount control valve 45 for controlling the hot water supply flow rate. Other configurations are the same as in the case of the forced circulation gas bath shown in FIG.

  Each operation of the conventional bath with a gas water heater configured as described above will be described below.

  First, a hot water supply operation for supplying hot water at a set temperature to a currant or a shower will be described with reference to FIG.

When a user sets the temperature of hot water (for example, 40 ° C.) with a remote controller or the like and opens a hot water tap such as a curan, combustion on the hot water supply side starts. For example, when the water flow to the hot water supply side channel is detected by a water flow sensor 39 provided in the incoming water flow channel 37 at a predetermined flow rate (for example, 2.5 L / min) or more, it can be determined that the water flow has occurred in the hot water supply side channel. Here, the water flow sensor 39 may have a configuration in which an impeller is provided in the flow path and the rotation of the impeller generated by the water flow is extracted as a pulse signal corresponding to the flow rate. The control means 12 calculates the flow rate flowing through the heat exchange unit 5 from the relationship between the incoming water flow rate detected by the water flow sensor 39 and the opening degree of the hot water supply bypass control valve 40, and detects the incoming water temperature detected by the incoming water thermistor 38. Combustion amount control is performed so that the temperature of the hot water after exiting the heat exchange unit 5 detected by the hot water supply side heat exchange unit outlet thermistor 42 becomes a predetermined temperature (for example, 60 ° C.). And the valve opening degree of the hot water supply bypass control valve 40 is adjusted so that the temperature of hot water detected by the hot water thermistor 43 becomes the temperature of hot water set by the user (for example, 40 ° C.). In this way, in the hot water supply operation, the control means 12 performs the combustion amount control and the valve opening adjustment of the hot water supply bypass control valve 40, and the hot water temperature detected by the hot water thermistor 43 is set to a temperature set by the user (for example, 40 ° C. ) Is controlled. Here, in the combustion control, the fuel gas supply amount is adjusted by adjusting the valve opening degree of the gas governor valve 2 as in the case of the conventional forced circulation gas bath shown in FIG. The combustion part is performed by opening and closing the switching electromagnetic valve 36 and opening and closing the fuel gas supplied to the combustion burner 4. As a configuration of the hot water supply bypass control valve 40, for example, a configuration in which the stepping motor is driven and the valve opening degree is adjusted in accordance with the drive pulse signal from the control means 12 is conceivable.

  Next, a bath hot water operation in which hot water of a predetermined level is poured into the bathtub 18 will be described with reference to FIG.

  The user enters the hot water temperature (eg, 40 ° C.) and the set water level (eg, “6” out of the water level setting range “1” to “10”) and starts bath hot water operation. Then, the control means 12 opens the pouring valve 33 and a water flow is generated in the pouring flow channel 35, whereby a water flow is generated in the hot water supply side flow channel, and the same operation as the above-described hot water supply operation is performed. The hot water flow path 35 is connected to the hot water return flow path 9, and hot water supplied in the hot water supply operation is branched in two directions as indicated by arrows in FIG. That is, one flows through the hot water return flow path 9 and the hot water return pipe 16 and is poured into the bathtub 18, and the other flows through the hot water return flow path 9, the heat exchange unit 5, the warm water return flow path 8, and the warm water return pipe 15. Hot water is poured into the bathtub 18. Here, in the hot water supply operation during the bath hot water operation, the control means 12 is such that the pouring temperature detected by the hot water thermistor 43 is a predetermined temperature (for example, 40 ° C.) than the hot water temperature (for example, 40 ° C.) set by the user. Operation control is performed so that the temperature is lower by 2 ° C.) (38 ° C. in this case). This is because one hot water branched from the pouring channel 35 is heated when it flows through the heat exchanging section 5 again. In the case of the water level type, the control means 12 drives the hot water circulation pump 7 to turn the water flow switch 31 ON and OFF every time when a predetermined amount of pouring is performed based on the incoming water flow rate detected by the water flow sensor 39. After performing the circulating water check operation to be confirmed, the hot water circulation pump 7 is stopped, waits for a predetermined time (for example, 30 seconds), and the water level of the bathtub water 19 is stabilized, and the water level sensor 32 confirms the water level of the bathtub water 19 While pouring until the water level set by the user is reached. When the hot water is poured to the water level set by the user, the control means 12 performs the bath reheating operation in the same manner as in the case of the forced circulation gas bath described above, and takes the bath to the temperature set by the user (for example, 40 ° C.). A chasing operation is performed, and the bath / hot water operation ends.

  The predetermined waiting time until the water level detection value of the water level sensor 39 after the above circulating water check operation is stabilized is the installation condition of the bathtub with the gas water heater, the bathtub 18, the bath outlet pipe 15, and the bath return pipe 16. Set for each. In general, the longer the pipe length of the bath outlet pipe 15 and the bath return pipe 16, the longer it takes to stabilize the water flow in the pipe. Therefore, for example, if the pipe length of the bath outlet pipe 15 and the bath return pipe 16 is equal to or longer than a predetermined length (for example, 15 m) at the time of equipment installation, a construction switch or the like is provided with a switch such as a dip switch provided in the control means 12. If the setting of the pipe length “long” is selected, the stabilization wait time when the water level sensor 39 detects the water level can be set long (for example, 90 seconds).

