JP2015001309A - Hot water heating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hot water heating device that includes a structure capable of securely sensing closing failure of a low-temperature bypass on-off valve during simultaneous operation of a high-temperature heating terminal and a low-temperature heating terminal, etc.SOLUTION: In a hot water heating device 1, during simultaneous operation of a high-temperature heating terminal 3 and a low-temperature heating terminal 4, a low-temperature bypass on-off valve 18 is opened and a heating temperature by using a heating heat exchanger 2 is controlled to a temperature suitable for the high-temperature heating terminal 3, and for a low-temperature supply passage 12, high-temperature heating water introduced from a high-temperature branch passage 11 and heating water introduced from a low-temperature bypass passage 15 are mixed with each other so as to perform control to a temperature suitable for the low-temperature heating terminal 4. The hot water heating device 1 includes control means that determines whether or not the low-temperature bypass on-off valve 18 is opened after predetermined time has passed since opening control of the low-temperature bypass on-off valve 18 and that changes the heating temperature by using the heating heat exchanger 2 to a temperature lower than that suitable for the high-temperature heating terminal 3 when determining that the low-temperature bypass on-off valve 18 is not opened, during the simultaneous operation.

Description

  The present invention relates to a hot water heating apparatus, and more particularly to an apparatus capable of detecting a closing failure of a low temperature bypass on / off valve that is opened and closed when heating water is supplied to a low temperature heating terminal.

  2. Description of the Related Art Conventionally, hot water heating apparatuses that perform hot water heating by circulatingly supplying heating water heated by a heating heat exchanger to a heating terminal have been put to practical use. In this type of hot water heating apparatus, a high temperature heating terminal (bathroom heating, fan convector, etc.) that heats by circulatingly supplying heating water of about 80 ° C., a low temperature that heats by circulatingly supplying heating water of about 60 ° C. There are two temperature circuits that are equipped with a heating terminal (floor heating, panel radiator, etc.), and are capable of operating both heating terminals simultaneously without being limited to single operation of the high temperature heating terminal or the low temperature heating terminal.

  The hot water heater provided with the above two temperature circuits is disclosed by various literatures. For example, in the hot water heating apparatus shown in FIG. 2 of Patent Document 1, a heating heat exchanger that heats heating water with a burner, and a first circulation path for circulatingly supplying high-temperature heating water to a high-temperature heating terminal (first load) And a second circulation path for circulatingly supplying low-temperature heating water to the low-temperature heating terminal (second load), and the first and second heat medium supply valves (open / close valves) are provided in the first and second circulation paths. The structure of the installed two temperature circuit is disclosed.

  In the hot water heating apparatus of Patent Document 1, the heating water temperature supplied to the high temperature heating terminal or the low temperature heating terminal while opening and closing the first heat medium supply valve or the second heat medium supply valve at the time of trial operation (water filling). And a technique for detecting an open / closed state and a failure state of the first heat medium supply valve or the second heat medium supply valve by comparing the heating water temperature after heat radiation at the heating terminal.

  By the way, at the time of simultaneous operation of the high temperature heating terminal and the low temperature heating terminal, the low temperature heating water supplied to the low temperature heating terminal includes the high temperature heating water heated by the heating heat exchanger and the return heating radiated by the high temperature heating terminal. Produced by mixing with water. A low temperature bypass opening / closing valve is generally installed in the low temperature bypass passage through which the return heating water flows, and the high temperature heating water and the return heating water are mixed by opening the low temperature bypass opening / closing valve during simultaneous operation. The adjusted low-temperature heating water is supplied to the low-temperature heating terminal.

JP-A-6-288559

  However, if the above-mentioned low-temperature bypass on / off valve is closed due to sticking or disconnection, the high-temperature heating water and the return heating water cannot be mixed, and the temperature-controlled low-temperature heating water is normally supplied to the low-temperature heating terminal. There is a risk that it cannot be supplied. For this reason, during simultaneous operation of the high-temperature heating terminal and the low-temperature heating terminal, the high-temperature heating water heated by the heating heat exchanger flows directly into the low-temperature heating terminal, causing discomfort to the user and causing burns. There is a risk of stagnation.

  Therefore, it is necessary to detect the failure of the low temperature bypass on / off valve by using the technology of Patent Document 1, but when the failure is detected by the technology of Patent Document 1, only the failure of the low temperature bypass on / off valve is notified. Then, since high temperature heating water continues to be supplied to the low temperature heating terminal, the hot water heating operation must be stopped. However, if the operation of the low-temperature heating terminal (especially floor heating in the winter season) is stopped, it will be uncomfortable for the user, so it is desirable to continue the hot water heating operation even if the low-temperature bypass on / off valve fails. .

