JP2015021716A - Hot water storage type hot water supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hot water storage type hot water supply device which can improve heat exchange efficiency by eliminating wasteful combustion of an auxiliary heat source machine, and which can improve operation efficiency of the hot water storage type hot water supply device by effectively utilizing high temperature water in a hot water storage tank water which can be supplied.SOLUTION: A hot water storage type hot water supply device 1 which heats and supplies hot water/water in a hot water storage tank 2 by utilizing an auxiliary heat source machine 3 in the case where a hot water/water temperature in the hot water storage tank decreases includes: a hot water storage tank hot water/water temperature detection sensor 2d for detecting a hot water/water temperature at an upper part of the hot water storage tank 2; a passage hot water/water temperature detection sensor 25 for detecting the hot water/water temperature flowing to an auxiliary heating passage 23 from a tank hot water tapping passage 22; and a control unit 35 which switches a three-way valve 26 capable of switching between the tank hot water tapping passage 22 and the auxiliary heating passage 23 to the auxiliary heating passage 23 side in the case where a detection temperature of the hot water storage tank hot water/water temperature detection sensor 2d becomes equal to or less than a first preset temperature, and which starts combustion of the auxiliary heat source machine 3 in the case where the detection temperature of the passage hot water/water temperature detection sensor 25 becomes equal to or less than a second preset temperature.

Description

  The present invention relates to a hot water storage hot water supply apparatus, and more particularly to an apparatus for reheating hot water using a combustion type auxiliary heat source device when the hot water temperature of a hot water storage tank is lowered.

  2. Description of the Related Art Conventionally, hot water storage and hot water supply apparatuses that generate and store hot water and supply hot water to a desired hot water supply destination have been put to practical use. This type of hot water storage and hot water supply system has a hot water storage tank for storing hot water, various valve members and various pipes, and an auxiliary heat source for reheating when the temperature of the hot water stored in the hot water storage tank is low. Machine, an external case containing these devices, an external heat source machine for generating high-temperature water, and the like.

  When reheating hot water using the auxiliary heat source device, the hot water supply path is generally switched as follows. That is, when the amount of hot water that can be supplied in the hot water storage tank decreases and the temperature of the hot water in the upper part of the hot water storage tank decreases, the hot water tank bypasses the auxiliary heat source unit and is connected directly to the hot water supply destination. Switching to the passage through the auxiliary heat source machine, driving the auxiliary heat source machine, reheating hot water and supplying hot water.

  For example, in the water heater shown in FIG. 4 of Patent Document 1, a hot water storage tank, a supply water channel connected to a desired hot water supply destination, and a heating device (auxiliary heat source) that reheats when the amount of stored hot water in the hot water storage tank decreases. A heating channel connected to the supply channel from the hot water storage tank via the auxiliary heat source unit, a bypass channel connected to the supply channel by bypassing the auxiliary heat source unit from the hot water storage tank, a heating channel and a bypass channel The structure provided with the distribution valve etc. which were installed in the branch part of this is disclosed.

  In the water heater of Patent Document 1 described above, when there is a sufficient amount of stored hot water in the hot water storage tank, the heating water channel is fully closed by the distribution valve and the bypass water channel is fully opened to store the hot water in the hot water storage tank. When the value is below the reference value, first, both the heating channel and the bypass channel are opened by the distribution valve, the water remaining in the heating channel is discharged, and the heating channel is fully opened after a predetermined time has elapsed. In addition, a technique is disclosed in which a rapid temperature change of hot water is prevented by operating the heating device after the bypass channel is fully closed.

Japanese Patent No. 5175138

  By the way, in the water heater of patent document 1, although the heating apparatus is operated after discharging the residual water of a heating water channel, the length and diameter of the existing piping used for a water heater are considered for the residual water of a heating water channel. Since the amount is often small, when the heating device is operated after a predetermined time has passed, the upper part of the hot water tank (from the part where the hot water temperature detection sensor for detecting the hot water temperature in the upper part of the hot water tank is installed) Also, there is a possibility that hot water that can be supplied with hot water remains between the upper part) and the branch part between the heating channel and the bypass channel.

