JP6214212B2 - Hot water system - Google Patents

Description

  The present invention relates to a hot water supply system for supplying hot water heated and generated by a hot water heater to a hot water mixing tap at a hot water usage destination.

  Conventionally, in a hot water supply system that supplies hot water generated by heating in a water heater to a hot water mixing tap such as a kitchen sink or a wash basin, the hot water heating circulation route is provided, and when the hot water mixing tap is opened, the heating circulation route There has been proposed one having a so-called instant hot water function capable of quickly supplying hot water to a hot and cold water mixing tap (see, for example, Patent Document 1).

  Specifically, referring to FIG. 3, a conventional hot water supply system 7 having an immediate hot water function includes a hot water supply 71 having a heat exchanger 81, a water supply pipe 72 for guiding water from a water supply source to the heat exchanger 81, The hot water heated by the exchanger 81 is provided with a hot water outlet pipe 73 that guides the hot water to the hot water mixing tap P1. In addition, a circulation line 76 for guiding the hot water to the water supply line 73 is bypassed between the water supply line 72 and the hot water supply line 73. When the hot water mixing tap P1 is closed, the heat exchanger 81 is closed. The hot water outlet 812 is connected to the circulation pipe 76 through the hot water outlet pipe 73, and the hot water is circulated in a heating circulation path connected to the water inlet 811 of the heat exchanger 81 via the water supply pipe 72. Furthermore, a water inlet temperature sensor 87 for detecting the water temperature in the water supply pipe 72 is incorporated inside the water heater 71, and the detected temperature of the water inlet temperature sensor 87 is a reference during the heating circulation of the hot water in the heating circulation path. The heating circulation is stopped when the temperature becomes higher. Therefore, when the hot and cold water mixing tap P1 is opened, hot water is promptly supplied to the hot water usage destination through the hot water outlet pipe 73.

JP 7-268916 A

  However, since the conventional hot water supply system is configured to stop the hot water heating circulation based on the water temperature in the water supply pipe, hot water having a temperature higher than the reference is supplied from the heat exchanger to the outlet pipe during the heating circulation. When the water is sent out, movable parts such as a water amount sensor and a bypass servo provided in the water supply pipe are excessively heated, resulting in performance deterioration, and the hot water supply system may not operate normally.

  Further, in the above-described conventional hot water supply system, the circulation line is positioned as close as possible to the downstream side of the outlet line, that is, as close as possible to the hot and cold water mixing tap so that hot water of a desired temperature is quickly supplied from the heating circulation path to the hot water usage destination. It is necessary to extend from the water supply pipe to the water supply pipe. However, with this configuration, it takes time to install the pipe, particularly when the hot water heater is installed at a position relatively away from the hot water usage destination. It was.

  The present invention has been made in view of the above problems, and its purpose is to prevent malfunction of the entire hot water supply system caused by hot water circulation in a hot water supply system having an immediate hot water function, and to improve workability. It is to improve.

The present invention relates to a water heater having a heat exchanger, a water supply conduit for guiding water from the water supply source to the heat exchanger, and a water inlet from the water supply source to a water inlet of a hot water mixer tap provided at a hot water use destination. A water outlet pipe for guiding the hot water heated in the heat exchanger by the heating source to the hot water inlet of the hot water mixing tap, and a hot water inlet of the hot water mixing tap in the hot water outlet pipe A circulation pipe for leading from the upstream side to the water discharge pipe, and the hot water outlet of the heat exchanger are connected to the circulation pipe through the hot water discharge pipe, and further the water inlet of the heat exchanger through the water discharge pipe and the water supply pipe A circulation pump that circulates the hot water in a heating circulation path connected to the outside, an outside air temperature sensor that detects the outside air temperature, and a control unit that controls the operation of supplying hot water to the hot and cold water mixing tap. A check valve that prevents hot water from flowing from the water path to the hot water outlet, and the water temperature in the circulation pipe And a circulation water temperature sensor is provided for detecting, control means, while by heating circulating water by heating circulation path, if the detected temperature of the circulating water temperature sensor becomes higher than a predetermined temperature, thereby interrupting the heating circulation, heating The heating circulation is resumed when a predetermined reference time elapses after the circulation is interrupted, and the reference time is set shorter as the temperature detected by the outside air temperature sensor is lower .