  It is an object of the present invention to provide a hot water heating apparatus having a structure capable of reliably detecting a closed failure of a low temperature bypass on / off valve during simultaneous operation of a high temperature heating terminal and a low temperature heating terminal. However, it is to provide a device capable of continuing the hot water heating operation, a device having a structure capable of improving safety, and the like.

  The hot water heating apparatus according to claim 1 is a hot water heating apparatus for performing hot water heating by circulatingly supplying heating water heated by a heating heat exchanger to a heating terminal, and for supplying high temperature heating water to the high temperature heating terminal. A low-temperature supply passage having a high-temperature supply passage, a low-temperature supply passage for supplying low-temperature heating water to the low-temperature heating terminal, and a heating return passage for returning the heating water from the heating terminal to the heating heat exchanger. The passage is connected to a high temperature branch passage branched from the high temperature supply passage and a low temperature bypass passage branched from a downstream side of a circulation pump installed in the heating return passage and provided with an on-off valve. During simultaneous operation of the terminal and the low-temperature heating terminal, the on-off valve is opened and the heating temperature in the heating heat exchanger is controlled to a temperature suitable for the high-temperature heating terminal. Introduced from branch passage In the hot water heating apparatus that mixes the heated hot water and the heating water introduced from the low temperature bypass passage to adjust the temperature to be suitable for the low temperature heating terminal, the open / close valve is controlled to be opened during the simultaneous operation. Then, after a predetermined time has passed, it is determined whether or not the on-off valve has been opened, and if it is determined that the on-off valve has not been opened, the heating temperature in the heating heat exchanger is set to the high temperature heating terminal. It is characterized by comprising control means for changing to a temperature lower than the temperature suitable for the above.

  According to a second aspect of the present invention, there is provided the hot water heating apparatus according to the first aspect, wherein an expansion tank is installed on the upstream side of the circulation pump in the heating return passage, and the control means controls the opening of the on-off valve to elapse a predetermined time. Then, when the temperature of the heating water flowing through the low temperature supply passage is the same as the temperature of the heating water flowing through the high temperature supply passage, and the temperature of the heating water flowing through the high temperature supply passage and the expansion tank When the temperature difference with the temperature of the inside heating water is equal to or higher than a set temperature, it is determined that the on-off valve is not opened.

  According to the first aspect of the present invention, during simultaneous operation of the high temperature heating terminal and the low temperature heating terminal, after opening and closing the opening / closing valve and a predetermined time has elapsed, it is determined whether or not the opening / closing valve has been opened. If it is determined that the heating temperature is not open, the control means for changing the heating temperature in the heating heat exchanger to a temperature lower than the temperature suitable for the high temperature heating terminal is provided. It is possible to determine whether or not the on-off valve is closed during simultaneous operation with the heating terminal.

  Even in the event of a shut-off failure of the on-off valve, it is possible to continue the hot water heating operation by lowering the heating temperature of the heating water by the heating heat exchanger and continuing the simultaneous operation. Without impairing the performance, it is possible to prevent high-temperature heating water from flowing into the low-temperature heating terminal and improve safety.

  According to the invention of claim 2, when the temperature of the heating water flowing through the low-temperature supply passage is the same as the temperature of the heating water flowing through the high-temperature supply passage, the control means is the heating water in the expansion tank. When the temperature difference between the temperature of the heating water flowing through the high-temperature supply passage is equal to or higher than the set temperature, it is determined that the on-off valve is not open. It is possible to make a failure determination, and to prevent erroneous detection when the heating load is small and the temperature of the heating water returning from the heating load is hardly reduced.

It is the schematic which shows the structure of the hot water heating apparatus which concerns on an Example. It is a flowchart which concerns on control at the time of simultaneous operation with a high temperature heating terminal and a low temperature heating terminal at the time of high temperature heating terminal independent operation. It is a flowchart which concerns on the control at the time of low temperature heating terminal independent operation.

  Hereinafter, embodiments of the present invention will be described based on examples.

First, the overall configuration of the hot water heater 1 will be described.
As shown in FIG. 1, the hot water heating apparatus 1 includes a heating heat exchanger 2, a high temperature heating terminal 3, a low temperature heating terminal 4 (corresponding to a heating terminal), a hot water heating circuit 5, a control unit 6, and the like. Heating water heated by the exchanger 2 is circulated and supplied to the high temperature heating terminal 3 and the low temperature heating terminal 4 through the hot water heating circuit 5 to perform hot water heating.

