JP2021183890A - Hot water supply system - Google Patents

Abstract

To provide a hot water supply system which can accurately detect when an abnormality occurs in instantaneous hot water operation.SOLUTION: A hot water supply system SY includes a control unit 6 which can execute abnormality determination processing, after starting of instantaneous hot water operation, for determining whether a hot water supply terminal 8 is in an opened state or not when a detection temperature of a temperature sensor Sa is not raised to a prescribed temperature or higher while an integrated flow rate of hot water detected with the usage of a flow rate sensor Sb reaches a prescribed value at which the detection temperature of the temperature sensor Sa is usually expected to be raised to the prescribed temperature or higher, and determining that an abnormality occurs in instantaneous hot water operation when the hot water supply terminal 8 is not in the opened state.SELECTED DRAWING: Figure 2

Description

The present invention relates to a hot water supply system capable of immediate hot water operation.

Here, "immediate hot water operation" in the present specification means that when the hot water supply terminal in the hot water supply system is opened, hot water water having a predetermined temperature or higher can be immediately discharged from the hot water supply terminal. This is an operation for circulating or retaining heated hot water of a predetermined temperature or higher in a hot water flow path connected to a hot water supply terminal.

As a hot water supply system, for example, as described in Patent Documents 1 to 3, there is a hot water supply system capable of immediate hot water operation.
Specifically, in this hot water supply system, hot water heated by using a heat exchanger can be supplied to a hot water tap via a hot water outlet. On the other hand, a return flow path provided with a pump is connected to the hot water flow path, and a hot water circulation path capable of circulating and circulating hot water through a fixed route is formed.
In a hot water supply system having such a configuration, when the hot water tap is closed and the hot water discharge from the hot water tap is stopped, the hot water heated by the heat exchanger is circulated in the hot water circulation path. , Or immediate hot water operation to stay is possible. If such an immediate hot water operation is executed, when the hot water tap is opened after that, hot water having a temperature higher than a predetermined temperature in the hot water circulation path is immediately discharged from the hot water tap, which is convenient. ..

However, in the above-mentioned conventional arts, there is room for improvement as described below.

That is, it is desired that the hot water supply system described above can appropriately detect when there is an abnormality in the operating operation, as in the case of other general hot water supply systems. In addition, since it may not be appropriate to continue the operation of the hot water supply system while the abnormality has occurred, it may be necessary to forcibly stop the operation of the hot water supply system when the abnormality occurs.
Here, if the abnormality of the hot water supply system is, for example, an abnormality in which the hot water is not heated, the maintenance person, the user, or the like can detect this relatively easily. On the other hand, in the case of immediate hot water operation, the hot water heated by using the heat exchanger continues to exist in the hot water circulation path unless the hot water tap is opened, and it cannot be touched by the user. No. Therefore, the abnormality of the immediate hot water operation has a peculiarity that cannot be easily detected by the maintenance person or the user.

Japanese Unexamined Patent Publication No. 2020-34193 Japanese Unexamined Patent Publication No. 2011-247487 Japanese Unexamined Patent Publication No. 2003-336899

The present invention has been conceived under the above-mentioned circumstances, and provides a hot water supply system capable of accurately detecting an abnormality in immediate hot water operation. That is the issue.

In order to solve the above problems, the following technical means are taken in the present invention.

The hot water supply system provided by the present invention has a heat exchanger for heating hot water, a hot water outlet connecting the hot water outlet of the heat exchanger and a hot water supply terminal, and one end connected to the vicinity of the hot water supply terminal of the hot water outlet. A return flow path capable of returning the hot water from the hot water outlet to the water inlet of the heat exchanger, a hot water circulation path having a pump for hot water circulation, and a hot water flow rate detection provided in the hot water circulation path. Operation control of immediate hot water operation in which the flow sensor, the temperature sensor for detecting the hot water temperature provided in the return flow path, and the hot water heated by the heat exchanger are circulated or retained in the hot water circulation flow path. A hot water supply system including a control unit capable of performing the above-mentioned operation, wherein the control unit integrates hot water and water detected by using the flow rate sensor after the immediate hot water operation is started. If the detected temperature of the temperature sensor does not rise above the predetermined value even though the flow rate has reached a predetermined value at which the detection temperature of the temperature sensor is normally expected to rise by a predetermined value or more, the hot water supply terminal It is characterized in that it is configured to be able to execute an abnormality determination process for determining whether or not the hot water supply terminal is in the open state and, if the hot water supply terminal is not in the open state, it is determined that there is an abnormality in the immediate hot water operation. It is supposed to be.

