JP3713223B2 - Hot water heater - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hot water heating apparatus, and more particularly to a control technology for a circulation pump used in a circulation circuit of a hot water heating apparatus.
[0002]
[Prior art]
FIG. 6 shows a schematic configuration of a hot water circulation circuit in a conventional hot water heating apparatus. In the example shown in the figure, a heater (hot terminal) that receives a relatively hot water supply such as a bathroom dryer or a panel heater and a relatively low temperature hot water such as a floor heating panel for a single water heater (hot water heat source). A hot water heating apparatus to which a hot water terminal apparatus of high and low temperature of a heater (low temperature terminal) to be supplied is connected is shown.
[0003]
Specifically, in this hot water heating apparatus, high temperature hot water (high temperature water) heated by the heat exchanger a of the water heater is returned to the heat exchanger a through the high temperature terminal b, the expansion tank d, and the circulation pump e. The circulating water and the warm water (cold water) branched on the upstream side of the heat exchanger a (specifically, the downstream side of the circulation pump e) are returned to the expansion tank d and the circulation pump e via the low temperature terminal c. And a circulation circuit that circulates.
[0004]
On the other hand, each hot water terminal device (high temperature terminal b, low temperature terminal c) is provided with a thermal valve f as shown in the figure as an incoming water control means, and the hot water terminal device (high temperature terminal b, low temperature terminal c). Is operated, by opening the thermal valve f, hot water is supplied to each terminal heat exchanger g.
[0005]
And in the hot water heating apparatus comprised in this way, the AC pump driven with an alternating current power supply is widely used until now as the said circulation pump e, and the number (system number) of the hot water terminal devices to drive | operate The AC pump has been driven at a constant rotational speed regardless of whether or not recently, the control unit h of the water heater changes the rotational speed of the AC pump according to the number of operating hot water terminal devices to be operated. There has also been proposed a hot water heater configured as described above.
[0006]
[Problems to be solved by the invention]
However, such a conventional hot water heater has the following problems and has been desired to be improved.
[0007]
(1) That is, in this type of hot water heater, an AC pump is used as a circulation pump as described above, and in most cases, the rotation speed of the circulation pump is a constant rotation speed. The sensor for detecting the rotation speed of the circulation pump was not provided. Therefore, despite the fact that the hot water terminal device has started operation and the circulating pump has been driven, there has been a situation in which the rotation of the pump is locked due to dust biting or the like, or the rotation does not reach the target rotational speed. However, such a situation could not be detected.
[0008]
(2) Further, in this type of hot water heating apparatus, a water level detecting means for detecting the level of the expansion tank is provided. However, when such a water level detecting means fails and a decrease in the water level cannot be detected, the circulating water is detected. Even though there is no hot water in the circuit, the circulating pump will run idle, and the circulating pump will rotate at an extremely high rotational speed. The same applies when electrical noise is applied to the harness. In such a case, since the conventional hot water heating apparatus does not detect the rotation speed of the circulation pump, there is a problem that the discovery is delayed.
[0009]
(3) In addition, recent hot water terminal devices have been proposed that suppress noise generated from equipment by temporarily reducing the capacity of the hot water heat source device by operation on the hot water heat source device side. However, in the conventional hot water heating apparatus, since the rotation speed of the circulation pump is constant, the noise caused by the circulation pump does not change, so that the noise suppression effect is not so high.
[0010]
The present invention has been proposed in view of such conventional problems, and a main object thereof is to provide a hot water heating apparatus that can easily detect a failure of a circulating pump of hot water heating.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, a hot water heating apparatus according to the present invention includes a hot water heat source device that supplies hot water and a plurality of hot water terminal devices connected by a circulation circuit having a circulation pump, and a control means is the hot water terminal. In the hot water heating apparatus that sets a target rotational speed of the circulating pump according to the operating state of the apparatus and gives a speed command signal to the circulating pump based on the target rotational speed, the control means includes hot water in the circulating circuit When executing the control for increasing the flow rate, the control for gradually increasing the rotational speed of the circulating pump toward the set target rotational speed is executed while the control for decreasing the hot water flow rate in the circulating circuit is executed. when is provided with a control arrangement for executing control of lowering the rotation speed of the circulation pump instantaneously toward the target rotational speed, the rotational speed for detecting the rotational speed to the circulation pump Means out, characterized by comprising a failure determination means for performing a failure determination of the circulation pump on the basis of the detection result of said rotational speed detecting means.