According to the above embodiment, even when hot water having a temperature higher than the reference is sent from the heat exchanger to the outlet pipe during hot water circulation, the heating circulation is interrupted when the hot water reaches the circulation pipe. Therefore, hot water does not flow into the water supply pipeline. Therefore, performance deterioration due to overheating of the movable parts provided in the water supply pipeline is unlikely to occur. In addition, in this case, for example, it is possible to install a pipe that becomes a circulation pipe between the outlet pipe and the outlet pipe arranged in a lower space such as a kitchen sink or a sink. Construction is also easy. In particular, when a predetermined time elapses after the hot water circulation is interrupted, the heating circulation is resumed and the hot water temperature in the heating circulation path is adjusted. Hot water at a desired temperature can be accurately and quickly supplied to a hot water usage destination. In addition, if the outside air temperature is low, the degree of heat release from the heating circulation path increases accordingly, but in this case, the lower the temperature detected by the outside air temperature sensor, the shorter the reference time is set. Regardless of the time, the hot water temperature in the heating circulation path can be kept more constant. Therefore, hot water at a desired temperature can be supplied more accurately and promptly to the hot water usage destination.

  In the hot water supply system, preferably, the circulation pump is provided in a circulation line.

  When the circulation pump is provided in the hot water discharge pipe, hot water always flows through the circulation pump while the hot water supply operation to the hot and cold water mixing tap is being performed, so there is a possibility that the performance of the circulation pump is deteriorated due to overheating. . However, according to the above-described embodiment, hot water does not flow through the circulation pump while the hot water supply operation to the hot / cold water mixing tap is being performed. Therefore, performance degradation due to overheating of the circulation pump hardly occurs. Moreover, in this thing, since it is possible to install a circulation pump collectively with a circulation line in lower spaces, such as a kitchen sink and a wash-stand, for example, construction is still easier.

  As described above, according to the hot water supply system of the present invention, performance deterioration due to overheating of the movable parts of the water supply pipeline is unlikely to occur, and therefore, malfunction of the entire hot water supply system can be prevented. Moreover, since the installation of the piping that becomes the circulation pipe is relatively easy, the workability is also improved.

It is a schematic structure figure of the hot-water supply system concerning an embodiment of the invention. It is an operation | movement flowchart which shows the heating circulation operation | movement of the hot water of the hot water supply system which concerns on embodiment of this invention. It is a schematic block diagram of the conventional hot-water supply system provided with the instant hot water function.

  Next, embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings.

  As shown in FIG. 1, a hot water supply system 1 according to an embodiment of the present invention is an instant hot water that can quickly supply hot water to a hot and cold water mixing tap P1 provided at a hot water use destination such as a kitchen sink or a wash basin. A hot water supply system having a function, wherein the water supplied to the heat exchanger 21 is heated by the combustion exhaust gas of the gas released from the burner 22 to generate hot water, and the heat exchanger 21 from the water supply source. Water supply line 12 for guiding water to the water inlet 211 of the hot water, and a hot water outlet pipe for guiding the hot water heated and generated in the water heater 11 from the hot water outlet 212 of the heat exchanger 21 to the hot water inlet P12 of the hot water mixing tap P1. 13, the outlet pipe 14 for guiding water from the water supply source to the water inlet P11 of the hot water mixer tap P1, and the water fed to the water supply pipe 12 without passing through the heat exchanger 21. And a bypass line 15 for leading to

  Further, between the outlet hot water pipe 13 and the outlet water pipe 14, the hot water fed from the heat exchanger 21 to the hot water outlet pipe 13 is passed through the hot water inlet P12 of the hot water mixer tap P1 without passing through the hot water mixer tap P1. The circulation line 16 for leading from the upstream side to the outlet water line 14 is bypass-connected, and when the hot water mixing tap P1 is closed, the hot water outlet 212 of the heat exchanger 21 is connected to the circulation line 16 through the outlet water line 13. Further, a heating circulation path is formed which is connected to the water inlet 211 of the heat exchanger 21 via the water discharge pipe 14 and the water supply pipe 12.

