JP2019015419A - Hot water supply device - Google Patents

Abstract

To provide a hot water supply device which suppress generation of erosion so as not to degrade usability by a user.SOLUTION: The present invention includes a water supply pipe 6, a heat exchanger 5, a hot water supply pipe 7, a heating means 2 for heating the water flowing in the heat exchanger 5, a bypass pipe 8, a mixing valve 9 for mixing the hot water from the heat exchanger 5 and the water from the bypass pipe 8, a flow rate detecting means 11 for detecting a flow rate of the water flowing in the heat exchanger 5, and a flow rate adjusting means 14 for controlling the flow rate of the flown-out hot water. A hot water flow-out operation is performed in which the hot water at a predefined temperature from the heat exchanger 5 and the water from the bypass pipe 8 are flown out as hot water at a temperature based on the flown-out hot water temperature. During the hot water flow-out operation, when it is judged that the detection flow rate of the flow rate detecting means 11 reaches an erosion risk flow rate, a setting state of an eco mode is judged. When the eco mode is not set, a heat-exchanger outlet target temperature is changed to an erosion-preventive temperature that is higher than the predefined temperature. When the eco mode is set, an opening degree of the flow rate adjusting means 14 is controlled to further closing direction.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a hot water supply apparatus that suppresses the occurrence of erosion and does not impair user convenience as much as possible.

  Conventionally, in this type, a water supply pipe, a heat exchanger provided downstream of the water supply pipe, a hot water supply pipe provided downstream of the heat exchanger and terminated with a hot water tap, and the heat exchanger are circulated. A burner that heats water, a bypass pipe that connects a water supply pipe and a hot water supply pipe to bypass the heat exchanger, a bypass water amount adjustment valve in the bypass pipe, and a hot water adjustment valve that controls the flow rate of hot water provided in the hot water pipe The hot water heated by the heat exchanger and the water from the bypass pipe are mixed so as to reach the preset hot water temperature set by the remote controller, and the hot water set temperature is set by the remote controller. Accordingly, the hot water supply amount adjustment valve is controlled so as to have a specific flow rate for suppressing the occurrence of corrosion (crushed) in the hot water supply flow path due to the flow rate of the fluid. (For example, refer to Patent Document 1.)

JP 2000-274819 A

  By the way, in the conventional one, the specific flow rate is changed according to the hot water set temperature set by the remote controller, and the flow rate discharged from the hot water tap is limited. Therefore, the user cannot obtain the desired hot water flow rate. In some cases, the user's convenience is impaired.

  In order to solve the above problems, the present invention provides a water supply pipe, a heat exchanger provided downstream of the water supply pipe, a hot water supply pipe provided downstream of the heat exchanger, and the heat exchanger. Heating means for heating the water flowing through, a bypass pipe connecting the water supply pipe and the hot water supply pipe to bypass the heat exchanger, and a connection portion between the hot water supply pipe and the bypass pipe provided for the heat exchange A mixing valve that mixes the hot water flowing out from the vessel and the water from the bypass pipe, and the water supply pipe that is provided downstream of the connecting portion between the water supply pipe and the bypass pipe and flows into the heat exchanger Flow rate detecting means for detecting the flow rate of water, flow rate adjusting means for controlling the hot water flow rate, hot water temperature setting means for setting the temperature of hot water discharged from the mixing valve, and control means for controlling the operation thereof And the control means causes the heat exchanger to flow out. The heat exchange outlet target temperature of hot water is set to a predetermined specified temperature, the heating means is controlled so that the hot water flowing out from the heat exchanger becomes the specified temperature, and the specified value from the heat exchanger is set. In a hot water supply apparatus for performing a hot water discharge operation for controlling the mixing valve to discharge hot water having a temperature and water from the bypass pipe so as to become hot water having a temperature based on a hot water setting temperature set by the hot water temperature setting means, The eco mode setting means for setting the eco mode so as to perform the energy saving operation by restricting the energy by the selection operation of the normal operation is provided, and the control flow rate detected by the flow rate detection means during the hot water operation is When it is determined that the erosion risk flow rate at which erosion may occur has been reached, it is determined whether the eco mode is set by the eco mode setting means, When the co-mode is not set, the control means changes the heat exchange outlet target temperature to an anti-corrosion temperature higher than the specified temperature, while when the eco-mode is set, the flow rate The opening degree of the adjusting means is controlled to be closed more than before.