Next, the heating heat exchanger 2 will be described.
The heating heat exchanger 2 is a heat exchanger that heats the heating water flowing through the hot water heating circuit 5 using, for example, high-temperature hot water stored in the hot water tank 7, and constitutes a heating source of the hot water heating device 1. doing. The heating heat exchanger 2 includes a heat exchange passage portion 5a that is a part of the hot water heating circuit 5, and a heat exchange passage portion 8a that is a part of the circulation circuit 8 that circulates the hot water in the hot water storage tank 7. Heat is exchanged between the hot water flowing from the hot water and the heating water flowing through the hot water heating circuit 5.

  In addition, as mentioned above, in the heating heat exchanger 2, the hot water of the hot water heating apparatus 1 is heated using the high temperature hot water stored in the hot water tank 7, but it is particularly necessary to limit to this structure. The heating water may be heated by combustion heat using a heat exchanger of a known gas water heater, and various known ones can be used as long as the heating water flowing through the hot water heating circuit 5 can be heated. Can be adopted.

Next, the high temperature heating terminal 3 and the low temperature heating terminal 4 will be described.
As shown in FIG. 1, the high temperature heating terminal 3 circulates and supplies heating water of about 80 ° C., and is composed of, for example, a bathroom dryer or a fan convector. Heating is performed by circulatingly supplying heating water at about 60 ° C., and for example, it is composed of floor heating, a panel radiator, or the like, but it is not necessary to limit to these.

Next, the hot water heating circuit 5 will be described.
As shown in FIG. 1, the hot water heating circuit 5 includes a high temperature supply passage 11 for supplying high temperature heating water to the high temperature heating terminal 3 and a low temperature supply passage 12 for supplying low temperature heating water to the low temperature heating terminal 4. A heating return passage 13 for returning heating water radiated from the high temperature heating terminal 3 and the low temperature heating terminal 4 to the heating heat exchanger 2, a high temperature branch passage 14 connected to the low temperature supply passage 12, a low temperature bypass passage 15, and the like. ing.

  The upstream end of the high temperature supply passage 11 is connected to the outlet of the heating heat exchanger 2, and the downstream end of the high temperature supply passage 11 is connected to the inlet of the high temperature heating terminal 3. A temperature sensor 21 for high-temperature heating water for detecting the temperature of the heating water (Ta) flowing through the high-temperature supply passage 11 is installed in the vicinity of the outlet of the heating heat exchanger 2 in the high-temperature supply passage 11. A high temperature heating terminal side opening / closing valve 3 a is installed in the vicinity of the inlet of the high temperature heating terminal 3.

  The upstream end of the heating return passage 13 is connected to the outlet of the high temperature heating terminal 3 and the outlet of the low temperature heating terminal 4, and the downstream end of the heating return passage 13 is connected to the inlet of the heating heat exchanger 2. The heating return passage 13 is provided with an expansion tank 16 capable of allowing the volume expansion of heating water by heating from the upstream side to the downstream side, and a circulation pump 17 for circulating the heating water to the hot water heating circuit 5. Has been.

  A low temperature bypass passage 15 is branched from the downstream side of the circulation pump 17 in the heating return passage 13. A bypass passage 20 branched from the high temperature supply passage 11 is connected to the heating return passage 13 upstream of the expansion tank 16. The expansion tank 16 is provided with an expansion tank heating water temperature sensor 22 for detecting the heating water temperature (Tb) in the expansion tank 16.

  The upstream end of the low temperature supply passage 12 is connected to a junction between the downstream end of the high temperature branch passage 14 branched from the high temperature supply passage 11 and the downstream end of the low temperature bypass passage 15 branched from the heating return passage 13. The downstream end of 12 is connected to the inlet of the low temperature heating terminal 4. A temperature sensor 23 for low-temperature heating water for detecting the temperature (Tc) of the heating water flowing through the low-temperature supply passage 12 is installed upstream of the low-temperature supply passage 12. In the vicinity, a low temperature heating terminal side opening / closing valve 4a is provided.

  The high temperature branch passage 14 is provided with a check valve 19 that allows only the flow from the high temperature supply passage 11 to the low temperature supply passage 12. A low temperature bypass opening / closing valve 18 (corresponding to an opening / closing valve) is installed in the low temperature bypass passage 15. The high temperature heating terminal side opening / closing valve 3a, the low temperature heating terminal side opening / closing valve 4a, and the low temperature bypass opening / closing valve 18 heat the thermal element with a heater and open the valve by expansion of the thermal element, and the elastic force of the spring member. Although each of the two-position control thermal valves is configured to be closed, it is not necessary to limit to the thermal valves.