With such a configuration, the following effects can be obtained.
That is, when the heated hot water from the heat exchanger is sent out to the hot water circulation path by starting the immediate hot water operation, the integrated flow rate of the heated hot water reaches the predetermined value such as the capacity of the hot water circulation path. If it is sent to the hot water circulation path, the hot water temperature detected by using the temperature sensor should rise above the specified value (however, the hot water supply terminal is opened during the immediate hot water operation and the hot water supply is supplied. Excludes if heated hot water is discharged from the terminal to the outside). According to the present invention, when the immediate hot water operation is started and the above-mentioned normal operation does not occur, the control unit can accurately determine that there is an abnormality in the immediate hot water operation. .. As a result, it is possible to take countermeasures such as forcibly stopping the immediate hot water operation or making the maintenance staff or the user detect that there is an abnormality at an early stage.

In the present invention, preferably, the determination of whether or not the hot water supply terminal is in the open state includes flow rate detection by the flow rate sensor in a state where the pump that was driven at the start of the immediate hot water operation is stopped. It is performed by determining whether or not, and if there is the flow rate detection, it is determined that the hot water supply terminal is in the open state.

According to such a configuration, it is possible to accurately determine whether or not the hot water supply terminal is in the open state by the control of the control unit during the immediate hot water operation.

In the present invention, preferably, when the phenomenon corresponding to the abnormality occurs after the immediate hot water operation is started, the immediate hot water operation is restarted, and the number of repetitions of the phenomenon corresponding to the abnormality is predetermined. When the number of times reaches a plurality of times, the final judgment that there is an abnormality in the immediate hot water operation is made, and the notification operation to that effect is executed.

According to such a configuration, the final judgment that there is an abnormality in the immediate hot water operation is made carefully, and an erroneous judgment can be appropriately prevented.

In the present invention, preferably, the control unit enables the trial run of the immediate hot water operation, and at the time of the trial run, from the time when the hot water is started to be sent from the heat exchanger to the hot water circulation flow path. The integrated flow rate of the heated hot water during the period until the heated hot water reaches the position of the temperature sensor and the temperature detected by the temperature sensor rises is measured, and the measured value is set to the predetermined value. Has been done.

According to such a configuration, the capacity (flow path volume) from the heat exchanger to the temperature sensor in the hot water circulation path can be set to the predetermined value, and this predetermined value can be set to the predetermined value. It can be a value close to the total capacity of. The length of the hot water circulation channel varies depending on the installation conditions of the hot water supply system and is not uniform. On the other hand, according to the above configuration, it is possible to make the control unit learn the approximate value of the capacity of the hot water circulation path by the trial run of the immediate hot water operation, which is convenient.

Other features and advantages of the invention will become more apparent from the following description of embodiments of the invention with reference to the accompanying drawings.

It is a schematic explanatory drawing which shows an example of the hot water supply system which concerns on this invention. It is a schematic explanatory view which shows the operation example of the hot water supply system shown in FIG. 1, (a) shows the example of immediate hot water operation, (b) shows the example of learning control of the capacity of a hot water circulation path. It is a flowchart which shows the operation procedure in the case of performing learning control of the capacity of the hot water circulation path of FIG. 2B. It is a flowchart which shows the operation procedure in the case of performing the hot water operation of FIG. 2A. (A) and (b) are schematic explanatory views showing another example of the hot water supply system which concerns on this invention.

Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings.

The hot water supply system SY shown in FIG. 1 includes a hot water supply device A, a water inlet channel 1, a hot water outlet channel 2, and a return channel 3. The hot water supply device A has a configuration in which a heat exchanger 4 for heating hot water, a burner 5, a control unit 6, and the like are housed in an outer case 7. The burner 5 is, for example, a gas burner or an oil burner. The heat exchanger 4 is configured by using, for example, a fin pipe or the like, and the hot water sent into the heat exchanger 4 can be heated by using the combustion gas generated by the burner 5.

The water inlet 1 is a piping flow path that connects an external water supply source 19 such as a water pipe and a water inlet 4a of the heat exchanger 4 to each other to allow water to enter the heat exchanger 4, and is inside and outside the exterior case 7. It is divided into an internal water inlet 1a and an external water pipe 1b located in each. The external water inlet 1b is also connected to the water supply part side of the mixing tap 8 via the branch pipe part 17. The mixing tap 8 corresponds to an example of a hot water supply terminal.

The hot water outlet 2 is a piping flow path that connects the hot water outlet 4b of the heat exchanger 4 and the hot water supply portion side of the mixing tap 8 to each other to enable hot water supply to the mixing tap 8, and is located inside and outside the outer case 7. It is divided into an internal hot water passage 2a and an external hot water passage 2b. The internal hot water passage 2a is connected to the internal hot water passage 1a via a three-way valve V1 having an adjustable flow rate and a bypass flow path 18, and unheated hot water can be mixed with the hot water flowing through the internal hot water passage 2a. By controlling this mixing ratio, the hot water outlet temperature is controlled to a desired target hot water supply temperature. The internal hot water passage 2a is provided with a temperature sensor Sd for detecting the hot water temperature and a flow rate adjusting valve V2.

The return flow path 3 is configured by connecting a portion near the mixing tap 8 of the hot water passage 2 and an intermediate portion of the internal water inlet passage 1a with the internal return flow path 3a located inside and outside the outer case 7. It is divided into an external return flow path 3b. A pump P for circulating hot water and a flow rate sensor Sb are provided in the internal return flow path 3a.

When the pump P is driven, as shown by the thick line in FIG. 2A, the hot water flowing out from the heat exchanger 4 to the hot water passage 2 can be returned to the heat exchanger 4 via the return flow path 3. Yes, the hot water circulation path C is composed of the heat exchanger 4, the hot water outlet 2, and the return flow path 3. In the immediate hot water operation in the hot water supply system SY, the heated hot water is circulated and circulated through the route shown by the thick line in FIG. 2 (a).
The flow rate sensor Sb is for detecting the flow rate of hot water in the hot water circulation path C. During the immediate hot water operation shown in FIG. 2A, the hot water supply portion side of the mixing tap 8 is opened, and when hot water is discharged, the hot water flow rate detected by the flow rate sensor Sb is reduced.
Note that FIG. 2B will be described later.

Strictly speaking, the portion of the internal water inlet 1a on the heat exchanger 4 side from the connection point with the internal return flow path 3a also corresponds to a part of the return flow path 3 (and the hot water circulation path C). A flow rate sensor Sc and a temperature sensor Sa are provided in the portion. The flow sensor Sc is originally for detecting the flow rate of water entering the heat exchanger 4, and the temperature sensor Sa is for detecting the temperature of water entering the heat exchanger 4.

The control unit 6 is configured by using a microcomputer or the like and executes operation control of each part of the hot water supply device A. As described later, control of immediate hot water operation, learning control for performing immediate hot water operation, And if there is an abnormality in the immediate hot water operation, the abnormality judgment process to detect that fact is also executed.

A remote controller 60 installed in, for example, a bathroom or a kitchen is connected to the control unit 6 by communication. The remote controller 60 includes a plurality of operation switches 60a, a display unit 60b for displaying data, a speaker (not shown) capable of generating various voice messages, warning sounds, and the like.