FIG. 5 shows the configuration of a water kettle with a water level type gas water heater, and the bath hot water operation in the bath kettle with a water level type gas water heater has been described above. However, the bath return pipe 9 has a water level sensor 32. In the bathtub with water-type gas water heater that counts the amount of pouring from the flow rate detected by the water amount sensor 39 and pours a predetermined amount of hot water into the bathtub 18, the bath water 19 exists in the bathtub 18. In the case of performing hot water bath operation, it is necessary to perform a “remaining hot water calculation” operation for calculating the amount of bathtub water 19 present in the bathtub 18. Assuming that the amount of bath water 19 in the bathtub 18 is calculated to be, for example, 80 L by this remaining hot water calculation, if the amount of pouring water set by the user is, for example, 180 L, the control means 12 will allocate the remaining 100 L. The amount of hot water is counted by the water amount sensor 39 and the bath hot water operation is performed. This remaining hot water calculation is performed as follows, for example.

  In the remaining hot water calculation, the bath water 19 in the bathtub 18 is bathed up to a predetermined temperature rise, the total amount of heat obtained by the circulating hot water during that time is calculated, and the total heat amount is divided by the predetermined temperature rise. By doing.

  Assuming that the amount of remaining hot water in the bathtub water 19 in the bathtub 18 is V (L) and the predetermined temperature rise is ΔTc (K), the amount of heat Q (() obtained by the temperature rise of the remaining hot water V (L) by ΔTc (K) kcal) can be expressed by equation (5). Since the temperature of the bath water 19 can be detected by the hot water return thermistor 11, a predetermined temperature rise ΔTc (K) can be measured by monitoring the temperature rise from the bath water temperature at the start of the remaining hot water calculation. . Here, the predetermined temperature rise ΔTc (K) has a value of about 3K, for example.

Q = VΔTc (5)
On the other hand, the control means 12 measures a temperature difference ΔTi (K) between the warm water return temperature detected by the warm water return thermistor 10 and the warm water return temperature detected by the warm water return thermistor 11 at every predetermined time interval Δt (min). To do. Here, ΔTi (K) is a temperature difference between the warm water return temperature detected by the warm water return thermistor 10 and the warm water return temperature detected by the warm water return thermistor 11 at the time iΔt (min) after the remaining hot water calculation is started. To express. The predetermined time interval Δt (min) is a value such as about 0.1 min. Assuming that the learning value of the circulating flow during the trial operation performed at the time of equipment installation is q _learning (L / min), the amount of heat Qi (kcal) obtained by the circulating hot water at the time interval Δt (min) at time iΔt (min) is (6) It can be expressed by an expression.

Qi = q _learning ΔtΔTi (6)
Here, the circulation flow rate learning operation at the time of trial installation performed at the time of equipment installation is performed with the temperature of the warm water thermistor 10 and the warm water return thermistor 11 in a state where the control means 12 maintains a predetermined combustion amount output value (for example, 4800 kcal / h). This is done by measuring the difference. At this time, if the temperature difference between the warm water return thermistor 10 and the warm water return thermistor 11 is 10K, for example, the circulation flow rate is 4800/60/10 = 8 L / min.
It is calculated that

  The control means 12 is calculated by the equation (6) as shown by the equation (7) until the remaining hot water amount V (L) of the bathtub water 19 in the bathtub 18 reaches a predetermined temperature rise ΔTc (K). The amount of remaining hot water V (L) in the bathtub water 19 in the bathtub 18 reaches a predetermined temperature rise ΔTc (K) by adding the amount of heat Qi (kcal) obtained from the circulating hot water to i during Δt (min) The total amount of heat Q (kcal) obtained by circulating hot water is calculated.

Q = ΣQi = q _learning Δt (ΣΔTi) (7)
When equations (5) and (7) are placed equally and solved for V, the remaining hot water amount V (L) can be expressed as equation (8).

V = {q _learning Δt (ΣΔTi)} / ΔTc (8)
JP-A-8-122117

  However, in the conventional forced circulation type gas bath and the bath with a gas water heater, only the presence or absence of water flow can be determined by the water flow switch 31, and the circulation flow rate of the hot water circulation channel cannot be measured. There was a problem that the state in the flow channel could not be determined in detail. For example, as an example of a problem in which the state in the hot water circulation channel cannot be determined in detail, when the user performs a bath chasing operation during bathing, the user clogs a towel or the like from the bath adapter 17 portion, and the circulation flow rate As long as the water flow switch 31 is ON, an abnormal state such as clogging in the hot water circulation channel cannot be detected. In the same case, there is a case where a girl with long hair is drawn into the bath adapter and cannot escape from that state, leading to drowning. In addition, the water flow switch 31 has a problem in that the predetermined flow rate at which the water flow is detected varies due to variations in the weight of the magnet and component variations such as the magnetic force of the magnet.