  However, if combustion of the auxiliary heat source unit is started with high temperature water remaining from the upper part of the hot water storage tank to the branch part, the hot water that can be supplied with hot water will be heated by the auxiliary heat source unit. In addition, the high-temperature water is wasted, and the heat exchange efficiency (combustion efficiency) of the auxiliary heat source machine is reduced. As a result, the operation efficiency of the hot water storage hot-water supply apparatus is reduced, resulting in a problem of lack of energy saving.

  It is an object of the present invention to improve the heat exchange efficiency by eliminating wasteful combustion of an auxiliary heat source machine in a hot water storage hot water supply apparatus, and to operate the hot water storage hot water supply apparatus by effectively using hot water that can be supplied with hot water in a hot water storage tank. It is to provide something that can improve efficiency.

  The hot water storage and hot water supply apparatus according to claim 1 includes a tank hot water passage connected from the upper part of the hot water storage tank to the hot water supply passage, an auxiliary heating passage branched from the tank hot water passage and connected to a combustion type auxiliary heat source device, and the auxiliary heat source. An auxiliary heat source machine hot water passage connected from the machine to the hot water supply passage, and switching means capable of switching between the tank hot water passage and the auxiliary heating passage, and the auxiliary heat source when the hot water temperature of the hot water storage tank is lowered In the hot water storage hot water supply apparatus for heating and supplying hot water in the hot water storage tank using a machine, the auxiliary temperature detection means for detecting the hot water temperature in the upper part of the hot water storage tank, and the auxiliary heating from the tank hot water outlet passage Auxiliary heating temperature detecting means for detecting the temperature of hot water flowing in the passage, and the switching means when the detected temperature of the upper temperature detecting means is equal to or lower than a first set temperature. Switched to hot aisle, if the detected temperature of the auxiliary heating temperature detecting means is equal to or less than a second set temperature, is characterized by comprising an auxiliary heat source apparatus control means for starting the combustion of the auxiliary heat source unit.

  According to a second aspect of the present invention, there is provided the hot water storage hot water supply apparatus according to the first aspect, wherein the auxiliary heating temperature detecting means is installed upstream of a branching portion of the tank outlet passage where the auxiliary heating passage branches. Yes.

  According to the invention of claim 1, the upper temperature detecting means for detecting the temperature of the hot water in the upper part of the hot water storage tank, and the auxiliary heating temperature detecting means for detecting the temperature of the hot water flowing from the tank outlet passage to the auxiliary heating passage. When the detected temperature of the upper temperature detecting means is lower than the first set temperature, the switching means is switched to the auxiliary heating passage side, and when the detected temperature of the auxiliary heating temperature detecting means is lower than the second set temperature, Since the auxiliary heat source machine control means for starting combustion of the auxiliary heat source machine is provided, the hot water temperature at the upper part in the hot water storage tank and the hot water temperature flowing from the tank outlet passage to the auxiliary heating passage by the auxiliary heat source machine control means are two places. As the temperature decreases, the auxiliary heat source machine can start to burn.

  Therefore, even if it is determined that the hot water temperature in the upper part of the hot water storage tank is lowered and reheating of the hot water by the auxiliary heat source unit is necessary, the hot water temperature flowing from the tank hot water passage to the auxiliary heating passage is lowered until the hot water temperature in the hot water storage tank is It is possible to supply hot water to the hot water supply passage without reheating the hot water that can be supplied by the auxiliary heat source device. Therefore, by eliminating wasteful combustion of the auxiliary heat source unit, the heat exchange efficiency of the auxiliary heat source unit is improved, energy saving is also improved, and hot water that can be supplied in the hot water storage tank is used as effectively as possible. The operating efficiency of the hot water supply device is improved.

  According to the second aspect of the present invention, the auxiliary heating temperature detecting means is installed on the upstream side of the branch portion where the auxiliary heating passage of the tank hot water passage branches, so that the hot water is discharged from the upper portion of the hot water storage tank to the tank hot water passage. By detecting the hot water temperature immediately after the hot water, the hot water remaining in the hot water storage tank can be used as much as possible, and the operating efficiency of the hot water storage hot water supply device is further improved.