  In the water heater 11, a gas regulating valve unit 23 that adjusts the amount of gas supplied to the burner 22, a water amount sensor 24 that detects the flow rate of water fed into the water supply pipe 12, and water to the heat exchanger 21. A water amount adjustment valve 25 that can adjust the supply amount of water, and a bypass servo 26 that can adjust the mixing ratio of hot water supplied from the heat exchanger 21 to the hot water discharge line 13 and water supplied from the bypass line 15. And the incoming water temperature sensor 27 which detects the water temperature in the water supply pipe line 12, the external temperature sensor 28 which detects external temperature, and the control circuit 1C which controls operation | movement of the hot water supply system 1 whole are incorporated. The water amount sensor 24, the water amount adjustment valve 25, the bypass servo 26, and the incoming water temperature sensor 27 are arranged in this order from the upstream side in the water supply pipe 12. Further, the bypass servo 26 is provided at a branching portion that branches from the water supply pipe 12 to the bypass pipe 15.

  On the upstream side of the water amount sensor 24 in the water supply pipe 12, an expansion tank 29 is provided to absorb volume expansion accompanying the temperature rise of water in the heating circulation path. The outlet pipe 14 is connected to the downstream side of the portion where the expansion tank 29 is provided in the water supply pipe 12.

  One end of the circulation pipe 16 is connected to the downstream position near the hot water inlet P12 of the hot water mixing tap P1 in the hot water outlet pipe 13, and the other end is connected to the downstream position near the water inlet P11 of the hot water hot water mixing tap P1 in the outlet pipe 14. It is connected and arranged in a lower space such as a kitchen sink or a sink. The circulation line 16 includes a circulation pump 31 that circulates hot water in the heating circulation path, a check valve 32 that prevents hot water from flowing from the outlet pipe 14 to the outlet pipe 13, and the circulation line 16. A circulating water temperature sensor 33 for detecting the water temperature inside is provided.

  The gas regulating valve unit 23, the water quantity sensor 24, the water quantity regulating valve 25, the bypass servo 26, the incoming water temperature sensor 27, the circulation pump 31, and the circulating water temperature sensor 33 are connected to the control circuit 1C through electrical wiring. Although not shown, an operating terminal for instructing the operation of the hot water supply system 1 is connected to the control circuit 1C by electric wiring or wirelessly.

  The control circuit 1C includes a water supply determination unit that determines whether or not the detected water amount of the water amount sensor 24 has reached a predetermined minimum working water amount, a point fire extinguishing execution unit that ignites and extinguishes the burner 22, and a hot water supply line from the water heater 11 Combustion amount adjusting unit that adjusts the heating power of the burner 22 by proportionally controlling the gas regulating valve unit 23 so that the temperature of the hot water sent to 13 reaches a preset hot water temperature Ts, and is sent from the water heater 11 to the hot water supply line 13. The hot water introduced into the tap line 13 from the heat exchanger 21 and the bypass line 15 is adjusted by adjusting the opening degree of the bypass servo 26 in accordance with the detected temperature of the incoming water temperature sensor 27 so that the temperature of the hot water becomes the tapping temperature Ts. A mixing ratio adjusting unit for changing the mixing ratio, a circulation executing unit for operating and stopping the circulation pump 31 according to the detected temperature of the circulating water temperature sensor 33, and a detected water amount of the water amount sensor 24 having the lowest operating water A time measuring unit that measures a combustion stop time when the circulation pump 31 is in a stopped state, and a heating circulation operation executing unit that operates the circulation pump 31 when the combustion stop time reaches a predetermined reference time S, If the detected temperature T1 of the circulating water temperature sensor 33 becomes higher than a predetermined reference temperature Ta during the heating circulation operation, the heating circulation stop operation executing unit for extinguishing the burner 22 and stopping the circulation pump 31, the outside air temperature sensor 28 A circuit configuration such as a time setting unit for setting the reference time S based on the detected temperature Th is provided. The control circuit 1C incorporates a plurality of data tables for a plurality of reference times S that are shorter as the outside air temperature is lower.

  The tapping temperature Ts can be arbitrarily set by the user within a predetermined range (for example, 35 ° C. to 60 ° C.). The reference temperature Ta is set to a value lower than the tapping temperature Ts (for example, tapping temperature Ts−8 ° C.).