  Further, in a water bath with a water level type gas water heater, there is a problem in that it takes time to set a stabilization waiting time for the water level detection value of the water level sensor 39 depending on the length of the bath outlet pipe 15 and the bath return pipe 16. There was also.

  Also, in a water bath with a water-type gas water heater, it is necessary to perform a circulating flow learning operation during a trial run when installing the equipment, because the circulating flow in the hot water circulation channel cannot be measured when calculating the remaining hot water. There was also a problem.

  The present invention solves the above-described conventional problem, and includes an ultrasonic velocity meter in a hot water circulation channel through which hot water flows, and a circulating flow rate of hot water flowing through the hot water circulation channel from a measurement amount by the ultrasonic velocity meter, It is an object of the present invention to provide a hot water circulation device that calculates the speed of sound in the hot water circulation channel and that is controlled in operation based on the circulation flow rate and the sound speed.

  In order to solve the above-mentioned conventional problems, the hot water circulation device of the present invention includes an ultrasonic current meter in a warm water circulation channel through which hot water flows, and hot water flowing through the hot water circulation channel from a measurement amount of the ultrasonic current meter. The circulation flow rate and the sound velocity in the hot water circulation channel are calculated, and the operation control based on the circulation flow rate and the sound velocity is performed.

  Thereby, it is possible to perform operation control based on the circulation flow rate and the sound velocity, and to grasp the state in the hot water circulation channel based on the circulation flow rate and the sound velocity.

  The hot water circulation device of the present invention includes an ultrasonic velocity meter in the hot water circulation channel through which the hot water flows, and the circulating flow rate of the hot water flowing through the hot water circulation channel and the sound velocity in the hot water circulation channel from the measurement amount of the ultrasonic velocity meter. And more detailed operation control can be realized based on the circulating flow rate and the sound speed.

  In the first invention, an ultrasonic current meter is provided in the hot water circulation flow path, and the control means calculates the circulation flow rate of the hot water circulation flow path from the measured amount. The control means performs various operations based on the calculated circulation flow rate. Operation control can be performed.

  In particular, the second invention circulates from the measured amount of the ultrasonic current meter in the hot water return channel by providing the ultrasonic current meter of the first invention in the hot water return channel of the hot water circulation channel. The calculation of the flow rate is performed by the control means, and the control means can control various operations based on the calculated circulation flow rate.

  In particular, the third invention circulates from the measured amount of the ultrasonic current meter in the hot water flow channel by providing the ultrasonic current meter of the first invention in the warm water flow channel of the hot water circulation channel. The calculation of the flow rate is performed by the control means, and the control means can control various operations based on the calculated circulation flow rate.

  In the fourth aspect of the invention, in particular, in the control means of any one of the first to third aspects, the state in the hot water circulation channel is grasped based on the circulation flow rate calculated from the measurement amount from the ultrasonic current meter. By providing the function to perform, the control means can grasp the state in the hot water circulation channel in detail.

  According to a fifth aspect of the invention, in particular, in the hot water circulation apparatus according to any one of the first to fourth aspects of the invention, the control means calculates the speed of sound in the hot water circulation flow path from the measured amount from the ultrasonic current meter, and the control means Can control various operations based on the calculated sound speed.

  The sixth aspect of the invention is, in particular, in the control means of the fifth aspect of the invention, by providing a function of grasping the state in the hot water circulation channel based on the speed of sound calculated from the measurement amount from the ultrasonic current meter, The control means can grasp the state in the hot water circulation channel in detail.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
In this embodiment, instead of the water flow detection function of the water flow switch 31 of the forced circulation type gas bath as a conventional hot water circulation device or a bath with a gas water heater, corresponding to the first to third inventions, The operation control for detecting the water flow from the calculation of the circulation flow rate based on the measurement amount from the ultrasonic anemometer will be described.

  FIG. 1 shows a configuration diagram of a forced circulation gas bath in the first to sixth embodiments.

1 differs from the configuration diagram of the conventional forced circulation gas bath shown in FIG. 4 in that the ultrasonic anemometer 6 shown in FIG. 3 is arranged instead of the water flow switch 31 shown in FIG. The control means 12 is provided with a function for calculating the circulation flow rate and the sound speed from the propagation time t ₁ and the propagation time t ₂ which are measured quantities from the ultrasonic current meter 6 and controlling the operation based on the circulation flow rate and the sound speed. is there.

  Moreover, FIG. 2 shows the block diagram of the bathtub with a gas water heater in Embodiment of 1st-6th invention.

2 differs from the configuration diagram of the conventional bath with a gas water heater shown in FIG. 5 in that the forced circulation gas bath in the first to sixth embodiments of the present invention shown in FIG. Similarly to the configuration of the conventional forced circulation gas bath shown in FIG. 4, the ultrasonic current meter 6 shown in FIG. 3 is arranged in place of the water flow switch 31 shown in FIG. The control means 12 is provided with a function of calculating the circulation flow rate and the sound speed from the propagation time t ₁ and the propagation time t ₂ which are measurement amounts from the ultrasonic current meter 6 and controlling the operation based on the circulation flow rate and the sound speed. By the way.