Next, the control unit 6 will be described.
As shown in FIG. 1, the hot water heater 1 is controlled by a control unit 6. The control unit 6 is capable of data communication with the operation remote controller 25 that can be operated by the user. The switch operation of the operation remote controller 25 and the detection signals of the various temperature sensors 21 to 23 are transmitted to the control unit 6. The unit 6 controls the heating operation for heating the heating water in the heating heat exchanger 2, the operation / stop of the circulation pump 17, and the switching of the open / close states of the various on-off valves 3 a, 4 a, 18. The operation (single operation of the high temperature heating terminal 3, single operation of the low temperature heating terminal 4, simultaneous operation of the high temperature heating terminal 3 and the low temperature heating terminal 4, etc.) is performed.

Next, the independent operation of the high temperature heating terminal 3 will be described.
At the time of independent operation of the high temperature heating terminal 3, the control unit 6 sets the heating temperature by the heating heat exchanger 2 to a temperature suitable for the high temperature heating terminal 3 (for example, 80 ° C.), and opens the high temperature heating terminal side opening / closing valve 3a. Then, the low temperature heating terminal side opening / closing valve 4a is closed, and the low temperature bypass opening / closing valve 18 is closed.

  The low-temperature heating water taken out from the expansion tank 16 by driving the circulation pump 17 flows into the heating heat exchanger 2 through the heating return passage 13, and the high-temperature heating water heated by the heating heat exchanger 2. Is supplied to the high temperature heating terminal 3 through the high temperature supply passage 11. The return heating water radiated from the high temperature heating terminal 3 is returned to the expansion tank 16 through the heating return passage 13.

Next, the independent operation of the low-temperature heating terminal 4 will be described.
During the independent operation of the low temperature heating terminal 4, the control unit 6 sets the heating temperature by the heating heat exchanger 2 to a temperature suitable for the low temperature heating terminal 4 (for example, 60 ° C.), and closes the high temperature heating terminal side opening / closing valve 3a. Then, the low temperature heating terminal side opening / closing valve 4a is opened, and when the load on the low temperature heating terminal 4 is small, the low temperature bypass opening / closing valve 18 is set to be closed.

  The low-temperature heating water taken out from the expansion tank 16 by driving the circulation pump 17 flows into the heating heat exchanger 2 through the heating return passage 13, and the heating water heated by the heating heat exchanger 2 is The high temperature supply passage 11 flows into the low temperature supply passage 12 through the high temperature branch passage 14 and is supplied to the low temperature heating terminal 4 through the low temperature supply passage 12. The return heating water radiated by the low temperature heating terminal 4 is returned to the expansion tank 16 through the heating return passage 13.

  In addition, when the load of the low temperature heating terminal 4 is large, in order to increase the flow rate of the heating water to the low temperature heating terminal 4, the heating temperature by the heating heat exchanger 2 is higher than the temperature suitable for the low temperature heating terminal 4. (For example, 65 ° C.), and the low temperature bypass opening / closing valve 18 is set to be opened.

  The low-temperature heating water taken out from the expansion tank 16 by the drive of the circulation pump 17 flows into the heating return passage 13 and the low-temperature bypass passage 15 and flows into the heating heat exchanger 2 through the heating return passage 13. The heated water is heated, and the high-temperature heating water passes from the high-temperature supply passage 11 through the high-temperature branch passage 14 and is mixed with the heating water introduced from the low-temperature bypass passage 15 to a temperature suitable for the low-temperature heating terminal 4 (for example, 60 ° C. The temperature-adjusted heating water is supplied to the low-temperature heating terminal 4 through the low-temperature supply passage 12. The return heating water radiated by the low temperature heating terminal 4 is returned to the expansion tank 16 through the heating return passage 13.

Next, simultaneous operation of the high temperature heating terminal 3 and the low temperature heating terminal 4 will be described.
At the time of simultaneous operation of the high temperature heating terminal 3 and the low temperature heating terminal 4, the control unit 6 sets the heating temperature by the heating heat exchanger 2 to a temperature suitable for the high temperature heating terminal 3 (for example, 80 ° C.). The side open / close valve 3a and the low temperature heating terminal side open / close valve 4a are opened, and the low temperature bypass open / close valve 18 is opened.