  According to a second aspect of the present invention, when the detected flow rate detected by the flow rate detection unit reaches the erosion danger flow rate at which erosion may occur, and the eco mode is not set, the control is performed. The means sets the erosion prevention temperature higher as the detected flow rate detected by the flow rate detecting means is larger.

  According to a third aspect of the present invention, when the heat exchange outlet target temperature is changed to the anti-corrosion temperature during the hot water operation, the control means performs the heat exchange until the time of the hot water operation is stopped. The outlet target temperature was maintained at the erosion prevention temperature.

  According to a fourth aspect of the present invention, the control means sets the heat exchanger outlet target temperature to the specified value when the hot water outlet has been stopped when the heat exchanger outlet target temperature is changed to the erosion prevention temperature during the hot water operation. It was supposed to return to temperature.

  According to the first aspect of the present invention, when the control means determines that the detected flow rate detected by the flow rate detection means has reached the dangerous erosion flow rate that may cause erosion during the hot water operation, the eco mode is set. It is determined whether the eco mode has been set by the means, and if the eco mode has not been set, the control means changes the heat exchange outlet target temperature to an anti-corrosion temperature higher than the specified temperature, while the eco mode has been set. If it has been set, the opening degree of the flow rate adjusting means is controlled so as to be closed more than before, so that there is no risk of erosion during normal hot water operation without the eco mode set. At the flow rate, the heat exchange outlet target temperature is kept low, the amount of heat consumed by the heating means is reduced to improve thermal efficiency, and the heat exchange outlet target temperature is set above the specified temperature only when there is a risk of erosion. Also Since the flow rate of the water or hot water flowing through the hot water side flow path is reduced, the occurrence of erosion can be suppressed, and the hot water flow rate does not change only by changing the heat exchange outlet target temperature. Therefore, the convenience of the user is not impaired. In addition, during the hot water operation when the eco mode is set, the flow rate adjustment means does not change the opening of the flow rate adjustment means at the flow rate without risk of erosion, so the hot water flow rate is more than necessary. It is not restricted and does not impair the user's convenience, and controls the opening of the flow rate adjustment means so that it closes more than the previous opening only when there is a risk of erosion. As a result, the hot water flow rate is limited and the flow rate of the water or hot water flowing through the hot water channel is reduced, so that the occurrence of erosion can be suppressed, and the heat exchange outlet can be changed only by changing the opening of the flow rate adjusting means. Since the target temperature does not change, the hot water can be discharged with good thermal efficiency. In addition, the hot water flow rate is limited only when the flow rate at which there is a risk of causing erosion is detected, but the user sets the eco mode to consciously perform energy-saving operation. The restriction of the flow rate is recognized as an energy saving function of water saving, and the loss of convenience is tolerated to some extent.

  Further, according to claim 2, when the detected flow rate detected by the flow rate detection unit reaches an erosion risk flow rate at which erosion may occur, and when the eco mode is not set, the control unit The higher the detected flow rate detected by the flow rate detection means, the higher the anti-corrosion temperature is set, so that an appropriate anti-corrosion temperature corresponding to the flow rate can be set, and the occurrence of erosion is suppressed, It is possible to suppress the deterioration of the thermal efficiency accompanying the heat exchange outlet target temperature rise as much as possible.

  According to the third aspect, when the heat exchange outlet target temperature is changed to the erosion prevention temperature during the hot water operation, the control means sets the heat exchange outlet target temperature until the hot water operation is stopped. By maintaining the anti-corrosion temperature, the heat exchange outlet target temperature is not changed many times during the hot water operation, so the hot water can be discharged comfortably with little temperature fluctuation without disturbing the temperature control performance. It is something that can be done.

  According to the fourth aspect of the present invention, the control means returns the heat exchange outlet target temperature to the specified temperature when the hot water outlet at which the heat exchange outlet target temperature has been changed to the anti-corrosion temperature stops during the hot water operation. As a result, at the start of the next hot-water operation, hot water with high thermal efficiency can be performed in a flow rate region where there is no risk of erosion.