1 and 2 is arranged in the hot water return flow path 9 in the second invention, the hot water flow path 8 in the third invention. The effect is the same even if the ultrasonic velocimeter 6 is arranged inside. In all the following embodiments, as shown in FIGS. 1 and 2, the ultrasonic velocimeter 6 will be described in a configuration in which it is arranged in the hot water return flow path 9 in the hot water circulation flow path. And

  The operation and action of the forced circulation gas bath having the above-described configuration and the bath with a gas water heater will be described below.

1 and 2, an ultrasonic current meter 6 is provided in the hot water circulation channel, and the control means 12 calculates the circulation flow rate from the propagation time t ₁ and the propagation time t ₂ that are measured quantities from the ultrasonic current meter 6. By doing so, it can be set as the function instead of the water flow detection function of the conventional water flow switch 31 shown in FIG. 4 and FIG. That is, at the time of bathing operation, the control means 12 drives the hot water circulation pump 7 to calculate the circulation flow rate, and when a predetermined circulation flow rate (for example, 3 L / min) or more is detected, a water flow is generated in the hot water circulation channel. Control the operation to detect this. Here, the circulation flow rate q can be calculated as in equation (9) using equation (3), where S is the cross-sectional area of the hot water circulation channel.

q = SU = S (L / 2 cos θ) (1 / t ₁ −1 / t ₂ ) (9)
As described above, in the present embodiment, the ultrasonic velocity meter 6 is provided in the hot water circulation channel, and the control unit 12 determines the propagation time t ₁ and the propagation time t ₂ that are the measurement amounts from the ultrasonic velocity meter 6. By calculating the circulation flow rate according to the equation (9), it can be an alternative function of the water flow detection function of the conventional water flow switch 31. As a result, water flow detection based on the circulation flow rate q can be performed, so that water flow detection variations due to component variations of the water flow switch 31 of the conventional hot water circulation device can be eliminated.

(Embodiment 2)
In the present embodiment, whether or not the bath adapter 17 is submerged in the bath water 19 in a forced circulation gas bath or a hot water bath with a gas water heater as a conventional hot water circulation device corresponding to the fourth invention. Next, the operation control performed by the circulation flow rate calculation based on the measurement amount from the ultrasonic velocity meter 6 will be described.

In a forced circulation gas bath with a conventional hot water circulation device or a bath with a gas water heater, the control means 12 first drives the hot water circulation pump 7 to detect the water flow switch 31 when performing a bath reheating operation. For example, the state of whether or not the bath adapter 17 is submerged in the bathtub water 19 is determined as follows from the signal.
<State 1> When the water flow switch 31 is OFF for a predetermined time (for example, 60 seconds) The bath adapter 17 is not submerged in the bath water 19 at all.
<State 2> When the water flow switch 31 repeats ON / OFF for a predetermined time (for example, 60 seconds) The bath adapter 17 is not completely submerged in the bath water 19.
<State 3> When the water flow switch 31 is ON for a predetermined time (for example, 60 seconds) The bath adapter 17 is completely submerged in the bath water 19.

  Here, only in the case of <state 3> where the bath adapter 17 is completely submerged in the bathtub water 19, the control means 12 can continue the bath reheating operation. In the case of <State 1> or <State 2>, for example, in the conventional forced circulation gas bath, the bath adapter 17 cannot be continued in the bath water 19 because the bath adapter 17 is not submerged. The user has been informed of the content of adding the bath water until the bath adapter 17 is completely submerged in the bath water 19. In the case of <state 1> or <state 2>, for example, in a conventional bath with a gas water heater, the hot water valve 33 is opened until the bath adapter 17 is completely submerged in the bath water 19 to add bath water. Such operation control was performed.

Further, in the conventional water flow switch 31, even when <state 3> is detected, if the magnet weight of the water flow switch 31 is light due to variations in the components of the water flow switch 31, for example, the bath adapter 17 is completely removed from the bath water 19 Even if it is not submerged, it may be detected when it is completely submerged.

  Therefore, in the present embodiment, an ultrasonic velocity meter 6 is provided in the hot water circulation channel, and the bath adapter 17 is supplied to the bathtub water 19 based on the circulation flow rate calculated from the measurement amount from the ultrasonic velocity meter 6. A method of detecting a submerged state with higher accuracy than in the case of the conventional water flow switch 31 will be described.

First, the control means 12 stores the circulating flow maximum value q _max in a range of a predetermined circulating flow rate (for example, 3 L / min) or more when the hot water circulation pump 7 is driven and the bath reheating operation is normally performed. Q _max is learned that the bath adapter 17 is completely submerged in the bath water 19. Here, the maximum circulation flow rate q _max should always show the same value as long as the conveying capacity of the hot water circulation pump 7 and the installation conditions of the equipment, the bathtub 18, the bath outlet pipe 15, and the bath return pipe 16 are the same. For example, it can be updated at any time, including the effects of aging and measurement errors.