[0012]
As a preferred embodiment of the hot water heating apparatus having such a configuration, the failure determination means is detected by the rotation speed detection means when at least one of the hot water terminal devices is in operation. And a control structure for determining that the circulation pump is faulty when the rotation speed of the circulation pump does not reach a predetermined rotation speed set in advance. Further, as a modification thereof, the failure determination means has a control configuration for determining that the failure of the circulation pump when a state in which the rotation speed of the circulation pump does not reach the predetermined rotation speed continues for a predetermined time. To do.
[0013]
As another preferred embodiment, the failure determination means is configured to detect the rotation speed of the circulation pump detected by the rotation speed detection means when at least one of the hot water terminal devices is operating. Is characterized in that it has a control configuration for determining that the circulation pump is faulty when it exceeds a predetermined number of revolutions set in advance.
[0014]
Furthermore, as another preferred embodiment, the failure determination means is configured such that the rotation speed of the circulating pump detected by the rotation speed detection means when at least one of the hot water terminal devices is operating. When the speed does not reach the target rotational speed, the speed command signal is compared with a predetermined value, and if the speed command signal exceeds the predetermined value, it is determined that the circulation pump is faulty. It is characterized by that. As a modified example, when it is determined in the above determination that the circulation pump is faulty, the control means has a control configuration that lowers the target rotation speed of the circulation pump by a predetermined rotation speed. .
[0015]
Then, hot-water heating apparatus according to the present invention, a structure for suppressing the generated noise, before Symbol control means to have a variable controlling constituting the target rotational speed in accordance with the operating conditions of the hot heat source device Features.
[0016]
In these hot water heaters, a DC pump driven by a DC power source is used as the circulation pump.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a hot-water heating apparatus according to the present invention will be described in detail with reference to FIGS. 1-5. FIG. 1 shows an example of a schematic configuration of a hot water heating apparatus according to the present invention. This hot water heating apparatus is a hot water heating apparatus having hot and cold two-temperature hot water terminal devices as in the conventional hot water heating apparatus described above. A hot water supply device 1 serving as a hot water heat source, a hot water terminal device (high temperature terminal) 2 that receives high-temperature hot water supply from the hot water supply device 1 through a circulation circuit described later, and a hot water terminal device that receives low-temperature hot water supply (Low temperature terminal) 3 as a main component. Moreover, in the example of illustration, the said low temperature terminal device 3 is comprised by 3 units | sets (3 systems) shown with code | symbol 3a-3b.
[0018]
FIG. 2 shows an example of a hot water circulation circuit in the hot water heating apparatus. That is, this hot water heating apparatus is similar to the above-described conventional hot water heating apparatus. The heat exchanger 11 of the water heater 1 and the high and low temperature hot water terminal apparatus that receives the supply of hot water heated by the heat exchanger 11. The hot water circulation circuit is formed by connecting the (high temperature terminal 2, low temperature terminal 3), the expansion tank 4, and the circulation pump 5 as shown in the figure.
[0019]
The water heater 1 is a device that serves as a heat source for the hot water supplied to the hot water terminal device (the high temperature terminal 2 and the low temperature terminal 3), and the water heater 1 has a conventionally known configuration such as a gas water heater. A device is used. The water heater 1 includes a burner (not shown) and a control unit (control means) 8 that controls the circulation pump 5. The circulation pump 5 is electrically connected to the control unit 8. A speed command signal V _SP of a circulating pump 5 described later is given to the circulating pump 5 from the control unit 8.
[0020]
In addition, the control unit 8 is provided with bidirectional communication means 9 electrically connected to each hot water terminal device (high temperature terminal 2, low temperature terminal 3). Thus, bidirectional communication with each hot water terminal device (high temperature terminal 2, low temperature terminal 3) is possible.