The schematic block diagram of the hot-water supply apparatus of one Embodiment of this invention. The flowchart which shows the hot water operation in the hot water supply apparatus of the same embodiment. Explanatory drawing explaining the state before and behind implementation of the anti-corrosion control which changes the heat exchanger outlet target temperature in the hot water supply apparatus of the same embodiment. Explanatory drawing explaining the state before and behind implementation of the anti-corrosion control which controls a water proportional valve in the hot water supply apparatus of the same embodiment.

  Next, a hot water supply apparatus according to an embodiment of the present invention will be described with reference to FIG.

  DESCRIPTION OF SYMBOLS 1 is the hot water supply apparatus of this embodiment, 2 is a burner as a heating means which burns fuel using kerosene etc. as a fuel, 3 is a hot-water tap provided in predetermined places, such as a kitchen and a washroom, 4 is hot water supply It is a remote control as an operation means for remotely operating the device 1.

  5 is a fin-and-tube heat exchanger, 6 is provided upstream of the heat exchanger 5 and feeds water supplied from a water supply source to the heat exchanger 5, and 7 is provided downstream of the heat exchanger 5. The hot water supply pipe 8 for supplying hot water to the hot water tap 3 provided at the end through which the hot water heated by the heat exchanger 5 is circulated is branched from the water supply pipe 6, and the water supply pipe 6 and the hot water supply pipe 7 are connected. A bypass pipe for bypassing the heat exchanger 5, 9 is a mixing valve that is provided at a connection portion between the hot water supply pipe 7 and the bypass pipe 8 and mixes hot water heated by the heat exchanger 5 and water from the bypass pipe 8. The mixing valve 9 discharges hot water having a desired temperature, in which the mixing ratio of hot water and water is adjusted, by adjusting the valve opening of the internal valve body. The water supply pipe 6, the hot water supply pipe 7, and the bypass pipe 8 constitute a hot water supply passage through which hot water supply water flows.

  A water supply temperature sensor 10 is provided in the water supply pipe 6 to detect the temperature of the water supply, and 11 is a water provided in the water supply pipe 6 on the downstream side of the connection portion between the water supply pipe 6 and the bypass pipe 8 and flows into the heat exchanger 5. A flow rate sensor as a flow rate detecting means for detecting the flow rate of the hot water, and 12 is a heat exchange outlet temperature as a heat exchange outlet temperature detecting means provided in the hot water supply pipe 7 upstream of the connecting portion between the hot water supply pipe 7 and the bypass pipe 8. The heat exchange outlet temperature sensor 12 is a sensor that detects the temperature of hot water flowing out of the heat exchanger 5. Reference numeral 13 denotes a tapping temperature sensor as a tapping temperature detecting means for detecting the temperature of the hot water mixed by the mixing valve 9, and reference numeral 14 denotes a downstream side of a connection portion (mixing valve 9 connection position) between the hot water supply pipe 7 and the bypass pipe 8. It is a water proportional valve as a flow rate adjusting means provided in the hot water supply pipe 7 for controlling the flow rate of hot water discharged.

  15 is a bathtub, 16 is a hot water pipe that branches from the hot water supply pipe 7 downstream of the mixing valve 9 and supplies hot water to the bathtub 15. The hot water pipe 16 includes a hot water valve 17 that opens and closes the hot water pipe 16. A bath flow rate sensor 18 that detects a hot water flow rate per hour to the bathtub 15 and a double check valve 19 that prevents a reverse flow of bathtub water from the bathtub 15 are provided.

  The remote controller 4 includes a hot water supply temperature setting switch 20 serving as a hot water temperature setting means for setting a hot water temperature to be discharged from the mixing valve 9 and supplied to the hot water tap 3, and hot water is discharged from the mixing valve 9 through a hot water filling pipe 16. Bath temperature setting switch 21 as a hot water temperature setting means for setting the hot water temperature to be supplied to 15, and the start of a hot water filling operation in which the hot water at the bath set temperature is poured into the bathtub 15 to fill the hot water. Hot water filling switch 22 for instructing, eco mode switch 23 as an eco mode setting means for setting an eco mode so as to perform energy saving operation by restricting energy more than normal time, the state of hot water supply device 1 and hot water temperature setting switch 20 The hot water supply set temperature as the hot water set temperature set in, the bath set temperature as the hot water set temperature set by the bath temperature setting switch 21, the set hot water amount, In which the display unit 24 Komodo displays the like whether it is set is provided. When the eco mode switch 23 is turned ON by the user's selection operation and the eco mode is set, the hot water supply temperature displayed on the display unit 24 of the remote controller 4 is not changed, and the hot water discharged from the hot water tap 3 is not changed. The temperature of the hot water poured into the bathtub 15 is set without changing the temperature to a predetermined temperature (for example, 1 ° C.) lower than the set temperature of the hot water supply or changing the bath set temperature displayed on the display unit 24 of the remote controller 4. A predetermined amount (for example, 1 ° C.) lower than the temperature, or the set hot water amount displayed on the display unit 24 of the remote controller 4 is not changed. (For example, 10L) Lower the set temperature to lower the fuel amount than usual, or reduce the amount of hot water (water usage) and heat the reduced amount of water. Required fuel Min in which normally you can perform a energy-saving operation for reducing than during.