Next, the control means 12 compares the circulating flow rate q calculated by the bath reheating operation (9) with the stored circulating flow rate maximum value q _{max in} the forced circulation type gas bath shown in FIG. For example, the following operation control is performed to detect the submerged state of the bath adapter 17 in the bath water 19.
<Case 1> q is 0.95q _max or less The control means 12 detects a state in which the bath adapter 17 is not submerged in the bath water 19, stops the driving of the hot water circulation pump 7, and allows the user to make an amount of the bath water 19 Informs the user that the bath is not sufficient for the chasing operation and prompts the user to add bathtub water 19.
<Case 2>q> 0.95q _max
The control means 12 detects the state in which the bath adapter 17 is completely submerged in the bath water 19 and performs the bath chasing operation as it is.

As described above, in the present embodiment, the ultrasonic velocity meter 6 is provided in the hot water circulation channel, and the control unit 12 determines the propagation time t ₁ and the propagation time t ₂ that are the measurement amounts from the ultrasonic velocity meter 6. By grasping the state in the hot water circulation channel based on the circulation flow rate calculated by the equation (9), the bath adapter 17 can be supplied to the bathtub water 19 more accurately than the water flow detection using the conventional water flow switch 31. A submerged state can be detected.

(Embodiment 3)
In the present embodiment, in response to the fourth invention, in a forced circulation type gas bath as a hot water circulation device or a bath with a gas water heater, when a user is performing a bath retreat operation during bathing In addition, a clogged state in which towel or hair is accidentally sucked into the bath adapter 17 is detected by grasping the state in the hot water circulation channel using the circulation flow rate calculated by the measurement amount from the ultrasonic current meter 6. The operation control will be described.

In this case, in FIG. 1 and FIG. 2, the control means 12 calculates the circulating flow rate calculated value within a predetermined time (for example, 30 seconds) from the circulating flow rate calculated value based on the measurement amount from the ultrasonic velocimeter 6 during the bath chasing operation. Monitor the amount of change. When the bath reheating operation is normally performed without any problem, the circulation flow rate calculation value q is substantially the same as the circulation flow rate maximum value q _max described in the second embodiment (for example, 0.95q _max <q < 1.05q _max ). Here, when towel or hair is sucked in the bath adapter 17, the hot water circulation channel is closed as a result, and the circulation flow rate calculation value q decreases. For example, the controller 12 recognizes this state as the next clogging detection condition.
<Clogging detection conditions>
Within a predetermined time (for example, 30 seconds), the circulation flow rate calculation value q continues for a predetermined time (for example, 5 seconds). A predetermined ratio (for example, 0.8q corresponding to 80% of q _max ) of the circulation flow rate maximum value q _max If it changes suddenly to less than _max ), it is detected as a clogged hot water circulation channel.

  When the clogging is detected, the control means 12 stops the bath chasing operation and performs operation control such as generating an alarm sound to notify the surroundings.

As described above, in the present embodiment, the ultrasonic velocity meter 6 is provided in the hot water circulation channel, and the control unit 12 determines the propagation time t ₁ and the propagation time t ₂ that are the measurement amounts from the ultrasonic velocity meter 6. The clogged state in the hot water circulation channel can be detected by monitoring the circulation flow rate calculated by the equation (9). This makes it possible to detect a state in which a towel or hair has been accidentally sucked into the bath adapter 17 when the user is chasing the bath while taking a bath, thereby ensuring the safety of the user. .

(Embodiment 4)
In this embodiment, corresponding to the fifth and sixth inventions, the submerged state in the bath water 19 of the bath adapter 17 of the above-described second embodiment is determined by the measurement amount from the ultrasonic current meter 6 (4). The operation control detected by grasping the state in the hot water circulation channel by the sound speed A calculated from the equation will be described.

The speed of sound is greater in liquid than in gas and in liquid. For example, at 0 ° C., it is about 330 m / s in air but about 1400 m / s in water. Sound velocity greatly influenced by the temperature, but ignored when the air and water order sound velocity considering the 10 ¹ different, the effect of temperature be about determining the submerged state to bath water 19 bath Adapter 17 However, there is no problem in actual use. In FIG. 1 and FIG. 2, if the bath adapter 17 in <State 2> of the second embodiment is not completely submerged in the bath water 19, air is present in the hot water circulation channel. Therefore, the sound velocity should be lower than that in the case of <State 3> where the hot water circulation passage is completely filled with hot water. Therefore, for example, the control unit 12 detects the submerged state of the bath adapter 17 in the bath water 19 similar to that of the above-described second embodiment according to the following conditions, and performs operation control.
<Case 1> The speed of sound A is 1300 m / s or less The control means 12 detects a state in which the bath adapter 17 is not submerged in the bath water 19, stops driving the hot water circulation pump 7, and allows the user to make an amount of the bath water 19. Informs the user that the bath is not sufficient for the chasing operation and prompts the user to add bathtub water 19.
<Case 2> Sound velocity A> 1300 m / s
The control means 12 detects the state in which the bath adapter 17 is completely submerged in the bath water 19 and performs the bath chasing operation as it is.

As described above, in the present embodiment, the ultrasonic velocity meter 6 is provided in the hot water circulation channel, and the control unit 12 determines the propagation time t ₁ and the propagation time t ₂ that are the measurement amounts from the ultrasonic velocity meter 6. By substituting the state in the hot water circulation channel based on the speed of sound calculated by the equation (4), the bath adapter 17 is submerged in the bathtub water 19 with higher accuracy than the conventional water flow detection using the water flow switch 31. The state can be detected.