Next, an example of the operation control in the hot water supply system SY described above and the operation will be described with reference to the flowcharts of FIGS. 3 and 4.

In the hot water supply system SY, it is possible to execute the immediate hot water operation described later, but as a premise, the following "control to learn the capacity of the hot water circulation path C" is executed in advance. This control is executed during the trial run of the hot water supply system SY.

Specifically, when the test run of the immediate hot water operation is selected by first operating the operation switch 60a of the remote controller 60, the pump P is driven by the control of the control unit 6 so that this test run is executed. It is turned on (S1: YES, S2). As a result, the circulation and circulation of hot water in the hot water circulation path C is started, and as a result of the burner 5 starting the drive combustion, the hot water is also started to flow from the heat exchanger 4 to the hot water channel 2 (S3). Along with this, the control unit 6 starts measuring (counting) the integrated flow rate Q of the hot water in the hot water circulation path C by using the flow rate sensor Sb (S4).

On the other hand, the control unit 6 monitors the hot water temperature detected by using the temperature sensor Sa, and when the hot water temperature rises to a predetermined temperature or higher, the counting of the integrated flow rate Q is terminated at that point and the counting is finished. The count value (for example, Qa) is regarded as an approximate value (or an approximate value) of the capacity of the hot water circulation path C and is stored (S5: YES, S6). The situation where the hot water temperature detected by using the temperature sensor Sa rises above a predetermined temperature is as shown in FIG. 2 (b), in which the heated hot water by the heat exchanger 4 is shown by the thick line in the figure. This is the situation where the temperature sensor Sa has reached the location where it is placed. At that time, since the volume of the heated hot water is close to the capacity of the hot water circulation path C, there is no problem even if the above-mentioned count value Qa is regarded as an approximate value Qa of the capacity of the hot water circulation path C. The approximate value Qa corresponds to an example of a predetermined value (normally, a predetermined value at which the detection temperature of the temperature sensor can be expected to rise by a predetermined value or more) in the present invention.
After finishing the above-mentioned processing, both the pump P and the burner 5 are driven off (the drive is turned off).
S7).

Next, a case where the immediate hot water operation is executed will be described.

First, when it is selected to start the hot water operation immediately by operating the remote controller 60 or the like, the pump P and the burner 5 are sequentially driven on by the control of the control unit 6 as in the above-mentioned test run. Then, the heated hot water from the heat exchanger 4 is sent out to the hot water circulation path C (S11: YES, S12, S13). Further, from that point, the control unit 6 starts counting the integrated flow rate Q of the hot water in the hot water circulation path C (S14). Further, in the control unit 6, the abnormality detection counter is set to n = 0 (S15).

After that, when the integrated flow rate Q described above does not exceed the approximate value Qa of the capacity of the hot water circulation path C described above, the hot water temperature detected by the temperature sensor Sa reaches a predetermined temperature (for example, about the same as the target hot water supply temperature). If it rises, the control unit 6 determines that "there is no abnormality in the immediate hot water operation" (S16: YES, S17: YES, S18). When the hot water heated by the heat exchanger 4 reaches the location where the temperature sensor Sa is arranged in the hot water circulation path C, the temperature detected by the temperature sensor Sa rises. Therefore, if such a phenomenon is observed, the hot water is immediately heated. It is considered that there is no abnormality in the operation. If it is determined that there is no abnormality, it is considered unnecessary to notify the fact by using the remote controller 60 or the like, but it can be configured to notify the fact.

When it is determined that there is no abnormality in the immediate hot water operation, the subsequent operation processing procedure is omitted in FIG. 4, but the immediate hot water operation is continuously executed thereafter, and the hot water circulation path C is predetermined. The state in which hot water heated to the temperature circulates and circulates is maintained. In this immediate hot water operation, the mixing tap 8 is opened, an operation to end the immediate hot water operation is performed, or a preset time for ending the immediate hot water operation elapses. finish.
However, in the immediate hot water operation, unlike the above, the heated hot water from the heat exchanger 4 reaches the location where the temperature sensor Sa is arranged, and the detection temperature thereof is the same as in the test run mode shown in FIG. 2 (b). It is also possible to perform an immediate hot water operation in which the driving of the pump P and the burner 5 is stopped when the temperature rises. Even in such an immediate hot water operation, the heated hot water can be retained in the hot water circulation path C, and when the mixing tap 8 is opened, hot water at a desired temperature is immediately discharged. It is possible.