  Reference numeral 25 is a control unit that mainly controls the microcomputer and receives signals from the sensors of the hot water supply device 1 and signals from the remote controller 4 to control the driving of the actuators. The control unit 25 flows out of the heat exchanger 5. When having the function of setting the heat exchange outlet target temperature of hot water and discharging hot water at the set temperature set by the hot water supply temperature setting switch 20 or the bath temperature setting switch 21, the control means 25 controls the heat exchange outlet temperature. The combustion amount of the burner 2 is controlled so that the temperature of the hot water detected by the sensor 12 becomes the set heat exchange outlet target temperature, that is, the amount of heating given to the water flowing through the heat exchanger 5 by the burner 2 is controlled. The hot water temperature detected by the hot water temperature sensor 13 is the hot water based on the set temperature set by the hot water supply temperature setting switch 20 or the bath temperature setting switch 21. And it controls the opening degree of the joint 9. The hot water of the temperature based on the set temperature set by the hot water supply temperature setting switch 20 or the bath temperature setting switch 21 is set to the eco mode other than the hot water of the hot water supply set temperature or the hot water of the bath set temperature. Hot water having a temperature lower than the preset hot water supply temperature or hot water having a temperature lower than the set temperature of the bath.

  In addition, the control means 25 has a predetermined possibility that the flow rate sensor 11 may cause erosion in the pipes constituting the hot water supply flow path during the hot water discharge operation of performing hot water from the hot water tap 3 or filling the bathtub 15. When the flow rate is detected, the erosion prevention control is executed. In the erosion prevention control, the eco mode switch 23 is turned on when the flow rate sensor 11 detects the predetermined flow rate or more during the hot water operation. In the normal time when the eco mode is not set, the control means 25 changes the heat exchange outlet target temperature to a target temperature higher than the target temperature set so far, while the flow rate sensor during the hot water discharge operation. When the eco mode switch 23 is turned on by the user's selection operation and the eco mode is set when the 11 detects the predetermined flow rate or more, the control means 25 Controlled in the closing direction the opening of Reiben 14 restricts the hot water flow rate. Details of the anti-erosion control will be described later.

  Next, the hot water operation of the hot water supply apparatus 1 according to this embodiment will be described with reference to the flowchart of FIG. Here, only the hot water operation for discharging hot water from the hot water tap 3 will be described, and the hot water operation for filling the bathtub 15 is only the difference between the hot water tap 3 and the bathtub 15. Therefore, since it is the same as the hot water discharge operation for discharging hot water from the hot water tap 3, the description is omitted.

  Now, when the hot water tap 3 at an appropriate location is opened and the hot water discharge is started, the flow rate sensor 11 detects the flow of this water, and the control means 25 is based on the flow rate detected by the flow rate sensor 11. It is determined whether or not the detected flow rate detected by 11 is equal to or higher than the minimum operating flow rate (step S1). Water is heated. At this time, the heat exchange outlet target temperature of the hot water flowing out from the heat exchanger 5 is a predetermined specified temperature (for example, 40 ° C.) higher than the hot water supply set temperature (for example, 40 ° C.) set by the hot water supply temperature setting switch 20 of the remote controller 4. For example, the control means 25 controls the combustion amount of the burner 2 so that the hot water temperature detected by the heat exchange outlet temperature sensor 12 becomes the specified temperature.