(Embodiment 5)
In the present embodiment, corresponding to the fifth and sixth inventions, the sound velocity A calculated from the equation (4) based on the measurement amount from the ultrasonic current meter 6 and the circulating flow rate calculated from the equation (9). The case where the state in the hot water circulation channel is grasped by using both q and various operations are controlled will be described.

When the hot water circulation pump 7 is driven at the time of bathing operation or the like, the circulation flow rate q is substantially the value of the maximum circulation flow rate q _max (for example, q> 0.9q _max ), but the sound speed A is implemented as described above. In the case of 1300 m / s or less in Form 4, it is considered that a pipe connection failure or a pipe breakage occurs in the middle of the pipe, and air is caught in the hot water circulation channel system. In such a case, for example, the control means 12 detects an abnormal piping state and performs operation control to notify the user of the state.

  In addition, in the case where clogging occurs in the hot water circulation flow path in correspondence with the above-described third embodiment, in addition to the conditions that cause a sudden decrease in the circulation flow rate as described in <clogging detection conditions> in the third embodiment, When the sonic velocity A> 1300 m / s is satisfied at the same time, it is possible to detect a state in which the hot water circulation channel is clogged.

  As described above, in the present embodiment, the ultrasonic velocity meter 6 is provided in the hot water circulation channel, and the sound velocity A calculated from the equation (4) by the measurement amount from the ultrasonic velocity meter 6 is obtained. By using both of the circulation flow rate q calculated from the equation, it is possible to grasp the state in the hot water circulation flow path, and it is possible to detect the abnormal piping state and more detailed clogging detection than in the case of the third embodiment. .

(Embodiment 6)
In the present embodiment, the sound speed A when the hot water circulation channel in the above-described fourth and fifth embodiments is filled with warm water corresponding to the fifth and sixth inventions is determined for each warm water temperature. This section describes how to control various operations by learning and learning the state of the hot water circulation flow path with higher accuracy in consideration of the hot water temperature.

The learning of the sonic speed A for each hot water temperature is performed, for example, under the condition that the hot water circulation channel is filled with hot water (for example, 0.95q _max <q <1.05q _max ) when performing a bath chasing operation. It is considered that every time the hot water temperature changes by 1 ° C., the sound speed value at that time is learned. Here, the hot water temperature can be detected by the hot water return thermistor 11 in FIGS. The control means 12 learns the sound speed A under the condition that the hot water circulation channel at the hot water temperature T ° C. thus obtained is filled with hot water as a function A (T) of the hot water temperature T ° C.

  Alternatively, at the time of a trial run performed at the time of equipment installation, the bath adapter 17 is completely submerged in the bath water 19 and the hot water circulation channel is filled with the hot water, and the hot water circulation operation is performed. For example, the sound speed A at six locations (30 ° C., 34 ° C., 38 ° C., 42 ° C., 46 ° C., 50 ° C.) is measured, and the control means 12 is based on these measured sound speeds A, for example, the least square method. The sound speed A at the hot water temperature T ° C is learned as a function A (T) of the hot water temperature T ° C.

In this way, using the speed of sound A as the function A (T) of the hot water temperature T ° C., the submerged state of the bath adapter 17 in the bathtub water 19 in the above-described fourth embodiment is accurate under the following conditions, for example. Can be determined.
<Case 1> The speed of sound A calculated at the hot water temperature T ° C. is 0.95 A (T) or less. The control means 12 detects a state where the bath adapter 17 is not submerged in the bath water 19 and drives the hot water circulation pump 7. Is stopped, and the user is informed of the fact that the amount of bathtub water 19 is insufficient to perform the bath chasing operation, and urges the user to add bathtub water 19.
<Case 2> The speed of sound A calculated at the hot water temperature T ° C is A> 0.95A (T)
The control means 12 detects the state in which the bath adapter 17 is completely submerged in the bath water 19 and performs the bath chasing operation as it is.

Further, using the speed of sound A as the function A (T) of the hot water temperature T ° C. and corresponding to the fifth embodiment, the circulation flow rate is obtained when the hot water circulation pump 7 is driven, such as during a bath reheating operation. q is approximately the value of the maximum circulation flow rate q _max (for example, q> 0.9q _max ), but when the sonic velocity A calculated at the hot water temperature T ° C. is 0.95 A (T) or less, the hot water circulation channel system It is possible to detect an abnormal piping condition by recognizing that the air is stuck in the air.

  Similarly, when the sound velocity A as the function A (T) of the hot water temperature T ° C. is used to correspond to the above-described fifth embodiment, it is abrupt as described in <clogging detection condition> in the third embodiment. When the condition of sonic velocity A> 0.95 A (T) is satisfied at the same time in addition to the condition where the circulating flow rate is reduced, it is possible to detect a state where the hot water circulation channel is clogged.