[0021]
And this water heater 1 shown to this embodiment is equipped with the quiet mode (silent function) especially. Specifically, by a predetermined operation of the remote controller 12 connected to the water heater 1, the control unit 8 of the water heater 1 suppresses combustion of the burner, and noise generated with the combustion is below a predetermined level (for example, 40 dB). ) Is added.
[0022]
As described above, the hot water terminal device is composed of two types of heating devices, the high temperature terminal 2 and the low temperature terminal 3. The high-temperature terminal 2 is a heating device that receives a high-temperature (for example, 80 ° C.) hot water supply from the water heater 1, and includes a bathroom dryer, a panel heater, a hot-water air conditioner, and the like. The low-temperature terminal 3 is a heating device that receives a low-temperature (for example, 60 ° C.) hot water supply from the water heater 1 through the circulation circuit, and includes a floor heating panel or the like.
[0023]
Each of these hot water terminal devices (high temperature terminal 2 and low temperature terminal 3) includes a heat exchanger 7 as shown in FIG. 2, and controls the water entering the equipment upstream of each heat exchanger 7. A thermal valve 6 is provided. For example, when the high temperature terminal 2 is described as an example, the thermal valve 6 is configured to open when the operation start of the high temperature terminal 2 is instructed by an operation unit (not shown). . That is, it is configured to supply warm water to the heat exchanger 7 by opening the valve when the operation of the high temperature terminal 2 starts.
[0024]
Each of these hot water terminal devices (high temperature terminal 2, low temperature terminal 3) is provided with bidirectional communication means (not shown), and is provided in the control unit 8 of the water heater 1 by this bidirectional communication means. Bidirectional communication with the bidirectional communication means 9 is possible. That is, various setting operations (in the operation unit of the hot water terminal device (high temperature terminal 2, low temperature terminal 3)) performed by the two-way communication between the water heater 1 and the hot water terminal device (high temperature terminal 2, low temperature terminal 3) ( For example, an operation start / stop setting operation or a hot dash operation setting operation described later) can be transmitted to the control unit 8 of the water heater 1.
[0025]
The expansion tank 4 is a tank for replenishing water connected to a water supply (not shown), and includes a water level electrode (water level detecting means) for monitoring the water level in the tank and a water replenishing electromagnetic valve for controlling water supply to the tank. When the water level falls below a predetermined water level, the water supplement electromagnetic valve is automatically opened to supply water from the water supply.
[0026]
The circulation pump 5 has an impeller that forcibly circulates hot water in the circulation circuit, and is a pump means that supplies the hot water heated by the heat exchanger 11 to the high temperature terminal 2 and the low temperature terminal 3 by rotating the impeller. In the present invention, a DC pump (not shown) driven by a DC power source is used as the circulation pump 5.
[0027]
More specifically, the DC pump includes a motor that is PWM-controlled by the control unit 8 of the water heater 1, and the rotation speed of the fan is determined by a voltage (speed command signal) V _SP supplied from the control unit 8. Is arbitrarily set, and the flow rate (discharge pressure) of the hot water in the circulation circuit can be controlled by varying the rotation speed.
[0028]
In the hot water heating apparatus of the present invention, since a DC pump driven by a DC motor is adopted as the circulation pump 5, a rotation speed detection mechanism (rotation speed) (not shown) such as a Hall IC having a Hall element in the DC motor. Detection means) is provided, and the detection result is input to the control unit 8.
[0029]
In FIG. 2, reference numeral 10 denotes a bypass pipe provided for bypassing the circulation circuit.
[0030]
Next, operation | movement of the hot water heating apparatus comprised in this way is demonstrated based on FIG. 3 and FIG.
[0031]
That is, in the hot water heating apparatus of the present invention, when any one of the hot water terminal devices (the high temperature terminal 2 and the low temperature terminal 3) is started, the control unit 8 of the water heater 1 is connected via the bidirectional communication means 9. To that effect (see step S1 in FIG. 3).
