JP2015158322A - Hot water storage and supply system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hot water storage and supply system that enables consumption of intermediate temperature water in a hot water storage tank during a hot water filling operation and recovery of waste heat of a heat source machine .SOLUTION: A hot water storage and supply system 1 includes: an outside heat source machine 2; a hot water storage tank 4; a waste heat recovery circulation circuit 15 for recovering waste heat of the outside heat source machine 2 by using hot water in the hot water storage tank 4; an auxiliary heat source machine 5 for reheating the hot water in the hot water storage tank 4; a hot water filling passage 11 for supplying the hot water in the hot water storage tank 4 to a bathtub; and a bath reheating circuit 12 for reheating bathtub water in the bathtub 10. The hot water storage and supply system 1 further includes a control unit 45 that performs filling of hot water by: mixing the hot water in the hot water storage tank 4 with low temperature water to make an adjustment to a first set temperature if a temperature of the hot water in the hot water storage tank 4 exceeds the first set temperature; prohibiting an operation of the auxiliary heat source machine 5 if the temperature is equal to or lower than the first set temperature and equal to or higher than a second set temperature; and heating the hot water in the hot water storage tank 4 by the auxiliary heat source machine 5 if the temperature is below the second set temperature, when filling of hot water from the hot water storage tank 4 in the bathtub 10 is performed.

Description

  The present invention relates to a hot water storage and hot water supply system, and more particularly to a system for recovering waste heat generated secondary from an external heat source machine such as a fuel cell or a gas engine.

  Conventionally, a cogeneration system has been put to practical use in which the total energy efficiency is improved by collecting and reusing exhaust heat from an internal heat source machine or an external heat source machine. Various types of cogeneration systems that recover exhaust heat from fuel cells, gas engines, and the like have been put into practical use.

  For example, a fuel cell cogeneration system is a fuel cell power generation system that generates electric power by converting chemical energy into electric energy by an oxidation-reduction reaction between air and reformed fuel gas (hydrogen-containing gas), and the fuel cell power generation system. It consists of a hot water storage hot water system that recovers and stores the exhaust heat of the exhaust gas that is generated secondaryly during power generation as hot water, a waste heat recovery circuit that connects the fuel cell power generation system and the hot water storage hot water system, etc. Yes.

  In the fuel cell power generation system described above, so-called water self-sustained operation is performed in which the condensed water generated by cooling the exhaust gas by the exhaust heat recovery heat exchanger is reused. Normally, hot water from the hot water storage hot water system is circulated in the exhaust heat recovery circuit, heat is exchanged between the hot water and exhaust gas in the exhaust heat recovery heat exchanger, and the water vapor contained in the exhaust gas is cooled and condensed. After collecting the water and purifying the condensed water, it is temporarily stored and then reused for power generation.

  In addition, a hot water storage and hot water system that collects and stores exhaust heat includes a hot water storage tank that stores hot water, an auxiliary heat source device that reheats the hot water stored in the hot water storage tank, various valve members, various piping, and the like. It has functions such as hot water storage, hot water supply, hot water supply to hot water heating terminals such as floor heating panels, hot water supply to a bath, and reheating. The auxiliary heat source unit is used for heating hot water in a hot water supply operation when the hot water in the hot water storage tank is lower than the hot water supply set temperature. Cogeneration systems incorporating an auxiliary heat source device are disclosed in various documents.

  For example, a heat utilization device (cogeneration system) disclosed in Patent Document 1 includes a heat source device, a hot water storage tank that stores the heat generated by the heat source device as hot water, and a control unit that controls the entire heat utilization device. It consists of a unit, an auxiliary heat source device composed of a gas water heater, and the like. In the heat utilization apparatus disclosed in Patent Document 1, when the control unit acquires setting information such as a hot water operation or an additional hot water operation, the hot water is heated by prohibiting the hot water from being heated by the auxiliary heat source machine.

Japanese Patent No. 5122850

  By the way, when intermediate temperature water (for example, about 30 to 40 ° C.) having a temperature lower than the hot water supply set temperature is stored in the upper part of the hot water storage tank, if this intermediate temperature water is reheated by the auxiliary heat source machine, There is a problem that the temperature adjustment becomes difficult due to the excessively high temperature. Conventionally, the temperature is adjusted by mixing low-temperature clean water with the medium-temperature water before flowing into the auxiliary heat source machine from the hot water storage tank to lower the hot water temperature, and then performing reheating with the auxiliary heat source machine.