  As described above, in the present embodiment, while the hot water temperature is measured by the hot water return thermistor 11, the control means 12 controls various operations using the learned sound speed A as the function A (T) of the hot water temperature T ° C. Therefore, various operation controls can be performed with higher accuracy than in the fourth and fifth embodiments.

(Embodiment 7)
In the present embodiment, the water level detection value stabilization wait time of the water level sensor 32 during the bath hot water operation in the water bath with a water level type gas water heater shown in FIG. 2 corresponding to the first to third inventions. A case where operation control is performed based on the circulation flow rate calculated from the measurement amount from the ultrasonic current meter 6 will be described.

  As in the background art described above, in a water bath with a water level type gas water heater, the control means 12 in FIG. 5 each time a predetermined amount of hot water is poured based on the flow rate detected by the water flow sensor 39, the hot water circulation pump 7 is driven and the water flow switch 31 is operated to check the ON / OFF operation, and then the hot water circulation pump 7 is stopped to stabilize the water level of the bath water 19 for a predetermined time (for example, 30 seconds). The water pouring operation is performed until the water level set by the user is reached while the water level sensor 32 confirms the water level of the bathtub water 19. Here, for the circulating water check operation by the water flow switch 31, for example, a method of determining the water flow from the circulating flow rate calculated as in the first embodiment can be applied. In the present embodiment, after the hot water circulation pump 7 is stopped, the water level detection value stabilization waiting time of the water level sensor 32 is determined based on the circulation flow rate calculated from the measurement amount from the ultrasonic velocimeter 6. Describe how to do it.

The circulation flow rate is greatly influenced by the installation conditions of the length of the hot water return pipe 15 and the hot water return pipe 16 and the number of bends in the middle of the pipe, and if the pipe length is long or the number of bends in the middle of the pipe increases, the flow resistance will increase. Increasing the circulating flow rate decreases. Therefore, in FIG. 2, the smaller the circulating flow rate calculated from the measured amount from the ultrasonic anemometer 6, the larger the pipe flow resistance, that is, the longer pipe or the more bent the pipe is. Since it takes time until the warm water flow in the warm water circulation flow path is stabilized, it is necessary to set the water level detection value stabilization waiting time of the water level sensor 32 to be long. Therefore, the control means 12 performs operation control during bath hot water operation, for example, based on the following circulation flow rate conditions.
<Condition 1> When q (provided that 0.95q _max <q <1.05q _max ) calculated at the time of circulating water check is less than 5 L / min, the water level sensor detection value stabilization wait time is 90 seconds.
<Condition 2> When q (provided that 0.95q _max <q <1.05q _max ) calculated during the circulating water check is 5 L / min or more and less than 8 L / min, the water level sensor detection value stabilization waiting time is 60 Seconds.
<Condition 3> When q (provided that 0.95q _max <q <1.05q _max ) calculated at the time of circulating water check is 8 L / min or more, the water level sensor detection value stabilization wait time is 30 seconds.

Alternatively, as shown in the following formula (10), the water level sensor detection value stabilization waiting time is determined as a function of q (provided that 0.95q _max <q <1.05q _max ) calculated during the circulating water check. Is also possible. However, in Formula (10), q shall be 3 L / min or more.

(Water level sensor detection value stabilization wait time in seconds) = − 10q + 140 (10)
As described above, in the present embodiment, the water level detection value stabilization waiting time of the water level sensor 32 is calculated from the measured amount from the ultrasonic anemometer 6 at the time of bath hot water operation in a bath with a water level type gas water heater. In the conventional bath with a gas water heater shown in FIG. 5, the control performed by the contractor when installing the equipment according to the length of the bath outlet pipe 15 and the bath return pipe 16 in the conventional bath with gas water heater shown in FIG. The trouble of setting the pipe length “long” with a changeover switch such as a dip switch provided in the means 12 can be saved.

(Embodiment 8)
In the present embodiment, the water level detection value stable state of the water level sensor 32 is exceeded during the bath hot water operation in the bath with water level type gas water heater shown in FIG. 2, corresponding to the first to fourth inventions. The operation control determined from the circulating flow rate calculated from the measured amount from the sonic anemometer 6 will be described.

  In the seventh embodiment, the hot water circulating pump 7 is operated based on the flow rate calculation value at the time of circulating water check by driving the hot water circulation pump 7 and based on the water level detection value stabilization waiting time of the water level sensor 32 assuming the channel resistance. In the present embodiment, after the circulating water check by driving the hot water circulation pump 7, in this embodiment, the circulation flow rate in the hot water circulation channel from the time when the driving of the hot water circulation pump 7 is stopped is calculated, The flow state of the hot water in the hot water circulation channel is determined from the calculated circulation flow rate. That is, even if the drive of the hot water circulation pump 7 is stopped after the circulating water check, the hot water in the hot water circulation channel flows due to inertia for a while, but the hot water flow is attenuated and the circulation flow rate calculation value q Is within a predetermined value range (for example, −0.5 L / min <q <0.5 L / min), the control means 12 converges the hot water flow in the hot water circulation channel and detects the water level of the water level sensor 32. Performs operation control that captures values.