[0032]
When the controller 8 detects the start of operation of the hot water terminal device (the high temperature terminal 2 and the low temperature terminal 3), the control unit 8 instructs the circulation pump 5 to rotate at a predetermined initial rotation speed (3000 rpm in the illustrated example). The command signal V _SP is output (see step S2 in FIG. 3), the operation state of the hot water terminal device (high temperature terminal 2, low temperature terminal 3) is determined, and the target rotational speed of the circulating pump 5 is set based on the result. (See step S3 in FIG. 3).
[0033]
Here, the operation state of the hot water terminal device (high temperature terminal 2, low temperature terminal 3) is previously patterned in several ways based on the number of operating high temperature terminals 2 and low temperature terminals 3. The target rotational speed is set in advance based on this operating state, and is determined based on a table stored in the control unit 8.
[0034]
Specifically, for example, as shown in FIG. 4, when the high temperature terminal 2 is stopped and only one of the low temperature terminals 3 (one system) is operating, the target rotational speed of the circulation pump 5 is When the high temperature terminal 2 is stopped and two of the low temperature terminals 3 (two systems) are operating, the target rotational speed of the circulation pump 5 is set to 3175 rpm. Further, when the high temperature terminal 2 is operating, the rotation speed of the circulation pump 5 is set to 3600 rpm regardless of whether the low temperature terminal 3 is operated or the number of the operation. Further, when the hot water heater 1 has a bathing function, the temperature is set to 3600 rpm during the bathing operation regardless of whether or not the high temperature terminal 2 or the low temperature terminal 3 is operated.
[0035]
When the target rotational speed of the circulation pump 5 is set based on such table information, the control unit 8 increases the rotational speed of the circulation pump 5 by a constant rotation every predetermined time (12 in the example of FIG. 4). A secondary target rotational speed that is increased by 50 rpm per second) is set, and the rotational speed of the circulation pump 5 is increased toward the target rotational speed.
[0036]
That is, for example, when the target rotational speed is 3175 rpm, the speed command signal V _SP for rotating the circulating pump 5 at the initial rotational speed (3000 rpm) is output, and then 12 seconds later, the rotational speed of the circulating pump 5 is increased by 50 rpm to 3050 rpm. The speed command signal V _SP is output. And, thereafter repeats the output of the speed command signal V _SP rotation speed of the circulation pump 5 until it reaches 3175rpm which is the target rotational speed, corresponding to the secondary target speed obtained by adding 50rpm to 12 second intervals.
[0037]
Here, the configuration that gradually increases the rotational speed of the circulation pump 5 as described above is that, as described above, the thermal valve 6 provided in the hot water terminal device (high temperature terminal 2, low temperature terminal 3) Even if the operation of the hot water terminal device (high temperature terminal 2, low temperature terminal 3) is started, it takes a certain time (for example, about 2 minutes) until it is completely opened. This is because the hot water flow rate in the circulation circuit is gradually increased according to the condition). In other words, the rapid increase of the hot water flow rate in the circulation circuit prevents the internal pressure in the circulation circuit from increasing rapidly, and the discharge pressure of the circulation pump 5 is adjusted according to the opening state of the thermal valve 6. It is for raising.
[0038]
Therefore, the process of gradually increasing the number of revolutions of the circulation pump 5 in this way is performed by either one unit (one system) from the state where the hot water terminal device (the high temperature terminal 2 or the low temperature terminal 3) is not operating at all as described above. This is also performed not only when the operation of) is started, but also when, for example, one of the low temperature terminals 3 is operated (one system) and the other one is additionally operated to form two systems. That is, if processing for increasing the number of revolutions of the circulation pump 5 based on the table information shown in FIG. 4 (control for increasing the flow rate of hot water in the circulation circuit) is required, processing similar to that described above is performed each time. Done.
[0039]
Similarly, the setting of the target rotational speed is newly updated every time the operating state of the hot water terminal device (high temperature terminal 2, low temperature terminal 3) changes. That is, for example, when the low temperature terminal 3 is operated with one (one system) and another one is additionally operated to have two systems, the target rotational speed is updated from 3175 rpm to 3500 rpm.