  Next, the heating circulation operation of the hot water supply system 1 by the control circuit 1C will be described with reference to FIG. When the operation switch of the operation terminal is turned on, first, the reference time S is selected from the data table incorporated in the control circuit 1C based on the detected temperature (outside temperature) Th of the outside temperature sensor 28 (ST1). ).

  When the detected water amount of the water amount sensor 24 is less than the minimum working water amount and the circulation pump 31 is in a stopped state, monitoring whether the combustion stop time has reached the reference time S is started, and the combustion stop time Reaches the reference time S, the circulation pump 31 is operated. Then, the water circulation in which the water in the heat exchanger 21 is led from the tapping pipe 13 through the circulation pipe 16 to the outlet pipe 14 and then returns to the heat exchanger 21 again through the water supply pipe 12 is started. (ST2 to ST3).

  Although not shown, when the amount of water detected by the water amount sensor 24 reaches the minimum operating water amount due to the start of the water circulation, the burner 22 is ignited and the heating power of the burner 22 and the opening degree of the bypass servo 26 are adjusted based on the tapping temperature Ts. To do. Specifically, when the detected temperature of the incoming water temperature sensor 27 becomes lower than a predetermined temperature, the heating power of the burner 22 is increased and the amount of hot water fed from the bypass pipe 15 to the hot water outlet 13 is reduced. On the other hand, when the detected temperature of the incoming water temperature sensor 27 becomes higher than a predetermined temperature, the heating power of the burner 22 is weakened and the amount of hot water fed from the bypass pipe 15 to the hot water outlet 13 is increased. Thereby, the hot water whose temperature is adjusted to the hot water temperature Ts is led to the circulation pipe 16 through the hot water pipe 13. Accordingly, when the hot and cold water mixing tap P1 is opened in this state, hot water is promptly supplied to the hot water usage destination through the hot water supply pipe 13.

  When the hot and cold water mixing plug P1 is opened, the supply of water from the water supply pipe 12 to the heat exchanger 21 is started. When the detected water amount of the water amount sensor 24 reaches the minimum operating water amount, the heating power of the burner 22 and the opening degree of the bypass servo 26 are adjusted based on the tapping temperature Ts as described above. Thereby, the hot water whose temperature has been adjusted appropriately is supplied to the hot and cold water mixing tap P1 through the hot water supply pipe 13. Then, when the hot and cold water mixing tap P1 is closed and the amount of water detected by the water amount sensor 24 becomes less than the minimum working water amount, the steps after ST1 described above are repeated.

  When the circulation pump 31 is actuated in step ST3, monitoring is started as to whether or not the detected temperature (hereinafter referred to as “circulated hot water temperature”) T1 of the circulating water temperature sensor 33 has become higher than the reference temperature Ta. When the circulating hot water temperature T1 becomes higher than the reference temperature Ta, the circulation pump 31 is stopped, the burner 22 is extinguished, and the hot water circulation in the heating circulation path is interrupted. Thereby, hot water higher than the reference temperature Ta does not flow into the feed water pipe 12 (ST4 to ST5).

  Thus, according to the above-described embodiment, even if hot water having a temperature higher than the reference temperature Ta is sent from the heat exchanger 21 to the tapping pipe line 13 during the hot water circulation in the heating circulation path, the circulation line 16 Since hot water circulation is interrupted when hot water arrives at the hot water, hot water having a temperature higher than the reference temperature Ta does not flow into the water supply pipe 12. Therefore, performance deterioration due to overheating of movable parts such as the water amount sensor 24, the water amount adjustment valve 25, and the bypass servo 26 is unlikely to occur, and malfunction of the entire hot water supply system can be prevented.

  When the temperature of the hot water flowing into the water supply pipe 12 increases, the heating power of the heat exchanger 21 is reduced by that amount to reduce the heating power of the burner 22, but the heating power of the burner 22 is temporarily reduced during the hot water circulation. When the hot water mixing tap P1 is opened in this state (water circulation state), the water introduced from the water supply pipe 12 to the heat exchanger 21 cannot be sufficiently heated and supplied to the hot water usage destination. The temperature of the hot water may drop temporarily. However, in this case, hot water having a temperature higher than the reference temperature Ta does not flow into the water supply pipe 12 during hot water circulation, so that the heating power of the burner 22 is maintained in a state larger than a predetermined value (for example, “medium fire”). Therefore, even if the hot and cold water mixing plug P1 is opened in this state, more heat is applied to the water introduced from the water supply pipe 12 to the heat exchanger 21 than in the high temperature circulation state. Therefore, the degree of the temporary hot water temperature drop described above can be reduced.