  The low-temperature heating water taken out from the expansion tank 16 by the drive of the circulation pump 17 flows into the heating return passage 13 and the low-temperature bypass passage 15 and flows into the heating heat exchanger 2 through the heating return passage 13. The heated heating water is heated, the high temperature heating water is supplied from the high temperature supply passage 11 to the high temperature heating terminal 3, and the heating water introduced from the high temperature branch passage 14 is heated from the low temperature bypass passage 15. And the temperature-adjusted heating water is supplied to the low-temperature heating terminal 4 through the low-temperature supply passage 12. The return heating water radiated by the high temperature heating terminal 3 and the low temperature heating terminal 4 is returned to the expansion tank 16 through the heating return passage 13.

  Next, the failure determination control of the low temperature bypass opening / closing valve 18 and the check valve 19 executed simultaneously during the hot water heating operation, and the heating temperature in the heating heat exchanger 2 when the low temperature bypass opening / closing valve 18 is in the closed failure are set to the high temperature heating terminal. The control for changing to a temperature lower than the temperature suitable for 3 will be described based on the flowcharts of FIGS. In the figure, the symbol Si (i = 1, 2,...) Indicates each step. A control program relating to this control is stored in the control unit 6 in advance.

  In the flowchart of FIG. 2, when this control is started, it is first determined in S1 whether or not the hot water heating operation start condition is satisfied based on the operation of the operation remote controller 25 or the like. If the condition for starting the hot water heating operation is satisfied, that is, if the determination of S1 is Yes, the process proceeds to S2, and if the determination of S1 is No, S1 is repeated.

  Next, in S2, it is determined whether the hot water heating operation is a single operation of the low temperature heating terminal 4. When the hot water heating operation is the single operation of the low temperature heating terminal 4, that is, when the determination of S2 is Yes, the process proceeds to S12 (see the flowchart of FIG. 3), and the hot water heating operation is other than the single operation of the low temperature heating terminal 4 If, in other words, if the determination in S2 is No, the process proceeds to S3.

  Next, in S3, it is determined whether the hot water heating operation is a simultaneous operation of the high temperature heating terminal 3 and the low temperature heating terminal 4. When the hot water heating operation is simultaneous operation of the high temperature heating terminal 3 and the low temperature heating terminal 4, that is, when the determination of S3 is Yes, the process proceeds to S4, and when the hot water heating operation is a single operation of the high temperature heating terminal 3, That is, if the determination in S3 is No, the process proceeds to S5.

  Next, in S4, the hot water heating operation is set to the simultaneous operation mode of the high temperature heating terminal 3 and the low temperature heating terminal 4. In this simultaneous operation mode, the heating temperature by the heating heat exchanger 2 is set to a temperature suitable for the high temperature heating terminal 3 (for example, 80 ° C.) by the control unit 6, and the high temperature heating terminal side opening / closing valve 3a and the low temperature heating terminal side are set. The on-off valve 4a is opened, the low-temperature bypass on-off valve 18 is set to be opened, the circulation pump 17 is driven, the simultaneous operation of the high temperature heating terminal 3 and the low temperature heating terminal 4 is executed, and the process proceeds to S6. .

  In S5, when the hot water heating operation is set to the single operation mode of the high temperature heating terminal 3, the control unit 6 changes the heating temperature by the heating heat exchanger 2 to a temperature suitable for the high temperature heating terminal 3 (for example, 80 ° C.). The high temperature heating terminal side opening / closing valve 3a is opened, the low temperature heating terminal side opening / closing valve 4a is closed, the low temperature bypass opening / closing valve 18 is closed, the circulation pump 17 is driven, and the high temperature heating terminal is opened. 3 is executed, and this series of controls is terminated. In this single operation mode, since the heating water does not flow through the low temperature bypass passage 15 and the high temperature branch passage 14, the failure determination of the low temperature bypass on / off valve 18 and the check valve 19 is not performed.

  Next, in S6, it is determined whether or not a predetermined time (for example, about 1 to 3 minutes) has elapsed since the circulation pump 17 is driven. If the predetermined time has elapsed, that is, if the determination in S6 is Yes. , The process proceeds to S7, and if the determination of S6 is No, S6 is repeated.

  Next, in S7, the detection signals of the various temperature sensors 21 to 23 are read. That is, the detection signals of the temperature sensor 21 for the high temperature heating water, the temperature sensor 22 for the heating water in the expansion tank, and the temperature sensor 23 for the low temperature heating water are read, and the heating water temperatures Ta, Tb, and Tc are calculated based on these detection signals. Calculate each one.

  Next, in S8, whether or not the heating water temperature Tc flowing through the low temperature supply passage 12 is approximately the same as the heating water temperature Ta flowing through the high temperature supply passage 11, and the heating water temperature Ta flowing through the high temperature supply passage 11 is determined. And the temperature difference between the heating water temperature Tb in the expansion tank 16 and the set temperature α (for example, 10 ° C.) or more is determined.