[0040]
In addition, by updating the target rotational speed in the control unit 8 in this way, the number of operating hot water terminal devices (high temperature terminal 2, low temperature terminal 3) is decreased, and the rotational speed of the circulation pump 5 is decreased. When processing (control to reduce the hot water flow rate in the circulation circuit) is required, the rotation of the circulation pump 5 toward the newly set target rotation speed is different from the case of increasing the rotation speed described above. A process for instantaneously lowering the number is performed. That is, in this case, the control unit 8 outputs a speed command signal V _SP corresponding to the new target rotational speed to the circulation pump 5.
[0041]
This is different from the case where the rotational speed of the circulation pump 5 is increased, and when the flow rate of the hot water in the circulation circuit decreases, the hot water terminal devices (the high temperature terminal 2 and the low temperature terminal 3) are damaged due to the internal pressure increase in the circulation circuit. It is because there is no fear of it.
[0042]
Thus, in the hot water heating device of the present invention, the target rotational speed of the circulation pump 5 is set according to the operating status of the hot water terminal device (high temperature terminal 2, low temperature terminal 3). Since the low temperature terminal 3) is always supplied with hot water having an amount of heat suitable for its operation, each hot water terminal device (high temperature terminal 2, low temperature terminal 3) may become overcapacity or fall short of capacity. And heating can be performed efficiently.
[0043]
In addition, when the control for increasing the hot water flow rate in the circulation circuit is performed, the rotational speed of the circulation pump 5 gradually increases, so that the hot water flow rate in the circulation circuit does not increase rapidly, and the internal pressure in the circulation circuit increases. It is possible to prevent damage to the circulation circuit and hot water terminal devices (high temperature terminal 2 and low temperature terminal 3) associated with.
[0044]
And in the hot water heating apparatus which concerns on this invention, since the water heater 1 is provided with the silence function as mentioned above, the target rotation speed shown in FIG. 4 mentioned above changes suitably according to the operation | movement condition of the water heater 1. FIG. Will be corrected.
[0045]
Specifically, when the silent mode is selected in the remote controller 12 of the water heater 1, the control unit 8 decreases the initially set target rotational speed by a predetermined rotational speed (uniformly 200 rpm in the illustrated example), and thereby circulates. The noise generated from the pump 5 is suppressed.
[0046]
Note that such target rotational speed variable correction processing is included in the table information of the control unit 8 in advance based on the function of the water heater 1. Therefore, for example, when the water heater 1 performs an operation that temporarily enhances combustion of the burner, the target rotational speed may be increased and corrected accordingly. In addition, for this purpose, the predetermined rotation speed (uniformly 200 rpm in the illustrated example) can be appropriately changed according to the function of the water heater 1.
[0047]
And in this invention, in the hot water heating apparatus comprised in this way, the said control part 8 functions as a failure diagnostic means which detects the failure of a circulation pump, and detects and judges the failure of a circulation pump as follows. To do.
[0048]
FIG. 5 is a flowchart showing an example of the failure detection and determination procedure. As shown in the figure, when any one of the hot water terminal devices (the high temperature terminal 2 and the low temperature terminal 3) starts operation (see step S1 in FIG. 5), first, as described above, the control unit 8 switches to the circulation pump 5. On the other hand, a speed command signal V _SP instructing rotation at a predetermined initial rotation speed (3000 rpm in the illustrated example) is output (see step S1 in FIG. 5).
[0049]
If there is no abnormality in the circulation pump 5, the number of rotations of the circulation pump 5 gradually increases toward the target number of rotations according to the above-described procedure. Does not rise as it did.
[0050]
Therefore, first, the control unit 8 determines whether or not the rotational speed of the circulation pump 5 detected by the rotational speed detection mechanism has reached a predetermined rotational speed (1000 rpm in the illustrated example), and this predetermined rotational speed. It is determined whether or not the number of states continues for a certain time (25 seconds in the illustrated example) (see step S3 in FIG. 5).