Unlike the above, the integrated flow rate Q may exceed the approximate value Qa of the capacity of the hot water circulation path C without increasing the hot water temperature detected by the temperature sensor Sa (S17: NO, S16: NO). In this case, the control unit 6 drives off the pump P and then determines whether or not the flow rate is detected by the flow rate sensor Sb (S20, S21). In this case, the fact that the flow rate is detected even though the pump P is stopped means that the mixing tap 8 is in the open state and the hot water is discharged. Therefore, when the flow rate is detected, the control unit 6 ends the counting process of the integrated flow rate Q without determining that there is an abnormality (S21: YES, S22). Under this situation, since the mixing tap 8 is opened and the hot water is discharged during the immediate hot water operation, the immediate hot water operation is switched to the normal hot water supply operation.

In step S21 described above, when the mixing tap 8 is not in the open state and the flow rate is not detected, the burner 5 is driven off (S21: NO, S23). Under this situation, there is a high possibility that there is an abnormality in the immediate hot water operation, and it is possible to avoid the danger by turning off the drive of the burner 5. After that, if the numerical value n of the abnormality detection counter is smaller than, for example, "3", the control unit 6 sets the numerical value n of the abnormality detection counter to +1 and resets the count of the integrated flow rate Q, and then pumps P and Each of the burners 5 is driven on, and the immediate hot water operation is substantially restarted (S24: YES, S25 to S27).

In the above-mentioned redoing immediate hot water operation, if the temperature detected by the temperature sensor Sa rises to a predetermined temperature before the integrated flow rate Q exceeds the approximate value Qa, it is determined that there is no abnormality in the immediate hot water operation (S16). : YES, S17: YES, S18).
On the other hand, when the numerical value n of the abnormality detection counter becomes, for example, "3" due to the repetition of the state in which there is a high possibility that there is an abnormality without such a result, the control unit 6 starts the hot water operation immediately. The final judgment that there is an abnormality is made, and the notification operation to that effect is executed (S24: NO, S28). In the present embodiment, on the condition that the situation in which there is a high possibility of abnormality is repeated, it is finally determined that there is an abnormality, so that the reliability of this determination can be made high. ..
The notification operation corresponds to, for example, an image display by the display unit 60b of the remote controller 60, an audio output from a speaker, or the like. When the control unit 6 determines that there is an abnormality in the immediate hot water operation, the counting of the integrated flow rate Q ends (S29), but at this stage, both the pump P and the burner 5 are already driven off. It is said that the immediate hot water operation has already been stopped.

FIG. 5 shows another embodiment of the hot water supply system according to the present invention. In the figure, the same or similar components as those in the above embodiment are designated by the same reference numerals, and duplicate description will be omitted.

The hot water supply system SYa shown in FIG. 5A includes an external bypass flow path 16 that connects the external hot water passage 2b and the external water inlet passage 1b. A part of the external bypass flow path 16 corresponds to a branch pipe portion 17 that enables water to be supplied to the water supply portion side of the mixing tap 8, but the portion closer to the external hot water passage 2b than the branch pipe portion 17 A check valve Va that allows only hot water flow from the external hot water passage 2b side to the external bypass flow path 16 side is provided.
On the other hand, the pump P is provided in the internal water inlet 1a.
The portion shown by the thick line in the figure (b) corresponds to the hot water circulation path C. The return flow path 3 is composed of an external bypass flow path 16, an external water entry channel 1b, and an internal water entry channel 1a.