  The above-mentioned comparable temperature is within a set value (for example, 1 to 3 ° C.) where the temperature difference is small, and the heating water temperature Tc flowing through the low temperature supply passage 12 and the heating water temperature Ta flowing through the high temperature supply passage 11 are The temperatures are substantially equal. In the case of a closed failure in which the low temperature bypass opening / closing valve 18 is not opened, the heating water does not flow back to the low temperature bypass passage 15, and high temperature heating water passes from the high temperature supply passage 11 through the high temperature branch passage 14 to the low temperature supply passage 12. And is supplied directly to the low temperature heating terminal 4 without being mixed with the return heating water from the low temperature bypass passage 15.

  By the way, in the determination of whether or not the temperature difference between the heating water temperature Ta in the high temperature supply passage 11 and the heating water temperature Tb in the expansion tank 16 is equal to or higher than the set temperature α, if the heating load is small, heat is not radiated by the heating load. The hot heating water returns to the expansion tank 16 and the temperature of the heating water temperature Tb in the expansion tank 16 increases. In this state, even if the low temperature bypass opening / closing valve 18 is opened, the temperature of the heating water temperature Tc flowing through the low temperature supply passage 12 does not decrease, but becomes the same temperature as the heating water temperature Ta, and the low temperature bypass opening / closing valve 18 is closed. Misdetection of failure. Therefore, the determination of whether or not the temperature is equal to or higher than the set temperature α is made to prevent erroneous detection. In addition, when it determines with it being false detection by S8, it is necessary to set the heating temperature by the heating heat exchanger 2 low.

  That is, in S8, when the heating water temperature Tc flowing through the low temperature supply passage 12 is approximately the same as the heating water temperature Ta flowing through the high temperature supply passage 11, the heating water temperature Ta flowing through the high temperature supply passage 11 and the expansion tank When the temperature difference with the heating water temperature Tb in 16 is equal to or higher than the set temperature α, it is determined that the low temperature bypass on / off valve 18 is closed, the determination in S8 is Yes, the process proceeds to S9, and the determination in S8 is performed. In No, it transfers to S10.

  Next, in S9, the heating temperature of the heating heat exchanger 2 is lowered, and the failure notification of the low temperature bypass on / off valve 18 is executed. That is, after the low temperature bypass on / off valve 18 is controlled to open, it is determined whether or not the low temperature bypass on / off valve 18 has been opened. If it is determined that there is a closed failure, the heating temperature in the heating heat exchanger 2 is set to the high temperature heating terminal. 3 is changed to a temperature lower than the temperature suitable for 3 (for example, 60 ° C.), the low temperature bypass opening / closing valve 18 is informed of a failure state by a display warning or a voice warning, etc. This series of control ends.

  The temperature sensor 21 for the high-temperature heating water, the temperature sensor 22 for the heating water in the expansion tank, the temperature sensor 23 for the low-temperature heating water, the control unit 6, and the control programs S6 to S9 correspond to the control means of the present invention. is there.

  Next, in S10 after it is determined in S8 that the low temperature bypass on / off valve 18 is operating normally, the heating water temperature Tc flowing through the low temperature supply passage 12 is approximately the same as the heating water temperature Tb in the expansion tank 16. It is determined whether or not the temperature.

  In this S8, when the check valve 19 of the high temperature branch passage 14 is closed, high temperature heating water does not flow through the high temperature branch passage 14, so the low temperature supply passage 12 is connected via the low temperature bypass passage 15. The return heating water in the expansion tank 16 flows as it is. That is, when the heating water temperature Tc flowing through the low temperature supply passage 12 is approximately the same as the heating water temperature Tb in the expansion tank 16, that is, when the check valve 19 is out of order, the determination in S10 is Yes. If the determination at S10 is No, this series of control is terminated while the simultaneous operation is being executed.

  Next, in S11, when it is determined that the check valve 19 is closed, the user is informed of the check valve 19 being in a failed state by a display warning or a voice warning, and the simultaneous operation is performed. This series of control is terminated.

  In S12 of the flowchart of FIG. 3, it is determined whether or not the heating load for the low-temperature heating terminal 4 is greater than or equal to the set value. If the heating load is greater than or equal to the installation value, that is, if the determination in S12 is Yes, the process proceeds to S13. If the determination in S12 is No, the process proceeds to S17. As the set value of the heating load, for example, when the low-temperature heating terminal 4 is a floor heating system including three systems, the heating amount necessary for heating two or more systems of floor heating may be used as a reference value. It is not necessary to limit to this.