  And the hot water of the specified temperature which flowed out from the heat exchanger 5 and the water from the bypass pipe 8 are mixed by the mixing valve 9, and the control means 25 detects that the hot water temperature detected by the hot water temperature sensor 13 is the hot water supply temperature setting switch 20. When the hot water temperature detected by the hot water temperature sensor 13 is higher than the hot water supply set temperature, the hot water side is squeezed to The valve opening of the valve body inside the mixing valve 9 is adjusted so as to open the side, and hot water at a hot water supply set temperature is supplied to the hot-water tap 3 and discharged, and the hot water temperature detected by the hot water temperature sensor 13 is When the temperature is lower than the hot water supply set temperature, the water side is throttled and the valve opening of the mixing valve 9 is adjusted to open the hot water side so that hot water at the hot water set temperature is supplied to the hot water tap 3 and discharged. It is. Note that the control by the control means 25 described above is a preset erosion risk flow rate in which the flow rate detected by the flow rate sensor 11 is greater than or equal to the minimum operating flow rate and may cause erosion in the pipes constituting the hot water supply flow path. Is a control that is performed during a normal hot water operation in which the eco mode is not set, and the flow rate detected by the flow sensor 11 is a range that is greater than or equal to the minimum operating flow rate and less than the erosion risk flow rate. The hot water temperature detected by the hot water temperature sensor 13 is indicated in the hot water temperature setting switch 20 in the hot water temperature detection switch 13 when only the difference is shown in the hot water operation when the eco mode is set. The opening degree of the mixing valve 9 is controlled so that the temperature is lower than the set temperature by a predetermined temperature (for example, 1 ° C.), and the energy saving operation is performed as compared with the normal time.

  In addition, during the hot water operation, the control means 25 determines whether or not the detected flow rate detected by the flow sensor 11 is equal to or higher than the erosion risk flow rate based on the flow rate detected by the flow sensor 11 (step S2). When it is determined that the dangerous flow rate is exceeded, the control means 25 determines whether or not the eco mode is set, that is, whether or not the eco mode switch 23 is turned on (step S3), and the eco mode is set. If it judges that it is not, the control means 25 will change the heat exchanger outlet target temperature from the specified temperature (50 degreeC) which was the heat exchanger outlet target temperature until then to the erosion prevention temperature (for example, temperature higher than a specified temperature). The heat exchange outlet target temperature is changed to 57 ° C. (step S4). On the other hand, when the control unit 25 determines in step S3 that the eco mode is set, that is, the eco mode switch 23 is turned on by the user's selection operation, the water proportional valve 14 is opened to the previous degree. It controls to the direction which closes more, and restrict | limits the tapping flow rate (step S5). In step S2, the control unit 25 determines whether or not the detected flow rate detected by the flow sensor 11 is equal to or higher than the erosion danger flow rate. However, the control unit 25 detects the detected flow rate detected by the flow sensor 11. It may be determined whether or not a state where the erosion risk flow rate has been exceeded is continuously detected for a predetermined time (for example, 10 seconds).

  Here, the state of the hot water supply apparatus 1 when the anti-corrosion control for shifting from the process of step S3 to the process of step S4 is performed will be described in detail with reference to FIG. As a premise, among the pipes constituting the hot water supply flow path, for example, the inner diameter of the pipe constituting the heat exchanger 5 is the smallest, the inner diameter of the pipe is φ14, the feed water temperature is 15 ° C., the heat exchange outlet target temperature is 50 ° C. It is assumed that the detected flow rate detected by the flow sensor 11 exceeds the erosion danger flow rate when the hot water discharge operation is performed at a set temperature of 40 ° C. The numerical values given here are merely examples and are not particularly limited.