  As described above, in the present embodiment, the water level detection value stable state of the water level sensor 32 is calculated from the measurement amount from the ultrasonic anemometer 6 during the bath hot water operation in the bath with a water level type gas water heater. Since the determination is based on the circulation flow rate, the water level detection value of the water level sensor 32 can be taken in more simply and accurately than in the case of the seventh embodiment.

(Embodiment 9)
In the present embodiment, the water level detection value stable state of the water level sensor 32 is exceeded at the time of bath hot water operation in the bath with water level type gas water heater shown in FIG. 2 corresponding to the fifth to sixth inventions. The operation control determined from the circulation flow rate calculated from the measurement amount from the sonic velocimeter 6 and the sound velocity will be described.

  When air is caught in the hot water circulation channel, if the air mass is present in the water pressure detection portion of the water level sensor 32, the water level sensor 32 cannot correctly detect the water level of the bathtub water 19. Therefore, in the present embodiment, in addition to taking in the water level detection value of the water level sensor 32 from the attenuated state of the circulating flow after driving of the hot water circulation pump 7 described in the eighth embodiment, the sound speed calculation at the time of circulating water check is performed. Operation control is performed to confirm that there is no air bite in the hot water circulation channel from the value. Here, for example, the sound speed A (T) at the temperature T ° C. detected by the hot water return thermistor 11 as in the sixth embodiment is applied to the sound speed calculation value at the time of circulating water check.

As described above, in the present embodiment, the water level detection value stable state of the water level sensor 32 is calculated from the measurement amount from the ultrasonic anemometer 6 during the bath hot water operation in the bath with a water level type gas water heater. In addition to determining from the circulating flow rate, in order to perform operation control for confirming the presence or absence of air biting that affects the water level detection value of the water level sensor 32 at the time of circulating water check, the operation control is performed compared to the case of the eighth embodiment. The water level detection value of the water level sensor 32 can be taken in more accurately.

(Embodiment 10)
In the present embodiment, the circulation calculated from the ultrasonic anemometer to the circulation flow rate used in the remaining hot water calculation of the background art described above in the water tank with a water-type gas water heater corresponding to the first to third inventions. A method using the flow rate will be described.

  In the present invention, for example, as shown in FIG. 2, the circulating flow rate can be calculated from the amount measured by the ultrasonic velocimeter 6 provided in the hot water circulation channel, and the remaining hot water calculation described in the background art is performed using this circulating flow rate. It can be performed.

  As described above, in the present embodiment, since the circulation flow rate can be calculated from the amount measured by the ultrasonic velocimeter 6 provided in the hot water circulation flow path, this is performed at the time of equipment installation in the conventional bath with water-type gas water heater. Circulating flow rate learning operation at the time of trial operation can be made unnecessary.

  As described above, the hot water circulation device according to the present invention is provided with the ultrasonic current meter 6 in the hot water circulation channel, and the circulating flow rate of the hot water flowing through the hot water circulation channel or the sound velocity in the hot water circulation channel is measured. Can be calculated, and the operation control based on the circulation flow rate and the speed of sound and the state in the hot water circulation channel can be grasped. Therefore, if the technique of the present invention is applied, it can be used for analysis in a channel in a channel through which a fluid accompanied by a phase change flows. For example, in the case of a gas-liquid two-phase flow, it is considered possible to calculate the void ratio representing the gas existing ratio in the flow path from measuring the speed of sound.

Configuration diagram of forced circulation type gas bath in Embodiments 1 to 6 of the present invention The block diagram of the bathtub with a gas water heater in Embodiment 1-10 of this invention Illustration of the measurement principle of an ultrasonic current meter Configuration diagram of a conventional forced circulation gas bath Configuration diagram of a conventional bathtub with a gas water heater

Explanation of symbols

5 Heat Exchanger 6 Ultrasonic Current Meter 7 Hot Water Circulation Pump 8 Warm Water Outflow Channel 9 Hot Water Return Channel 12 Control Means

Claims (6)

A heat exchanging part for exchanging heat, a hot water circulation pump for circulating hot water, a hot water return channel through which hot water flowing into the heat exchanging unit flows as a hot water circulating channel, and the heat exchanging unit as a hot water circulating channel The warm water flow path through which the hot water after receiving the heat flows, the ultrasonic flow velocity meter provided in the warm water circulation flow channel, and the circulating flow rate of the warm water passing through the warm water circulation flow channel from the measurement amount of the ultrasonic flow velocity meter And a control means for controlling various operations based on the circulation flow rate. The hot water circulation apparatus according to claim 1, wherein an ultrasonic current meter is provided in the hot water return flow path. The hot water circulation device according to claim 1, wherein an ultrasonic current meter is configured to be provided in the warm water outgoing flow path. The hot water circulation device according to any one of claims 1 to 3, wherein the control means has a function of grasping a state in the hot water circulation channel based on the calculated circulation flow rate. 5. The control device according to claim 1, wherein the control unit has a function of calculating a sound velocity in the hot water circulation channel from a measurement amount of the ultrasonic current meter and controlling various operations based on the sound velocity. Hot water circulation device. The hot water circulation device according to claim 5, wherein the control means has a function of grasping a state in the hot water circulation channel based on the calculated sound speed.