  Next, in S13, the hot water heating operation is set to the single operation mode of the low temperature heating terminal 4 using the low temperature bypass on / off valve 18. In this single operation mode, the control unit 6 sets the heating temperature of the heating heat exchanger 2 to a temperature higher than the temperature suitable for the low temperature heating terminal 4, closes the high temperature heating terminal side on-off valve 3a, The terminal side opening / closing valve 4a is opened, the low temperature bypass opening / closing valve 18 is set to be opened, the circulation pump 17 is driven, the single operation of the low temperature heating terminal 4 is executed, and the process proceeds to S14.

  Next, in S14, it is determined whether or not a predetermined time (for example, about 1 to 3 minutes) has elapsed since the circulation pump 17 is driven. If the predetermined time has elapsed, that is, if the determination in S14 is Yes, It transfers to S15 and repeats S14 while the determination of S14 is No.

  Next, in S15, the detection signals of the various temperature sensors 22 and 23 are read. That is, the detection signals of the temperature sensor 22 for the heating water in the expansion tank and the temperature sensor 23 for the low temperature heating water are read, respectively, and the heating water temperatures Tb and Tc are calculated based on these detection signals.

  Next, in S <b> 16, it is determined whether or not the heating water temperature Tc flowing through the low temperature supply passage 12 is approximately the same as the heating water temperature Tb in the expansion tank 16. When the check valve 19 of the high temperature branch passage 14 is closed, a high temperature heating water does not flow through the high temperature branch passage 14, so that the low temperature supply passage 12 is connected to the expansion tank 16 via the low temperature bypass passage 15. The heating water will flow as it is. That is, when the heating water temperature Tc flowing through the low temperature supply passage 12 is approximately the same as the heating water temperature Tb in the expansion tank 16, that is, when the check valve 19 is out of order, the determination in S16 is Yes. The process proceeds to S17, and if the determination in S16 is No, this series of control is terminated.

  Next, when it is determined in S17 that the check valve 19 is in a closed failure, the user is notified by a display warning, a voice warning or the like that the check valve 19 is in a failed state, and the low temperature heating terminal 4 is This series of controls is terminated while the operation is being executed.

  Next, in S18, the hot water heating operation is set to the single operation mode of the low temperature heating terminal 4 that does not use the low temperature bypass on / off valve 18. In this single operation mode, the control unit 6 sets the heating temperature by the heating heat exchanger 2 to a temperature suitable for the low temperature heating terminal 4, closes the high temperature heating terminal side opening / closing valve 3a, and closes the low temperature heating terminal side opening / closing valve. 4a is opened, the low temperature bypass on / off valve 18 is set to be closed, the circulation pump 17 is driven, the single operation of the low temperature heating terminal 4 is executed, and the process proceeds to S19.

  Next, in S19, it is determined whether or not a predetermined time (for example, about 1 to 3 minutes) has elapsed since the driving of the circulation pump 17, and if the predetermined time has elapsed, that is, if the determination in S19 is Yes, The process proceeds to S20, and if the determination in S19 is No, S19 is repeated.

  Next, in S20, the detection signals of the various temperature sensors 21 to 23 are read. That is, the detection signals of the temperature sensor 21 for the high temperature heating water, the temperature sensor 22 for the heating water in the expansion tank, and the temperature sensor 23 for the low temperature heating water are read, and the heating water temperatures Ta, Tb, and Tc are calculated based on these detection signals. Calculate each one.

  Next, in S21, it is determined whether or not the heating water temperature Ta flowing through the high temperature supply passage 11 is approximately the same as the heating water temperature Tb in the expansion tank 16, and the heating water temperature Tb in the expansion tank 16 is low. It is determined whether or not the temperature of the heating water flowing through the supply passage 12 is equal to or higher. When the check valve 19 of the high-temperature branch passage 14 is closed, the high-temperature heating water forms a circulating flow from the high-temperature supply passage 11 through the bypass passage 20 and through the heating return passage 13. No heating water flows through 12, and the temperature of the low-temperature heating terminal 4 does not rise.

  That is, when the heating water temperature Ta flowing through the high temperature supply passage 11 is about the same as the heating water temperature Tb in the expansion tank 16, the heating water temperature Tb in the expansion tank 16 flows through the low temperature supply passage 12. When the heating water temperature is equal to or higher than the temperature Tc, it is determined that the low temperature heating terminal side opening / closing valve 4a is closed, that is, the determination of S21 is Yes, the process proceeds to S22, and the determination of S21 is No, this series End the control.