It is a schematic block diagram of the hot water storage hot-water supply apparatus which concerns on the Example of this invention. It is a flowchart of hot water supply operation control.

  Hereinafter, modes for carrying out the present invention will be described based on examples.

First, the whole structure of the hot water storage hot-water supply apparatus 1 of this invention is demonstrated.
As shown in FIG. 1, a hot water storage and hot water supply apparatus 1 has functions such as hot water storage, hot water supply, hot water supply to a hot water heating terminal such as a floor heating panel, etc., and a tank unit 1A including a hot water storage tank 2, a hot water storage An external heat source device 10 for heating hot water in the tank 2 and a hot water circulation circuit 6 for connecting the tank unit 1A and the external heat source device 10 are provided.

  The tank unit 1A includes a hot water storage tank 2, an auxiliary heat source unit 3, a heat exchanger 4 for heating, a water supply path 5, a hot water circulation circuit 6, a hot water supply path 7, a hot water heating circuit 8 for supplying heating water to a floor heating panel, etc. A heat-utilizing circuit 9 for heating the heating water of the heating circuit 8 and the like are provided, and most of them are integrally stored in the outer case 11. As the external heat source unit 10, a heat pump type heat source unit, an exhaust heat recovery heat exchanger of a fuel cell power generation unit, or the like is used.

Next, the hot water storage tank 2 will be described.
As shown in FIG. 1, the hot water storage tank 2 is composed of a sealed tank capable of storing high-temperature water (for example, 80 to 90 ° C.) heated by the external heat source unit 10, in order to prevent heat dissipation of the stored hot water. The tank is covered with insulation.

  On the outer periphery of the hot water storage tank 2, hot water storage tank hot water temperature detection sensors 2a to 2d are provided in order at equal intervals from the lower side to the upper side, and the hot water storage tank 2 is provided with hot water temperature detection sensors 2a to 2d. The temperature of the hot water in the plurality of reservoirs is detected. Of the plurality of hot water storage tank hot water temperature detection sensors 2a to 2d, the uppermost hot water storage tank hot water temperature detection sensor 2d serves as an upper temperature detection means for detecting the upper hot water temperature in the hot water storage tank 2 of the present invention. It is equivalent.

  The auxiliary heat source unit 3 is composed of a known gas water heater that incorporates a burner, a heat exchanger, and the like. The auxiliary heat source unit 3 is heated only when a command is transmitted from the control unit 35 in response to a special case such as when the hot water temperature in the hot water storage tank 2 is lowered, and heats the hot water.

  The heating heat exchanger 4 heats the heating water flowing through the hot water heating circuit 8, and the heat exchange passage portion 4 a that is a part of the heat utilization circulation circuit 9 and the heat that is a part of the hot water heating circuit 8. And an exchange passage portion 4b. In the heating heat exchanger 4, heat is exchanged between the high-temperature water flowing in the heat utilization circulation circuit 9 and the heating water flowing in the hot water heating circuit 8, and the heating water is heated.

Next, the water supply path 5 will be described.
As shown in FIG. 1, the water supply path 5 supplies low temperature clean water from a water supply source to the hot water storage tank 2, and has an upstream water supply passage part 5a, an intermediate water supply passage part 5b, and a downstream water supply passage part 5c. ing. An upstream end of the upstream water supply passage portion 5 a is connected to a water source, and a downstream end of the downstream water supply passage portion 5 c is connected to a lower portion of the hot water storage tank 2. A bypass passage 12 connected to the hot water supply passage 7 is branched from between the upstream water supply passage 5a and the intermediate water supply passage 5b. An open / close valve 5e is installed in the upstream water supply passage 5a, and the open / close valve 5e is normally opened so that low-temperature hot water is supplied into the hot water storage tank 2. A check valve 5d is installed in the intermediate water supply passage 5b, and a check valve 12a is installed in the bypass passage 12.