[0051]
This determination is a process for detecting whether or not the rotation of the circulation pump 5 is significantly hindered, such as when the rotation of the circulation pump 5 is locked due to dust biting or the like. When the rotation speed continues for 25 seconds or more and is 1000 rpm or less, it is determined that the rotation of the circulation pump 5 is significantly hindered, and the circulation pump 5 is stopped and combustion of the water heater 1 is stopped. (See step S4 in FIG. 5). At that time, a predetermined failure display (error display) is performed on a display unit (not shown) of the water heater 1 to notify the outside of the failure of the circulation pump 5.
[0052]
In step S3 in FIG. 5, it is determined whether or not the state of the predetermined rotation speed (1000 rpm) has continued for a certain time or longer. However, the operation of the hot water terminal device (high temperature terminal 2, low temperature terminal 3) is performed. When a certain amount of time has elapsed since the start, it may be determined that the rotation of the circulation pump is significantly hindered by not reaching a predetermined rotation speed.
[0053]
Further, the predetermined rotational speed may be set to a value that is somewhat lower than a preset initial rotational speed (3000 rpm in the illustrated example), and specific numerical values can be changed as appropriate. Similarly, the predetermined time can be appropriately changed.
[0054]
Then, as a result of the determination in step S3 in FIG. 5, when it is determined that the circulation pump 5 is rotating at a predetermined rotation speed or more, it can be determined that the circulation pump 5 is rotating for the time being. In step S5 in FIG. 5, it is determined whether the rotational speed of the circulation pump 5 is not abnormally high.
[0055]
That is, in step S5 of FIG. 5, the state in which the rotational speed of the circulation pump 5 detected by the rotational speed detection mechanism exceeds a predetermined rotational speed (5500 rpm in the illustrated example) exceeds a predetermined time (1 in the illustrated example). For example, when the flow rate of hot water in the circulation circuit decreases due to a decrease in the water level of the expansion tank 4 or when electrical noise enters the harness. Moreover, since the circulation pump 5 rotates excessively, the excessive rotation is detected.
[0056]
Therefore, when it is determined in step S5 in FIG. 5 that the state in which the rotational speed of the circulation pump 5 exceeds the predetermined rotational speed (5500 rpm in the illustrated example) continues for a predetermined time (1 minute in the illustrated example). Therefore, it is determined that the circulation pump 5 is rotating excessively, and the process proceeds to step S4 in FIG. 5 to stop the drive of the circulation pump 5 and to stop the combustion of the water heater 1.
[0057]
In the determination in step S5 in FIG. 5, the condition that the rotational speed of the circulation pump 5 continues for a predetermined time (in the case of 1 minute in the figure) is that the circulation is caused by a malfunction due to temporary electrical noise. This is to prevent the pump 5 from stopping, and the predetermined time can be appropriately changed within the range of this purpose. The predetermined number of rotations (5500 rpm in the illustrated example) can be changed as appropriate as long as the number of rotations is sufficient to determine whether or not the circulation pump 5 is rotating excessively.
[0058]
If a negative determination is made in step S5 in FIG. 5, the process in step S6 in FIG. 5 is then executed. The process of step S6 in FIG. 5 is a process when the rotation speed of the circulation pump 5 does not reach the target rotation speed due to dust biting of the circulation pump 5, and the speed command signal V _SP output from the control unit 8 and (in the illustrated case, the maximum value of the speed command signal V _SP) predetermined value to detect a failure of the circulation pump 5 by comparing the.
[0059]
That is, when the rotation speed of the circulation pump 5 does not reach the target speed, the process of trying to reach the rotation speed of the circulation pump 5 to the target rotational speed by increasing the speed command signal V _SP the controller 8 since performed, the rotation of the circulation pump 5 is inhibited by the dust chewing, etc., the speed command signal V _SP output from the control unit 8 to rise to eventually reach its maximum value.
[0060]
Therefore, in step S6 in FIG. 5, the speed command signal _VSP is monitored, and when the value reaches a predetermined value (the maximum value of the speed command signal _{VSP in} the illustrated example), the rotation of the circulation pump 5 is significantly increased. Although it is not inhibited, it is judged that it is inhibited to some extent by dust biting or the like.