  Next, in S22, when it is determined that the low temperature heating terminal side opening / closing valve 4a has a closed failure, the user is notified by a display warning, a voice warning, or the like that the low temperature heating terminal side opening / closing valve 4a is in a failure state, This series of control ends.

Next, the operation and effect of the hot water heater 1 of the present invention will be described.
When the high temperature heating terminal 3 and the low temperature heating terminal 4 are operated simultaneously, the hot water heating device 1 determines whether or not the low temperature bypass on / off valve 18 has been opened after the low temperature bypass on / off valve 18 has been controlled to open. When it determines, the control means which changes the heating temperature in the heating heat exchanger 2 to temperature lower than the temperature suitable for the high temperature heating terminal 3 is provided.

  Therefore, when the high temperature heating terminal 3 and the low temperature heating terminal 4 are simultaneously operated by this control means, the low temperature bypass opening / closing valve 18 is controlled to open, but a closed failure occurs due to sticking or disconnection, etc. 18 is not opened, that is, even when the low temperature bypass on / off valve 18 is closed, the heating water heating operation by the heating heat exchanger 2 is lowered and the simultaneous operation is continued to continue the hot water heating operation. Therefore, it is possible to prevent high-temperature heating water from flowing into the low-temperature heating terminal 4 without impairing user convenience, and improve safety.

  Further, the control means is configured such that when the temperature of the heating water flowing through the low temperature supply passage 12 is about the same as the temperature of the heating water flowing through the high temperature supply passage 11, and the temperature of the heating water in the expansion tank 16 is high. When the temperature difference with the temperature of the heating water flowing through the supply passage 11 is equal to or higher than the set temperature, it is determined that there is a closed failure. Therefore, it is possible to determine the closed failure based on the temperature change of the heating water flowing through the low temperature supply passage 12. Further, it is possible to prevent erroneous detection when the heating load is small and the temperature of the heating water returning from the heating load is hardly lowered.

An example in which the embodiment is partially changed will be described.
[1] The failure determination control for determining the closed failure of the low temperature bypass on / off valve 18 in the above embodiment is merely one example. The control method can be adopted.

[2] In addition, those skilled in the art can implement the present invention by adding various modifications without departing from the spirit of the present invention, and the present invention includes such modifications. It is.

DESCRIPTION OF SYMBOLS 1 Hot water heating apparatus 2 Heating heat exchanger 3 High temperature heating terminal 4 Low temperature heating terminal 11 High temperature supply passage 12 Low temperature supply passage 13 Heating return passage 14 High temperature branch passage 15 Low temperature bypass passage 16 Expansion tank 17 Circulation pump 18 Low temperature bypass on-off valve

Claims (2)

A hot water heating apparatus for performing hot water heating by circulatingly supplying heating water heated by a heating heat exchanger to a heating terminal, a high temperature supply passage for supplying high temperature heating water to the high temperature heating terminal, and low temperature heating water A low-temperature supply passage for supplying the heating water to the low-temperature heating terminal, and a heating return passage for returning the heating water from the heating terminal to the heating heat exchanger, the low-temperature supply passage from the high-temperature supply passage A branched high-temperature branch passage is connected to a low-temperature bypass passage branched from a downstream side of a circulation pump installed in the heating return passage and provided with an on-off valve, so that the high-temperature heating terminal and the low-temperature heating terminal can be connected simultaneously. During operation, the on-off valve is opened and the heating temperature in the heating heat exchanger is controlled to a temperature suitable for the high-temperature heating terminal, and the high-temperature heating introduced from the high-temperature branch passage to the low-temperature supply passage Water and said In the hot water heating system is adjusted to the heating water introduced from the hot bypass passage are mixed temperature suitable for the low temperature heating terminal,
During the simultaneous operation, when the opening / closing valve is controlled to be opened and a predetermined time has elapsed, it is determined whether the opening / closing valve is opened, and if it is determined that the opening / closing valve is not opened, the heating heat A hot water heating apparatus comprising control means for changing a heating temperature in the exchanger to a temperature lower than a temperature suitable for the high temperature heating terminal. An expansion tank is installed upstream of the circulation pump in the heating return passage;
When the temperature of the heating water flowing through the low temperature supply passage is approximately the same as the temperature of the heating water flowing through the high temperature supply passage after a predetermined time has elapsed since the opening and closing valve is controlled to open, And when the temperature difference of the temperature of the heating water which flows through the said high temperature supply path and the temperature of the heating water in the said expansion tank is more than preset temperature, it determines with the said on-off valve not being opened, It is characterized by the above-mentioned. The hot water heating apparatus according to claim 1.