  However, in such a conventional control method, since the low temperature clean water is mixed with the medium temperature water, the medium temperature water is not efficiently consumed, and there is a possibility that a large amount of the medium temperature water remains in the hot water storage tank. If this medium temperature water is used for exhaust heat recovery, problems such as deterioration of the efficiency of exhaust heat recovery and a decrease in the amount of condensed water generated may occur. In addition, in the heat utilization device of Patent Document 1, the operation of the auxiliary heat source machine is prohibited and hot water in the hot water storage tank is mixed and adjusted with cold clean water to supply hot water. There is a risk that medium temperature water will remain.

  An object of the present invention is to provide a hot water storage hot water supply system that can actively consume hot water in the hot water storage tank during hot water operation, and that improves the efficiency of exhaust heat recovery of the heat source unit. is there.

  The hot water storage and hot water supply system according to claim 1 includes a heat source device, a hot water storage tank, an exhaust heat recovery circuit that recovers exhaust heat of the heat source device using hot water in the hot water storage tank, and reheats the hot water in the hot water storage tank. A hot water storage and hot water supply system comprising: an auxiliary heat source that performs heat supply, a pouring passage for supplying hot water from the hot water storage tank to the bathtub, and a bath remedy circuit for pursuing the bathtub water in the bathtub. When the hot water in the hot water storage tank exceeds the first set temperature, the hot water in the hot water storage tank is mixed with low-temperature water to adjust the first set temperature to supply hot water, and the hot water in the hot water storage tank is When the temperature is equal to or lower than the first set temperature and equal to or higher than the second set temperature, the hot water in the hot water storage tank is mixed with low-temperature water and adjusted to the second set temperature or lower, and then reheated by the auxiliary heat source device. And adjust to the first set temperature to supply hot water. When the hot water in the hot water storage tank is lower than the second set temperature, in the hot water storage and hot water system for supplying hot water by reheating the hot water in the hot water storage tank with the auxiliary heat source machine and adjusting to the first set temperature, When performing hot water filling from the hot water storage tank to the bathtub, if the hot water in the hot water storage tank exceeds a first set temperature, the hot water in the hot water storage tank is mixed with low-temperature water and the first set temperature. When the hot water in the hot water storage tank is lower than the first set temperature and higher than the second set temperature, the auxiliary heat source machine is prohibited from being operated and hot water is filled. When the hot water in the hot water storage tank falls below the second set temperature, the hot water storage tank is provided with control means for heating the hot water in the hot water storage tank with the auxiliary heat source device.

  According to the first aspect of the present invention, the hot water storage and hot water system cools the hot water in the hot water storage tank when the hot water from the hot water storage tank exceeds the first set temperature when the hot water is filled from the hot water storage tank to the bathtub. Mixing with water and adjusting to the first set temperature to fill the water, and if the hot water in the hot water storage tank is below the first set temperature and above the second set temperature, the operation of the auxiliary heat source is prohibited. When the hot water filling is carried out and the hot water in the hot water storage tank falls below the second set temperature, the hot water in the hot water storage tank is heated by the auxiliary heat source device and the hot water filling is provided. Hot water that is lower than the set temperature and higher than the second set temperature is used directly for hot water filling without adjusting the temperature.

  Accordingly, when hot water is filled, hot water that is lower than the first set temperature and higher than the second set temperature stored in the hot water storage tank can be actively consumed, so that the hot water temperature in the hot water storage tank is efficiently reduced. Thus, the efficiency of exhaust heat recovery of the heat source machine is improved. When the heat source device is a fuel cell, the amount of condensed water generated increases, and the operating efficiency of the fuel cell cogeneration system improves.

  In addition, since hot water that is lower than the first set temperature of the hot water storage tank and higher than the second set temperature is actively consumed, the hot water in the hot water storage tank is heated by an auxiliary heat source device, and the hot water is filled. Hot water filling that is almost the same as tensioning operation is possible.