  First, as shown in FIG. 3, the detected flow rate detected by the flow rate sensor 11 as a flow rate flowing into the heat exchanger 5 at a total flow rate of 22 L / min during a normal hot water supply operation in which the eco mode is not set. Is 15.7 L / min, the flow rate in the pipe of the heat exchanger 5 is 1.70 m / s converted from the flow rate of 15.7 L / min, and the control means 25 detects that the detected flow rate is the erosion risk flow rate. Therefore, the target temperature of the heat exchange outlet is increased from 50 ° C., which was the target temperature up to that time, to 57 ° C., which is the anti-corrosion temperature. Here is a supplementary explanation of erosion. Corrosion is a corrosion phenomenon that occurs in pipes through which fluid flows, and corrodes so that the inner surface of the pipes are removed in a horseshoe shape when the flow velocity of the fluid is high. If the flow rate exceeds 1.5 m / s, the risk of erosion is increased. In the hot water supply apparatus 1 shown in FIG. 3, when the flow rate exceeds 13.8 L / min (about 1.5 m / s in terms of flow velocity), it is crushed in the pipe of the heat exchanger 5 having a pipe having an inner diameter φ14. Since there is a risk of erosion, 13.8 L / min is stored in advance as the erosion risk flow rate, and the control means 25 compares the flow rate detected by the flow sensor 11 with the erosion risk flow rate. Judgment is made as to whether or not erosion may occur. Note that the erosion risk flow rate has a close relationship with the pipe inner diameter (or channel cross-sectional area) of the pipe constituting the hot water supply channel, and the pipe inner diameter (or channel cross-sectional area) of the pipe constituting the hot water channel. Is determined in consideration of

  As described above, when the heat exchange outlet target temperature is changed from 50 ° C. to 57 ° C., the hot water temperature mixed by the mixing valve 9 is increased, and hot water having a hot water supply set temperature of 40 ° C. is discharged. However, the mixing valve 9 is controlled so that the hot water side is squeezed and the water side is opened, and the flow rate of water flowing through the heat exchanger 5 is reduced to 13.1 L / min (1.42 m / s in terms of flow velocity). In addition, the flow rate of water flowing through the bypass pipe 8 is increased to 8.9 L / min. At this time, the opening degree of the water proportional valve 14 is not changed before and after the execution of the anti-corrosion control, and the hot water flow rate remains 22 L / min, and the hot water flow rate is not limited, which impairs the convenience for the user. There is no.

  As described above, the heat exchange outlet target temperature is higher than the specified temperature when the detected flow rate detected by the flow rate sensor 11 reaches the erosion danger flow rate during normal hot water supply operation in which the eco mode is not set. By changing to the anti-corrosion temperature, the heat exchange outlet target temperature is kept low at a flow rate at which there is no risk of erosion, reducing the amount of heat consumed by the burner 2 and improving the thermal efficiency. By setting the heat exchange outlet target temperature to be higher than the specified temperature only at a flow rate at which there is a risk of occurrence of food, the water supply pipe downstream of the connection between the water supply pipe 6 and the bypass pipe 8 in the hot water supply flow path. 6 and the heat exchanger 5 and the hot water supply pipe 7 and the bypass pipe 8 and the flow rate of the water or hot water flowing through the hot water side flow path consisting of the hot water supply pipe 7 on the upstream side is reduced, thereby suppressing the occurrence of erosion. Is a heat exchange outlet Since no tapping flow rate only by changing the target temperature changes, those never impairing the user's convenience.

  In addition, when the heat exchange outlet target temperature is changed to the erosion prevention temperature, the control means 25 maintains the heat exchange outlet target temperature at the erosion prevention temperature until the time of the hot water discharge operation is stopped. In this case, since the heat exchange outlet target temperature is not changed many times during the hot water operation, it is possible to perform a comfortable hot water with little temperature fluctuation without disturbing the temperature control performance. .

  Further, when the hot water outlet at the time when the heat exchange outlet target temperature is changed to the erosion prevention temperature is stopped, the control means 25 may return the heat exchange outlet target temperature to the original temperature which is the original temperature. In this case, at the start of the next hot-water operation, hot water with high thermal efficiency can be performed in a flow rate region where there is no risk of erosion.

  In the present embodiment, the erosion prevention temperature is fixed at 57 ° C., however, the erosion prevention temperature may be set according to the detected flow rate detected by the flow sensor 11, for example, When the detected flow rate is within the range of 13.8 L / min to less than 16 L / min, the erosion prevention temperature is 57 ° C., and when the detected flow rate is within the range of 16 L / min to less than 18 L / min, the erosion prevention temperature is set. The controller 25 can set an appropriate anti-corrosion temperature corresponding to the flow rate by setting the anti-corrosion temperature higher as the detected flow rate detected by the flow sensor 11 is larger, such as 60 ° C. Thus, it is possible to suppress the deterioration of the thermal efficiency accompanying the increase in the target temperature of the heat exchange outlet as much as possible while suppressing the occurrence of erosion.