  A bypass passage 14 connected to the heat utilization circuit 9 is branched from between the intermediate water supply passage 5b and the downstream water supply passage 5c, and a heat storage switching valve 15 is installed at this branch. By this bypass passage 14, low temperature clean water can be supplied to the heat utilization circuit 9, and conversely, hot water can be returned from the heat utilization circuit 9 to the hot water storage tank 2. A drainage passage 31 connected to the outside is branched from the downstream water supply passage portion 5c, and a manual or automatic drainage valve 32 for draining the hot water storage tank 2 is installed in the drainage passage 31, and usually a drainage valve 32 is provided. Is closed.

Next, the hot water circulation circuit 6 will be described.
As shown in FIG. 1, the hot water circulation circuit 6 is a closed circuit that heats hot water by circulating it between the hot water storage tank 2 and the external heat source unit 10. It has a passage portion 6b, a downstream low temperature side circulation passage portion 6c, an upstream high temperature side circulation passage portion 6d, an outside unit high temperature side circulation passage portion 6e, a downstream high temperature side circulation passage portion 6f, and the like. The upstream end of the upstream low temperature side circulation passage portion 6 a is connected to the lower portion of the hot water storage tank 2, and the downstream end of the downstream high temperature side circulation passage portion 6 f is connected to the upper portion of the hot water storage tank 2.

  The upstream low temperature side circulation passage portion 6 a and the downstream high temperature side circulation passage portion 6 f are installed in the outer case 11. A branch passage portion 16 connected from the upstream low temperature side circulation passage portion 6a to the downstream high temperature side circulation passage portion 6f is branched, and the branch portion includes a circulation circuit including the hot water storage tank 2 and a circulation circuit bypassing the hot water storage tank 2. A three-way valve 17 that can alternatively be selected is provided. A circulation pump 18 is installed on the downstream side of the three-way valve 17 in the upstream low temperature side circulation passage portion 6a.

  The downstream low-temperature side circulation passage portion 6 c and the upstream high-temperature side circulation passage portion 6 d are installed in the exterior case 10 a of the external heat source device 10. A heat exchanging portion 10b of the external heat source device 10 is provided between the downstream low temperature side circulation passage portion 6c and the upstream high temperature side circulation passage portion 6d.

  A pair of joints 19 a and 19 b are installed in the outer case 11, and a pair of joints 19 c and 19 d are also installed in the outer case 10 a of the external heat source device 10. Both ends of the low temperature side circulation passage 6b outside the unit are connected to joints 19a and 19c, and both ends of the high temperature side circulation passage 6e outside the unit are connected to joints 19b and 19d. Each of the joints 19a to 19d is provided with a drain plug.

Next, the hot water supply path 7 will be described.
As shown in FIG. 1, the hot water supply path 7 supplies hot water stored in the hot water storage tank 2 to a desired hot water supply destination such as a bath. The hot water supply passage 21 connected to the hot water tap and the hot water storage tank 2 are connected to each other. A tank hot water passage 22 connected to the hot water supply passage 21 from above, an auxiliary heating passage 23 branched from the tank hot water passage 22 and connected to the combustion type auxiliary heat source device 3, and connected to the hot water supply passage 21 from the auxiliary heat source device 3. The auxiliary heat source machine hot water outlet passage 24 and the like are provided.

  The hot water supply passage 21 has an upstream hot water supply passage portion 21a through which high-temperature water flows and a downstream hot water supply passage portion 21b through which mixed hot water flows, and the upstream end of the upstream hot water supply passage portion 21a is connected to the downstream end of the tank outlet hot water passage 22, The downstream end of the passage portion 21b is connected to the hot water tap. A mixing valve 25 is installed between the upstream hot water supply passage portion 21a and the downstream hot water supply passage portion 21b. A bypass passage portion 12 branched from the water supply path 5 is connected to the mixing valve 25. The mixing valve 25 controls the mixing ratio of water and high temperature water so that the tapping temperature becomes the command temperature. A flow rate sensor 21c is installed in the downstream hot water supply passage 21b.