In the hot water supply system SY of the present embodiment, the external return flow path 3b and the internal return flow path 3a in the previous hot water supply system SY can be eliminated as a component of the hot water circulation path C. Therefore, it is possible to simplify the configuration and reduce the manufacturing cost.

The present invention is not limited to the contents of the above-described embodiments. The specific configuration of each part of the hot water supply system according to the present invention can be variously redesigned within the scope of the present invention.

In the above-described embodiment, the "predetermined value (normally, a predetermined value at which the detection temperature of the temperature sensor can be expected to rise by a predetermined value or more)" in the present invention is regarded as the approximate value Qa of the capacity of the hot water circulation path C. However, it can be a different value. Further, this value is not limited to the value obtained by learning from the control unit 6 at the time of trial operation, and may be a value input by, for example, an installer of the hot water supply system SY by operating the remote controller 60.
The present invention can also be applied to a hot water storage type hot water supply system equipped with a hot water storage tank. In this case, as the heat exchanger for heating hot water, for example, a liquid-liquid / heat exchanger can be used, and high-temperature hot water discharged from the hot water storage tank can be used as a medium for heating hot water.

SY, SY Hot water supply system C Hot water circulation path Sa Temperature sensor Sb, Sc Flow sensor P Pump Va Check valve 1 Inlet 1a Internal inlet 1b External inlet 16 External bypass channel 19 Water supply source 2 Outlet 2a Internal outlet 2b External hot water passage 3 Return flow path 3a Internal return flow path 3b External return flow path 4 Heat exchanger 5 Burner 6 Control unit 7 Exterior case 8 Mixing tap (hot water supply terminal)

Claims (4)

A heat exchanger for heating hot and cold water,
A hot water channel connecting the hot water outlet of the heat exchanger and the hot water supply terminal, one end of which is connected to the vicinity of the hot water supply terminal of the hot water channel, and the hot water of the hot water channel can be returned to the water inlet of the heat exchanger. A hot water circulation path with a return flow path and a pump for hot water circulation,
A flow rate sensor for detecting the flow rate of hot water provided in this hot water circulation path, and
A temperature sensor for detecting the temperature of hot water provided in the return flow path and
A control unit capable of controlling the operation of immediate hot water operation in which hot water heated by the heat exchanger is circulated or retained in the hot water circulation flow path.
It is a hot water supply system equipped with
In the control unit, after the immediate hot water operation is started, the integrated flow rate of hot water detected by using the flow sensor is normally expected to increase the detected temperature of the temperature sensor by a predetermined value or more. When the detection temperature of the temperature sensor does not rise more than a predetermined value even though the value is reached, it is determined whether or not the hot water supply terminal is in the open state, and the hot water supply terminal is not in the open state. The hot water supply system is characterized in that it is configured to be capable of executing an abnormality determination process for determining that there is an abnormality in the immediate hot water operation. The hot water supply system according to claim 1.
The determination of whether or not the hot water supply terminal is in the open state is to determine whether or not the flow rate is detected by the flow rate sensor when the pump that was driven at the start of the immediate hot water operation is stopped. A hot water supply system in which the hot water supply terminal is determined to be in the open state when the flow rate is detected. The hot water supply system according to claim 1 or 2.
When the phenomenon corresponding to the abnormality occurs after the immediate hot water operation is started, the immediate hot water operation is restarted, and when the number of repetitions of the phenomenon corresponding to the abnormality reaches a predetermined plurality of times, A hot water supply system that makes a final judgment that there is an abnormality in the immediate hot water operation and executes a notification operation to that effect. The hot water supply system according to any one of claims 1 to 3.
The control unit enables the trial run of the immediate hot water operation, and at the time of the trial run, the heated hot water is the temperature sensor from the time when the hot water is started to be sent from the heat exchanger to the hot water circulation flow path. A hot water supply system configured to measure the integrated flow rate of the heated hot water in the period from reaching the position of the above to the temperature detected by the temperature sensor and setting the measured value to the predetermined value.

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