  Next, the state of the hot water supply device 1 when the anti-corrosion control for shifting from the process of step S3 to the process of step S5 is performed will be described in detail with reference to FIG. As a premise, among the pipes constituting the hot water supply flow path, for example, the inner diameter of the pipe constituting the heat exchanger 5 is the smallest, the inner diameter of the pipe is φ14, the feed water temperature is 15 ° C., the heat exchange outlet target temperature is 50 ° C. It is assumed that the detected flow rate detected by the flow sensor 11 exceeds the erosion danger flow rate when the hot water discharge operation is performed at a set temperature of 40 ° C. The numerical values given here are merely examples and are not particularly limited. Here, since the eco mode is set, the hot water supply set temperature displayed on the display unit 24 of the remote controller 4 is 40 ° C., but the hot water set temperature is controlled at 39 ° C. for control.

  First, the detected flow rate detected by the flow sensor 11 is 15 as the flow rate flowing into the heat exchanger 5 at a total flow rate of 22 L / min during the hot water operation in the eco mode in which the eco mode is set by the user's selection operation. In the case of .1 L / min, the flow rate in the pipe of the heat exchanger 5 is 1.64 m / s converted from the flow rate 15.1 L / min, and the control means 25 detects that the detected flow rate exceeds the erosion risk flow rate. The opening of the water proportional valve 14 is controlled so as to close from the previous opening until the detected flow detected by the flow sensor 11 falls below the erosion danger flow (excluding full closing) ), Restricting the flow rate of hot water.

  And as mentioned above, when the opening degree of the water proportional valve 14 is controlled in the closing direction, the hot water flow rate (total flow rate) is limited from 22 L / min to 19 L / min, and the water flowing through the heat exchanger 5 is controlled. The flow rate is reduced to 13.0 L / min (1.41 m / s in terms of flow velocity). At this time, the heat exchange outlet target temperature is not changed before and after the execution of the erosion prevention control, and remains at 50 ° C., which is better in thermal efficiency than when the heat exchange outlet target temperature is increased.

  As described above, when the detected flow rate detected by the flow sensor 11 reaches the erosion danger flow rate during the hot water operation when the eco mode is set, the opening degree of the water proportional valve 14 is closed in a direction closer to the opening degree so far. By controlling, since the opening degree of the water proportional valve 14 is not changed in the flow rate range where there is no risk of erosion, the outlet water flow rate is not restricted more than necessary. By controlling the opening of the water proportional valve 14 in a direction that closes more than the previous opening only at a flow rate that does not impair the convenience of the user and there is a risk of causing erosion, Since the flow rate is limited and the flow rate of water or hot water flowing through the hot water side flow path is reduced, the occurrence of erosion can be suppressed, and the heat exchange outlet target temperature can be obtained only by changing the opening of the water proportional valve 14. Because it does not change, the hot water in the state of good heat efficiency It is a function. In addition, the hot water flow rate is limited only when the flow rate at which there is a risk of causing erosion is detected, but the user sets the eco mode to consciously perform energy-saving operation. The restriction of the flow rate is recognized as an energy saving function of water saving, and the loss of convenience is tolerated to some extent.

  In addition, during the hot water operation when the eco mode is set, after the opening degree of the water proportional valve 14 is controlled to be closed more than the previous opening degree, the detected flow rate of the flow sensor 11 is crushed during the hot water operation. The control means 25 calculates that the flow rate is less than the erosion danger flow rate even if the opening degree of the water proportional valve 14 is reduced to the original opening degree before being controlled in the closing direction. The control means 25 may return the opening degree of the water proportional valve 14 to the original opening degree in this case, and in this case, it is necessary even during the hot water operation when the eco mode is set. When there is no, there is no restriction on the flow rate of the hot water, so that the convenience for the user is not impaired.

  Furthermore, during the hot water supply operation when the eco mode is set, when the hot water is stopped in a time when the opening of the water proportional valve 14 is controlled to be closed in a direction to be closed from the previous opening, the control means 25 It may be possible to return to the original opening before controlling the opening in the closing direction. In this case, at the start of the next hot-water operation, the discharge flow rate is limited in a flow rate region where there is no risk of erosion. Therefore, the convenience of the user is not impaired.