  The tank outlet 22 has an upper outlet hot water passage 22a and a lower outlet hot water passage 22b. The upstream end of the upper outlet hot water passage 22a is connected to the upper part of the hot water storage tank 2 and is downstream of the lower outlet hot water passage 22b. The end is connected to the upstream end of the upstream hot water supply passage 21a. An auxiliary heating passage 23 is branched from between the upper effluent passage portion 22a and the lower effluent passage portion 22b. A passage hot water for detecting the temperature of hot water flowing from the tank hot water passage 22 to the auxiliary heating passage 23 is upstream of the branching portion of the auxiliary hot water passage 23 of the tank hot water passage 22 and upstream of the upper hot water passage passage portion 22a. A temperature detection sensor 25 (corresponding to auxiliary heating temperature detection means) is installed.

  The auxiliary heating passage 23 has an upstream heating passage portion 23a and a downstream heating passage portion 23b, the upstream end of the upstream heating passage portion 23a is connected to the tank outlet passage 22, and the downstream end of the downstream heating passage portion 23b is an auxiliary heat source machine. 3 is connected to the inlet. Between the upstream heating passage portion 23a and the downstream heating passage portion 23b, a three-way valve 26 (corresponding to switching means) capable of switching between the tank hot water passage 22 and the auxiliary heating passage 23 is installed. The three-way valve 26 is also connected to the downstream end of the hot water return side passage portion 9b of the heat utilization circuit 9. This three-way valve 26 can switch connection / disconnection between the upstream heating passage portion 23a and the downstream heating passage portion 23b and connection / disconnection between the downstream heating passage portion 23b and the hot water return side passage portion 9b. is there. A pressure feed pump 27 is installed in the downstream heating passage portion 23b.

  The auxiliary heat source machine outlet passage 24 has an upstream auxiliary outlet passage portion 24a and a downstream auxiliary outlet passage portion 24b, and the upstream end of the upstream auxiliary outlet passage portion 24a is connected to the outlet of the auxiliary heat source unit 3, and the downstream auxiliary outlet passage The downstream end of the portion 24b is connected to the upstream end of the upstream hot water supply passage portion 21a. A hot water / outward side passage portion 9a of the heat utilization circulation circuit 9 is branched from between the upstream auxiliary hot water passage portion 24a and the downstream auxiliary hot water passage portion 24b. A tank water proportional valve 28 is provided in the downstream auxiliary hot water passage portion 24b.

Next, the hot water heating circuit 8 will be described.
As shown in FIG. 1, the hot water heating circuit 8 is a circuit that circulates heating water supplied to a floor heating panel, a bathroom dryer, and the like, and has a heating return side passage portion 8a and a heating forward side passage portion 8b. ing. The heat exchange passage portion 4b of the heating heat exchanger 4 is installed between the heating return side passage portion 8a and the heating outgoing side passage portion 8b.

Next, the heat utilization circulation circuit 9 will be described.
As shown in FIG. 1, the heat utilization circuit 9 is a closed circuit that circulates hot water and exchanges heat with the hot water heating circuit 8, and includes a hot water going-side passage portion 9 a, a hot water return side passage portion 9 b, A downstream heating passage portion 23 b of the auxiliary heating passage 23 and an upstream auxiliary hot water passage portion 24 a of the auxiliary heat source machine hot water passage 24 are provided. A heat exchange passage portion 4a of the heat exchanger 4 for heating is connected between the hot water going side passage portion 9a and the hot water return side passage portion 9b.

Next, the control unit 35 will be described.
As shown in FIG. 1, the hot water storage and hot water supply device 1 is controlled by a control unit 35. Detection signals of various sensors are transmitted to the control unit 35, and the control unit 35 controls the operation of the hot water storage and hot water supply device 1, the operation / stop of various pumps, the switching of the open / close states of various valves, and the opening degree adjustment. Then, various operations (hot water supply operation, hot water heating operation, heating operation, drainage operation, etc.) are executed.

  Next, hot water supply operation control using the auxiliary heat source unit 3 will be described based on the flowchart of FIG. In the figure, the symbol Si (i = 1, 2,...) Indicates each step. The control program for the hot water supply operation control is stored in the control unit 35 in advance.