[0061]
If the rotation of the circulation pump 5 is inhibited in this way, the process proceeds to step S7 in FIG. 5, and the initially set target rotational speed is set to a predetermined rotational speed (100 rpm in the illustrated example). Execute the lowering process. That is, by this, the speed command signal _VSP is lowered and the operation is continued, thereby preventing the power consumption of the circulation pump 5 from rising abnormally.
[0062]
On the other hand, if the speed command signal V _SP does not reach the predetermined value in the process of step S6 in FIG. 5, it is determined that the circulation pump 5 is operating without abnormality, and the process proceeds to step S3 in FIG. 5 is continuously monitored for abnormalities.
[0063]
The predetermined value used in FIG. 5 step S6 may be a value not used when the circulation pump 5 is normally driven, such as set to 90% of the speed command signal V _SP appropriate It can be changed. In addition, the predetermined rotation speed used in step S7 in FIG. 5 is not limited to the rotation speed illustrated, and can be changed as appropriate.
[0064]
As described above, in the hot water heating apparatus of the present invention, the control unit 8 also functions as a failure determination unit. The occurrence of various failures can be prevented in advance.
[0065]
The above-described embodiment is merely a preferred embodiment of the present invention, and the present invention is not limited to this, and various design changes can be made within the scope of the invention.
[0066]
For example, in the above-described embodiment, the configuration in which the target rotational speed of the circulation pump 5 is set based on the table information stored in the control unit 8 in advance is shown. However, the rotational speed of the circulation pump 5 is determined by two-way communication. You may comprise so that the said control part 8 may calculate each time based on the operating number etc. of the hot water terminal device (high temperature terminal 2, low temperature terminal 3) to acquire. Similarly, when the water heater 1 has an operation function different from a normal operation such as a silent function, a calculation program corresponding to the function is stored in the control unit 8 in advance and the calculation is performed thereby. Configured as follows.
[0067]
Further, in the above-described embodiment, when the rotation speed of the circulation pump 5 is increased, the rotation speed of the circulation pump 5 is increased by a constant rotation speed every predetermined time. However, the rotation speed of the circulation pump 5 is What is necessary is just to raise gradually according to the valve-opening condition of the thermal valve 6, for example, you may comprise so that rotation speed may be raised so that a gentle linear shape may be drawn.
[0068]
In the above-described embodiment, a case where a plurality of hot water terminal devices (high temperature terminal 2 and low temperature terminal 3) are provided is shown. However, the hot water heating device and the control method thereof according to the present invention have only one hot water terminal device. The present invention is also applicable to a case where it is not provided (for example, a case where only one low temperature terminal 3 is provided). In that case, when the operation is started in the hot water terminal device, the circulation pump 5 is configured such that the rotational speed gradually increases in accordance with the opening state of the thermal valve 6 included in the hot water terminal device. Moreover, when the said hot water terminal device has the special driving | operation form mentioned above, the target rotation speed of the circulation pump 5 is also corrected according to the driving | running form.
[0069]
Note that the table information and the increase pattern of the rotational speed of the circulation pump 5 shown in FIG. 4 described above are merely examples for carrying out the present invention, and specific numerical values can be changed as appropriate.
[0070]
【The invention's effect】
As described in detail above, according to the present invention, the hot water heat source device for supplying hot water and the plurality of hot water terminal devices are connected by the circulation circuit having the circulation pump, and the control means is the operating status of the hot water terminal device. In a hot water heating apparatus that sets a target rotational speed of the circulating pump according to the target rotational speed and gives a speed command signal to the circulating pump based on the target rotational speed, a rotational speed detecting means that detects the rotational speed of the circulating pump; Since the failure determination means for determining the failure of the circulation pump based on the detection result of the rotation speed detection means is provided, it is possible to prevent the circulation pump from being damaged due to the garbage of the circulation pump or the lack of water in the expansion tank. be able to.