  The present invention is not limited to the above-described embodiment. In the present embodiment, the present invention is applied to the hot water supply apparatus 1 that can discharge hot water from the hot water tap 3 and fill the bathtub 15 with water. The present invention may be applied to a single-function hot water supply device 1 that can perform only hot water supply, or may be applied to a hot water supply device 1 having a bath water replenishment function.

  In this embodiment, the combustion burner 2 is used as the heating means for heating the water flowing through the heat exchanger 5, but the heating means for heating the water flowing through the heat exchanger 5 is a heat pump heating means. There is no particular limitation.

  In the present embodiment, when the eco mode is set, the hot water supply set temperature displayed on the display unit 24 of the remote controller 4 is not changed, and the hot water temperature discharged from the hot water tap 3 is set higher than the hot water supply set temperature. The bath temperature set on the remote controller 4 is not changed, the bath set temperature displayed on the display unit 24 of the remote controller 4 is not changed, and the temperature of the hot water poured into the bathtub 15 is set lower than the bath set temperature, Although the set hot water amount displayed on the display unit 24 is not changed, a control example that can perform an energy saving operation of reducing the predetermined hot water amount poured into the bathtub 15 by a predetermined amount is given. However, the present invention is not limited to the above, and any device can be used as long as it can perform an energy-saving operation that reduces the amount of fuel and water used than usual.

DESCRIPTION OF SYMBOLS 1 Hot water supply apparatus 2 Burner 5 Heat exchanger 6 Water supply pipe 7 Hot water supply pipe 8 Bypass pipe 9 Mixing valve 11 Flow rate sensor 14 Water proportional valve 20 Hot water supply temperature setting switch 21 Bath temperature setting switch 23 Eco mode switch 25 Control means

Claims (4)

  A water supply pipe, a heat exchanger provided downstream of the water supply pipe, a hot water supply pipe provided downstream of the heat exchanger, heating means for heating water flowing through the heat exchanger, the water supply pipe, and the A bypass pipe that connects the hot water pipe and bypasses the heat exchanger, and hot water that flows out of the heat exchanger provided in a connection portion between the hot water pipe and the bypass pipe and water from the bypass pipe are mixed. A mixing valve, a flow rate detection means for detecting a flow rate of water flowing into the heat exchanger provided in the water supply pipe downstream of a connection portion between the water supply pipe and the bypass pipe, and a hot water flow rate is controlled. A flow rate adjusting means; a hot water temperature setting means for setting the temperature of hot water to be discharged from the mixing valve; and a control means for controlling the operation of the hot water, and the control means heats the hot water flowing out from the heat exchanger. Set the target exit temperature to a predetermined temperature And controlling the heating means so that the hot water flowing out from the heat exchanger reaches the specified temperature, and the hot water at the specified temperature from the heat exchanger and the water from the bypass pipe are In a hot water supply device that performs a hot water discharge operation in which hot water is discharged by controlling the mixing valve so that the hot water has a temperature based on the set hot water temperature set by the setting means, the energy is limited by the user's selection operation, and energy saving operation is performed. The eco-mode setting means for setting the eco-mode is set so that the detected flow rate detected by the flow rate detection means reaches a risk of erosion risk that erosion may occur during the hot water operation. Is determined by the eco mode setting means, and if the eco mode is not set, the control means When the heat exchange outlet target temperature is changed to an anti-corrosion temperature higher than the specified temperature, and the eco mode is set, the opening degree of the flow rate adjusting means is more closed than before. A hot water supply apparatus characterized by being controlled.   When the detected flow rate detected by the flow rate detection unit reaches the erosion risk flow rate at which erosion may occur, and the eco mode is not set, the control unit is configured to output the flow rate detection unit. The hot water supply apparatus according to claim 1, wherein the erosion prevention temperature is set higher as the detected flow rate detected in step 1 increases.   When the heat exchanger outlet target temperature is changed to the erosion prevention temperature during the hot water operation, the control means sets the heat exchanger outlet target temperature to the erosion until the hot water operation is stopped. The hot water supply apparatus according to claim 1, wherein the hot water supply apparatus is maintained at a prevention temperature.   The control means is configured to return the heat exchanger outlet target temperature to the specified temperature when the hot water outlet is stopped when the heat exchanger outlet target temperature is changed to the erosion prevention temperature during the hot water operation. The hot-water supply apparatus as described in any one of Claim 1 to 3 characterized by these.

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