  In the flowchart of FIG. 2, when this control is started, first, in S1, it is determined whether or not a hot water supply operation start condition is satisfied based on a user operation and detection signals of various sensors. When the determination of S1 is Yes, that is, when the condition for starting the hot water supply operation is satisfied, the process proceeds to S2, and S1 is repeated while the determination of S1 is No.

  Next, in S2, a hot water supply operation is started, and the process proceeds to S3. That is, with the opening of the hot water tap, hot water is pushed out from the upper part of the hot water storage tank 2 to the tank hot water passage 22 by the hot water pressure applied to the hot water storage tank 2, and this hot water passes through the tank hot water supply passage 22 to the hot water supply passage 21. The temperature is adjusted by mixing with low temperature clean water in the mixing valve 25, and the temperature-adjusted hot water is supplied from the hot water tap.

  Next, in S3, the detection signal of the hot water storage tank hot water temperature detection sensor 2d is read, and based on this detection signal, the hot water temperature (detection temperature) Ta stored in the upper part of the hot water storage tank 2 is calculated. Migrate to

  Next, in S4, it is determined whether or not the hot water temperature Ta in the upper part of the hot water storage tank 2 is equal to or lower than a first set temperature obtained by adding a predetermined set temperature α (for example, 5 ° C.) to a set temperature for hot water supply (for example, 40 ° C.). . When the determination of S4 is Yes, that is, when the amount of hot water in the hot water storage tank 2 is reduced and the hot water remains in the hot water storage tank 2 only for the volume above the hot water storage tank hot water temperature detection sensor 2d, The process proceeds to S5.

  If the determination in S4 is No, that is, if sufficient hot water remains in the hot water storage tank 2, the process proceeds to S6 to determine whether or not the hot water supply operation end condition is satisfied. When determination of S6 is Yes, it transfers to S12 and a hot water supply driving | operation is complete | finished. When the determination of S6 is No, that is, when the hot water supply operation is continued, the process proceeds to S3, and S3 and S4 are repeatedly executed.

  Next, in S5, when the hot water temperature Ta becomes equal to or lower than the first set temperature, the control unit 35 sets the hot water storage hot water supply device 1 to the combustion preparation mode. That is, the three-way valve 26 is switched to the auxiliary heating passage 23 side (connection between the upstream heating passage portion 23a and the downstream heating passage portion 23b), the tank water proportional valve 28 is closed (maximum throttled state), and the heat storage switching valve 15 Is switched to open to the bypass passage portion 14 side (connection between the bypass passage portion 14 and the downstream water supply passage portion 5c), the pressure feed pump 27 is driven, and the auxiliary heat source unit 3 is prepared for combustion (the fan is driven to unburn the combustion chamber). A pre-purge) is performed by exhausting gas or the like to bring it into a state immediately before ignition, and the process proceeds to S7.

  In S5, since the hot water for the upper volume from the hot water storage tank hot water temperature detection sensor 2d in the hot water storage tank 2 maintains a temperature at which hot water can be supplied exceeding the first set temperature, the auxiliary heat source unit 3 is operated (combustion). The hot water can be supplied without reheating.

  Therefore, in the combustion preparation stage of S5, the hot water discharged from the upper part of the hot water storage tank 2 flows through the lower effluent hot water passage portion 22b and is supplied to the hot water supply passage 21. It flows from the passage portion 22a to the auxiliary heating passage 23, and flows into the upstream auxiliary hot water passage portion 24a via the auxiliary heat source unit 3 in the combustion preparation state. Since the tank water proportional valve 28 is squeezed as much as possible, the residual water in the auxiliary heating passage 23, the auxiliary heat source unit 3, and the upstream auxiliary hot water passage portion 24a is pushed out to the hot water from the hot water storage tank 2, and the hot water going side passage portion. 9a, the hot water return side passage portion 9b, the bypass passage portion 14, and the downstream water supply passage portion 5c are returned to the lower portion of the hot water storage tank 2. Since the tank water proportional valve 28 is throttled, a small amount of hot water from the hot water storage tank 2 flows from the upstream auxiliary hot water passage portion 24a to the downstream auxiliary hot water passage portion 24b.