  In addition, if a predetermined reference time S has elapsed since the heating circulation operation was interrupted, the heating circulation operation is resumed and the hot water temperature in the heating circulation path is adjusted, so that when the hot water mixing tap P1 is opened, Hot water at a desired temperature can be accurately and quickly supplied to a hot water usage destination. In addition, when the outside air temperature is low, the degree of heat radiation from the heating circulation path increases accordingly. However, in this case, the reference time S is set shorter as the outside air temperature is lower, so that it depends on the installation environment and the operation time. Therefore, the hot water temperature in the heating circulation path can be kept more constant. Therefore, hot water having a desired temperature can be more accurately and promptly supplied to the hot water usage destination.

  Furthermore, according to the above-described embodiment, since the circulation pipe 16 is installed in a lower space such as a kitchen sink or a wash basin, the construction is also easy. Further, since the circulation pump 31, the check valve 32, and the circulation water temperature sensor 33 can be unitized together with the circulation pipe 16, and can be installed collectively in a lower space such as a kitchen sink or a wash basin, the construction is further performed. Easy.

  Moreover, according to the said embodiment, while the hot-water mixing tap P1 is opened and the hot-water supply operation | movement which supplies the hot water produced | generated by the hot water heater 11 from the hot-water supply pipe line 13 to the hot-water mixing tap P1 is performed, it circulates. Since hot water does not circulate in the pump 31, performance deterioration due to overheating of the circulation pump 31 hardly occurs. Therefore, it is possible to more reliably prevent malfunction of the entire hot water supply system.

  The circulation pump 31 may be provided in the water discharge pipe 14 or the water supply pipe 12. Further, the check valve 32 and the circulating water temperature sensor 33 may be provided upstream of the circulation pump 31 in the circulation path 16 (on the side of the hot water supply pipe 13).

DESCRIPTION OF SYMBOLS 1 Hot-water supply system 11 Hot-water supply machine 12 Water supply line 13 Outlet line 14 Outlet line 16 Circulation line 21 Heat exchanger 211 Water inlet 212 of a heat exchanger 22 Hot water outlet 22 of a heat exchanger Burner (heating source)
31 Circulating pump 32 Check valve 33 Circulating water temperature sensor 1C Control circuit P1 Hot water mixing tap P11 Hot water mixing tap water inlet P12 Hot water mixing tap hot water inlet

Claims (2)

A water heater having a heat exchanger, a water supply conduit for guiding water from the water supply source to the heat exchanger, and a water inlet for guiding the water from the water supply source to the water inlet of the hot water mixing tap provided at the hot water usage destination From the upstream side of the hot water inlet of the hot water mixing tap in the hot water mixing tap, the hot water heated in the heat exchanger by the heating source, and the hot water heating pipe for guiding the hot water to the hot water inlet of the hot water mixing tap Heating circulation in which the circulation pipe for leading to the water discharge pipe and the hot water outlet of the heat exchanger are connected to the circulation pipe through the hot water supply pipe, and further to the water inlet of the heat exchanger through the water discharge pipe and the water supply pipe A circulation pump that circulates the hot water in the path, an outside air temperature sensor that detects the outside air temperature, and a control unit that controls the operation of supplying hot water to the hot water mixing tap ,
The circulation pipe is provided with a check valve for preventing hot water from flowing from the outlet pipe to the outlet pipe, and a circulating water temperature sensor for detecting the water temperature in the circulation pipe,
The control means interrupts the heating circulation when the temperature detected by the circulating water temperature sensor is higher than a predetermined temperature while heating and circulating hot water in the heating circulation path , and a predetermined reference time after the heating circulation is interrupted. When the time elapses, the heating circulation is resumed, and the reference time is set shorter as the temperature detected by the outside air temperature sensor is lower . The hot water supply system according to claim 1,
A hot water supply system in which the circulation pump is provided in a circulation line.

Images