[0071]
Further, hot-water heating device of the present invention, since the upper Symbol control means includes a variable control constituting the target rotational speed in accordance with the operating conditions of the hot heat source device, a hot water heat source device, for example a special such as silent function Even if a hot water heat source device having an operation function is used, the effect of such a function can be sufficiently exhibited.
[0072]
In addition, according to the present invention, a DC pump that can easily control the rotation speed is used as the circulation pump that constitutes the hot water heating apparatus. Therefore, when the rotation speed of the circulation pump is controlled, there is no increase in size. Can be replaced with a pump.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing an example of a schematic configuration of a hot water heating apparatus according to the present invention.
FIG. 2 is an explanatory diagram showing an example of a hot water circulation circuit in the hot water heating apparatus.
FIG. 3 is a flowchart showing an example of a control operation at the start of operation of the hot water heating apparatus in the hot water heating apparatus.
FIG. 4 is an explanatory diagram showing an example of table information of a control unit of the hot water heater.
FIG. 5 is a flowchart showing a procedure for determining a failure of the circulation pump in the hot water heating apparatus.
FIG. 6 is an explanatory diagram showing an example of a hot water circulation circuit in a conventional hot water heating apparatus.
[Explanation of symbols]
1 Water heater (hot water heat source machine)
2 High temperature terminal (warm water terminal device)
3,3a-3c Low temperature terminal (hot water terminal device)
4 Expansion tank 5 Circulation pump 6 Thermal valve 7 Terminal heat exchanger 8 Control unit (control means, failure judgment means)

Claims (8)

A hot water heat source device for supplying hot water and a plurality of hot water terminal devices are connected by a circulation circuit having a circulation pump, and a control means sets a target rotational speed of the circulation pump according to an operation state of the hot water terminal device. In the hot water heating apparatus that gives a speed command signal to the circulation pump based on the target rotational speed,
When executing the control to increase the hot water flow rate in the circulation circuit, the control means executes control to gradually increase the rotation speed of the circulation pump toward the set target rotation speed, When executing the control to reduce the hot water flow rate in the circuit, it has a control configuration for executing the control for instantaneously lowering the rotational speed of the circulation pump toward the target rotational speed,
Wherein the rotation speed detecting means, that become comprise <br/> and failure determining means for performing a failure determination of the circulation pump on the basis of the detection result of said rotational speed detecting means for detecting a rotational speed to the circulation pump Hot water heater. The failure determination means is configured such that when at least one of the hot water terminal devices is operating, the rotation speed of the circulation pump detected by the rotation speed detection means reaches a predetermined rotation speed set in advance. The hot water heating apparatus according to claim 1, further comprising: a control configuration that determines that a failure of the circulation pump occurs when the operation is not performed. The said failure determination means has a control structure which judges that it is a failure of a circulation pump when the state where the rotation speed of the said circulation pump does not reach the said predetermined rotation speed continues for a fixed time. Hot water heater. In the failure determination means, when at least one of the hot water terminal devices is in operation, the rotation speed of the circulating pump detected by the rotation speed detection means exceeds a preset predetermined rotation speed. The hot water heating apparatus according to claim 1, further comprising a control configuration that determines that the circulation pump is faulty. The failure determination means, when at least one of the hot water terminal devices is in operation, when the rotation speed of the circulation pump detected by the rotation speed detection means does not reach the target rotation speed, 2. The control structure according to claim 1, wherein the speed command signal is compared with a predetermined value, and when the speed command signal exceeds the predetermined value, it is determined that a circulation pump has failed. Hot water heating system. 6. The control structure according to claim 5, wherein when it is determined that the circulation pump has failed, the control means has a control structure for reducing the target rotation speed of the circulation pump by a predetermined rotation speed. Hot water heater. The control means has a control configuration in which the target rotational speed is variable in accordance with the operation state of the hot water heat source machine.
The hot water heating device according to any one of claims 1 to 6, wherein   The hot water heating apparatus according to any one of claims 1 to 7, wherein a DC pump driven by a direct current power source is used as the circulation pump.

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