It is a schematic block diagram of the hot water storage hot-water supply system at the time of hot water filling operation which prohibited the operation | movement of the auxiliary heat source machine which concerns on the Example of this invention. It is a schematic block diagram of the hot water storage hot-water supply system at the time of the hot water filling operation by heating of an auxiliary heat source machine. It is a schematic block diagram of the hot water storage hot-water supply system at the time of a chasing operation. It is a flowchart of the first half part of hot water filling operation control. It is a flowchart of the latter half part of hot water filling 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 system 1 of this invention is demonstrated.
As shown in FIG. 1 to FIG. 3, the hot water storage hot water system 1 has functions such as hot water storage, hot water supply, hot water supply and reheating to a bath, hot water supply to a hot water heating terminal such as a floor heating panel, and the like. An external heat source device 2, a tank unit 3, an exhaust heat recovery circuit 15 for connecting the tank unit 3 and the external heat source device 2, a control unit 45, and the like are provided.

  As the external heat source unit 2 (corresponding to a heat source unit), for example, an exhaust heat recovery heat exchanger of a fuel cell power generation unit that generates power can be used. The hot water storage and hot water supply system 1 constitutes a fuel cell cogeneration system by being combined with a fuel cell power generation unit, but detailed description of the configuration other than the tank unit 3 is omitted.

  The tank unit 3 includes a hot water storage tank 4, an auxiliary heat source machine 5, a bath heat utilization heat exchanger 6, a heating heat utilization heat exchanger 7, a water supply system passage 8, a hot water supply system passage 9, a pouring passage 11 for supplying hot water to the bath, and a bathtub Bath bath circuit 12 for chasing 10 bath water, Hot water heating circuit 13 for circulating heating water supplied to hot water heating terminals such as floor heating panels and bathroom dryers, Bath water and hot water for bath chasing circuit 12 A heat utilization circulation circuit 14 for heating the heating water of the heating circuit 13, an exhaust heat recovery circulation circuit 15, and the like are provided, and most of them are integrally stored in the exterior case 16.

Next, the hot water storage tank 4 will be described.
The hot water storage tank 4 is composed of a sealed tank capable of storing high-temperature hot water (for example, 65 to 90 ° C.) heated by the external heat source unit 2, and the tank periphery is made of a heat insulating material to prevent heat dissipation of the stored hot water. Covered. A plurality of hot water temperature detection sensors 4 a to 4 d are provided in order at equal intervals from the lower side to the upper side on the outer peripheral portion of the hot water storage tank 4, and a plurality of hot water temperature detection sensors 4 a to 4 d are provided in the hot water storage tank 4. The hot water temperature of the reservoir is detected.

Next, the auxiliary heat source unit 5 will be described.
The auxiliary heat source unit 5 is composed of a known gas water heater that incorporates a burner, a heat exchanger, and the like. The auxiliary heat source machine 5 is heated only when a command is transmitted from the control unit 45 and is combusted only in a special case such as when the hot water temperature in the hot water storage tank 4 is lowered.

Next, the bath heat utilization heat exchanger 6 and the heating heat utilization heat exchanger 7 will be described.
The bath heat utilization heat exchanger 6 heats the bathtub water flowing through the bath remedy circuit 12, and the primary side heat exchange passage portion 6 a that is a part of the heat utilization circulation circuit 14 and the bath remedy circuit 12. It has the secondary side heat exchange passage part 6b which becomes a part. In the bath heat utilization heat exchanger 6, heat is exchanged between the hot water flowing through the heat utilization circulation circuit 14 and the bath water flowing through the bath memorial circuit 12, and the bath water is heated.

  The heating heat utilization heat exchanger 7 heats the heating water flowing through the hot water heating circuit 13, and forms a part of the primary side heat exchange passage portion 7 a and the hot water heating circuit 13 that are part of the heat utilization circulation circuit 14. The secondary side heat exchange passage portion 7b is formed. In the heating heat utilization heat exchanger 7, heat is exchanged between the hot water flowing through the heat utilization circulation circuit 14 and the heating water flowing through the hot water heating circuit 13, and the heating water is heated.

Next, the water supply system passage 8 will be described.
The water supply system passage 8 supplies low temperature clean water from a water supply source to the hot water storage tank 4 and the like, and has an upstream water supply passage portion 8a, an intermediate water supply passage portion 8b, and a downstream water supply passage portion 8c, and the upstream end is at the upper end. Connected to the water source, the downstream end is connected to the lower part of the hot water storage tank 4. A pressure reducing valve 8d is installed in the upstream water supply passage 8a, and a check valve 8e is installed in the intermediate water supply passage 8b.