  Thus, in the combustion preparation stage of S5, the hot water temperature of the upstream auxiliary hot water passage portion 24a and the auxiliary hot water hot water passage portion 24a is increased, so that the auxiliary heat source machine 3 starts the combustion from the auxiliary heat source machine hot water passage 24 to the hot water supply passage 21. In addition, since the auxiliary heat source device 3 is in a state immediately before ignition, the hot water that can be supplied with hot water is used up and the low temperature hot water flows into the auxiliary heat source device 3 so that it ignites immediately. Therefore, deterioration of hot water supply characteristics can be prevented.

  Next, in S7, the detection signal of the passage hot water temperature detection sensor 25 is read, and based on this detection signal, the hot water temperature (detection temperature) Tb flowing through the upper outlet water passage portion 22a of the tank outlet passage 22 is calculated, The process proceeds to S8.

  Next, in S8, it is determined whether or not the hot water temperature Tb flowing through the upper outlet water passage portion 22a of the tank hot water passage 22 is equal to or lower than a second set temperature obtained by adding a predetermined set temperature β (for example, 1 ° C.) to the hot water set temperature. To do. When the determination of S8 is Yes, that is, when the hot water for the upper volume is discharged from the hot water storage tank hot water temperature detection sensor 2d in the hot water storage tank 2 and the hot water temperature Tb of the tank hot water discharge passage 22 is lowered, the process goes to S9. Transition.

  If the determination in S8 is No, that is, if hot water that can be supplied with hot water remains in the hot water storage tank 2, the process proceeds to S10, where it is determined whether the hot water supply operation end condition is satisfied, and the determination in S10 is made. In the case of Yes, it transfers to S12 and completes the hot water supply operation. When the determination of S8 is No, that is, when the hot water supply operation is continued, the process proceeds to S7, and S7 and S8 are repeatedly executed.

  Next, in S9, when the hot water temperature Tb becomes equal to or lower than the second set temperature, the control unit 35 sets the hot water storage hot water supply device 1 to the combustion start mode. That is, the heat storage switching valve 15 is switched to the bypass passage portion 14 side closed (connection cutoff between the bypass passage portion 14 and the downstream water supply passage portion 5c), the tank water proportional valve 28 is opened, and the auxiliary heat source unit 3 is started to burn. , S11 is entered. That is, hot water that can be supplied with hot water is discharged from the upper part of the hot water storage tank 2 and hot water that exceeds the second set temperature flows through the upper effluent hot water passage 22a, but the amount of this hot water gradually decreases. Therefore, when the hot water temperature Tb gradually decreases and becomes equal to or lower than the second set temperature, the combustion start mode is set. Then, the hot water discharged from the hot water storage tank 2 flows through the auxiliary heating passage 23 almost without flowing through the lower effluent hot water passage portion 22b, is heated by the auxiliary heat source unit 3, and the heated hot water (for example, 75 degrees) is supplied as the auxiliary heat source. It flows through the machine outlet passage 24 and flows into the hot water supply passage 21.

  In S11, it is determined whether or not the hot water supply operation termination condition is satisfied. If the determination in S11 is No, the determination in S11 is repeated. If the determination in S11 is Yes, the process proceeds to S12 to end the hot water supply operation. The control unit 35, the control programs S3 to S9, and the like correspond to the auxiliary heat source machine control means of the present invention.

Next, the operation and effect of the hot water storage and hot water supply apparatus 1 of the present invention will be described.
The hot water storage and hot water supply device 1 includes a hot water storage tank hot water temperature detection sensor 2d for detecting the hot water temperature in the upper part of the hot water storage tank 2, and a hot water temperature of a passage for detecting the temperature of the hot water flowing from the tank hot water discharge passage 22 to the auxiliary heating passage 23. When the detection temperature of the detection sensor 25 and the hot water storage tank hot water temperature detection sensor 2d is equal to or lower than the first set temperature, the three-way valve 26 is switched to the auxiliary heating passage 23 side, and the detection temperature of the passage hot water temperature detection sensor 25 is the first. Since the control unit 35 (auxiliary heat source unit control means) for starting the combustion of the auxiliary heat source unit 3 when the temperature becomes equal to or lower than the preset temperature is provided, the control unit 35 controls the temperature of the hot water in the upper part of the hot water storage tank 2 and the tank. Combustion of the auxiliary heat source unit 3 can be started in accordance with a decrease in the hot water temperature at two locations of the hot water temperature flowing from the hot water passage 22 to the auxiliary heating passage 23.