  A bypass passage portion 17 connected to the hot water supply passage 9 is branched from between the upstream water supply passage portion 8a and the intermediate water supply passage portion 8b. A check valve 17 a is installed in the bypass passage portion 17. A bypass passage 18 connected to the heat utilization circulation circuit 14 is branched from between the intermediate water supply passage 8b and the downstream water supply passage 8c. By this bypass passage 18, low temperature clean water can be supplied to the heat utilization circuit 14, and conversely, hot water can be returned from the heat utilization circuit 14 to the hot water storage tank 4.

Next, the hot water supply system passage 9 will be described.
The hot water supply passage 9 supplies hot water stored in the hot water storage tank 4 to a desired hot water supply destination such as a bath, and is connected to the hot water supply passage 21 connected to the hot water tap and the hot water supply passage 21 from the upper part of the hot water storage tank 4. A tank hot water passage 22, an auxiliary heating passage 23 branched from the tank hot water passage 22 and connected to the combustion type auxiliary heat source device 5, an auxiliary heat source machine hot water passage 24 connected from the auxiliary heat source device 5 to the hot water supply passage 21, etc. have.

  The hot water supply passage 21 includes an upstream hot water supply passage portion 21a through which high-temperature hot water flows, an intermediate hot water supply passage portion 21b through which mixed hot water flows, and a downstream hot water supply passage portion 21c. The upstream end is connected to the tank hot water supply passage 22 and the downstream end is hot water supply. Connected to the stopper.

  A mixing valve 25 is installed between the upstream hot water supply passage portion 21a and the intermediate hot water supply passage portion 21b. A bypass passage portion 17 branched from the water supply passage 8 is connected to the mixing valve 25. The mixing valve 25 controls the mixing ratio of low temperature tap water and high temperature hot water so that the tapping temperature becomes the command temperature. A flow rate sensor 21d and a tapping water proportional valve 26 are installed in the intermediate hot water supply passage 21b. A branch passage portion 27 branched from the bypass passage portion 17 is connected to the intermediate hot water supply passage portion 21b, and a high temperature hot water avoidance electromagnetic valve 28 is installed in the branch passage portion 27.

  The tank hot water passage 22 has an upper effluent hot water passage portion 22 a and a lower effluent hot water passage portion 22 b, an upstream end connected to the upper portion of the hot water storage tank 4, and a downstream end connected to the hot water supply passage 21. An auxiliary heating passage 23 is branched from between the upper effluent passage portion 22a and the lower effluent passage portion 22b.

  The auxiliary heating passage 23 has an upstream heating passage portion 23 a and a downstream heating passage portion 23 b, the upstream end is connected to the tank hot water passage 22, and the downstream end is connected to the inlet of the auxiliary heat source unit 5. The upstream heating passage portion 23a is provided with a check valve 23c, and the downstream heating passage portion 23b is provided with a pressure feed pump 29 and a flow rate sensor 23d.

  A three-way valve 31 capable of switching between the tank hot water passage 22 and the auxiliary heating passage 23 is installed between the upstream heating passage portion 23a and the downstream heating passage portion 23b. The three-way valve 31 is also connected with a hot water return side passage portion 14 d of the heat utilization circulation circuit 14. The three-way valve 31 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 14d. Yes, all the passage portions of the upstream heating passage portion 23a, the downstream heating passage portion 23b, and the hot water return side passage portion 14d can be connected.

  The auxiliary heat source machine outlet hot water passage 24 has an upstream auxiliary hot water outlet passage 24 a and a downstream auxiliary hot water outlet passage 24 b, the upstream end is connected to the outlet of the auxiliary heat source machine 5, and the downstream end is connected to the upstream end of the hot water supply passage 21. Has been. A hot water / outward side passage portion 14a of the heat utilization circulation circuit 14 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 32 is provided in the downstream auxiliary hot water passage portion 24b.

Next, the pouring passage 11 will be described.
The hot water supply passage 11 supplies hot water flowing through the hot water supply passage 21 to the bathtub 10 and is branched downstream from the hot water proportional valve 26 and between the intermediate hot water supply passage portion 21b and the downstream hot water supply passage portion 21c. Connected to the middle of the bath memorial circuit 12. The pouring passage 11 is provided with a flow rate sensor 11a, a pouring electromagnetic valve 33, and the like.