  Therefore, even when the hot water temperature in the upper part of the hot water storage tank 2 is lowered and it is determined that the hot water needs to be reheated by the auxiliary heat source unit 3, the hot water temperature flowing from the tank hot water passage 22 to the auxiliary heating passage 23 is lowered. The hot water in the hot water storage tank 2 that can supply hot water can be supplied to the hot water supply passage 21 without being reheated by the auxiliary heat source unit 3. Therefore, by eliminating wasteful combustion of the auxiliary heat source unit 3, heat exchange efficiency of the auxiliary heat source unit 3 is improved, energy saving is also improved, and hot water that can be supplied with hot water in the hot water storage tank 2 is used as effectively as possible. Thus, the operation efficiency of the hot water storage hot water supply apparatus 1 is improved.

  Further, since the passage hot water temperature detection sensor 25 is installed upstream of the branch portion where the auxiliary heating passage 23 of the tank hot water passage 22 branches, immediately after the hot water is discharged from the upper part of the hot water storage tank 2 to the tank hot water passage 22. By detecting the hot water temperature, hot water remaining in the hot water storage tank 2 can be used as much as possible, and the operating efficiency of the hot water hot water supply apparatus 1 is further improved.

Next, a mode in which the above embodiment is partially changed will be described.
[1] In the above-described embodiment, the three-way valve 26 is installed in the downstream heating passage portion 23b of the auxiliary heating passage 23, but it is not particularly limited to this structure. You may install the three-way valve 26 in the branched part which branched.

[2] In the above embodiment, the passage hot water temperature detection sensor 25 is installed in the upper outlet water passage portion 22 a of the tank hot water passage 22, but it is not particularly limited to this structure. You may install in the upstream of the valve 26. FIG.

[3] In the above-described embodiment, the first and second set temperatures are merely examples. If the first and second set temperatures do not fall below the temperature at which hot water can be supplied, the first and second set temperatures are used. Can be appropriately changed.

[4] 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 storage hot water supply equipment 2 Hot water storage tank 2d Hot water storage tank hot water temperature detection sensor 3 Auxiliary heat source machine 10 External heat source machine 21 Hot water supply passage 22 Tank hot water supply passage 23 Auxiliary heating passage 24 Auxiliary heat source machine hot water supply passage 25 Passage hot water temperature detection sensor 26 Three-way valve 27 Pump 35 control unit

Claims (2)

A tank hot water passage connected from the upper part of the hot water storage tank to the hot water supply passage, an auxiliary heating passage branched from the tank hot water passage and connected to the combustion type auxiliary heat source device, and connected from the auxiliary heat source device to the hot water supply passage An auxiliary heat source machine hot water outlet passage, and a switching means capable of switching between the tank hot water outlet passage and the auxiliary heating passage, and when the hot water temperature of the hot water storage tank decreases, the auxiliary heat source device is used to In hot water storage hot water supply equipment that heats hot water and supplies hot water,
Upper temperature detecting means for detecting the temperature of hot water in the upper part of the hot water storage tank, auxiliary heating temperature detecting means for detecting the temperature of hot water flowing from the tank outlet passage to the auxiliary heating passage, and the upper temperature detecting means When the detected temperature of the auxiliary heating temperature is lower than the first set temperature, the switching means is switched to the auxiliary heating passage side, and when the detected temperature of the auxiliary heating temperature detecting means is lower than the second set temperature, the auxiliary An auxiliary heat source machine control means for starting combustion of the heat source machine. The hot water storage and hot water supply apparatus according to claim 1, wherein the auxiliary heating temperature detecting means is installed upstream of a branching portion of the tank hot water passage where the auxiliary heating passage branches.