Next, the bath memory circuit 12 will be described.
The bath chase circuit 12 is a circuit that circulates the bath water in order to chase the bath water of the bathtub 10, and has a bath return side passage portion 12a and a bath going side passage portion 12b. A bath circulation pump 36 is installed between the bath return side passage portion 12a and the bath going side passage portion 12b. A water flow switch 12c, a secondary heat exchange passage 6b of the bath heat utilization heat exchanger 6 and a hot water temperature detection sensor 12d are installed in the bath going side passage 12b. A bath water level sensor 12e is installed in the bath return side passage portion 12a, and this bath water level sensor 12e sends a detection signal to the control unit 45 when the bath water level of the bath 10 reaches a set level (for example, 150 to 200L). Send.

Next, the hot water heating circuit 13 will be described.
The hot water heating circuit 13 is a circuit that circulates heating water supplied to a hot water heating terminal such as a floor heating panel or a bathroom dryer. The bypass passage portion 13d is provided. The heating return passage 13a is provided with an expansion tank 37 for absorbing the expansion of the heating water due to heating, and a heating circulation pump 38 for circulating the heating water. The secondary heat exchange passage portion 7b of the heating heat utilization heat exchanger 7 is installed in the heating high-temperature going passage portion 13b. A bypass thermal valve 39 is installed in the bypass passage portion 13d.

Next, the heat utilization circulation circuit 14 will be described.
The heat utilization circulation circuit 14 is a closed circuit that circulates hot water and performs heat exchange between the bath chase circuit 12 and the hot water heating circuit 13, and includes a hot water going side passage portion 14a, a heating heat utilization passage portion 14b, a bath It has a heat use passage 14c, a hot water return side passage 14d, a downstream heating passage 23b of the auxiliary heating passage 23, and an upstream auxiliary hot water passage 24a of the auxiliary heat source machine hot water passage 24. A primary heat exchange passage portion 6a of the bath heat utilization heat exchanger 6 and a bath heat utilization opening / closing valve 41 are installed in the bath heat utilization passage portion 14c, and the heating heat utilization heat exchanger 7 is disposed in the heating heat utilization passage portion 14b. Primary side heat exchange passage 7a and heating heat utilization opening / closing valve 42 are installed.

  When hot water is circulated in the heat utilization circulation circuit 14 to exchange heat with bathtub water or heating water, hot water flows into the auxiliary heat source machine 5 from the downstream heating passage portion 23b via the pressure feed pump 29, and the auxiliary heat source machine 5 The hot hot water after being heated by the air flows through the upstream auxiliary hot water passage portion 24a and the hot water going-out passage portion 14a and is sent to the bath heat utilization passage portion 14c and the heating heat utilization passage portion 14b, and the primary side heat exchange. The hot water exchanged between the bath water and the heating water in the passage portions 6a and 7a is returned to the downstream heating passage portion 23b through the hot water return side passage portion 14d.

Next, the exhaust heat recovery circuit 15 will be described.
The exhaust heat recovery / circulation circuit 15 is a closed circuit that circulates hot water between the hot water storage tank 4 and the external heat source unit 2 to recover the exhaust heat of the external heat source unit 2, and includes a low temperature side circulation passage portion 15a and a high temperature side circulation. The upper end is connected to the lower part of the hot water storage tank 4, and the downstream end is connected to the upper part of the hot water storage tank 4.

  A branch passage portion 15c connected to the low temperature side circulation passage portion 15a is branched from the high temperature side circulation passage portion 15b, and a circulation circuit including the hot water storage tank 4 and a circulation circuit bypassing the hot water storage tank 4 are selected in this branch portion. A three-way valve 43 that can be selectively selected is provided. Inside the external heat source device 2, a circulation pump 44 is installed in the low temperature side circulation passage portion 15a, and heat exchange of the external heat source device 2 is performed between the low temperature side circulation passage portion 15a and the high temperature side circulation passage portion 15b. (Not shown) is installed.

Next, the control unit 45 will be described.
As shown in FIGS. 1-3, the hot water storage hot-water supply system 1 is controlled by the control unit 45 (equivalent to a control means). The detection signals of various sensors are transmitted to the control unit 45, and the control unit 45 controls the operation of the hot water storage hot water system 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 filling operation, reheating operation, high temperature hot water supply operation, heating operation, freeze prevention operation, exhaust heat recovery operation, etc.) are performed.

  The control unit 45 can perform data communication with an operation remote controller that can be operated by the user. When various operations are set by operating the operation remote controller, a command signal is transmitted from the operation remote controller to the control unit 45. The For example, when the target hot water set temperature is set by operating the switch of the operation remote controller, the target hot water set temperature data is transmitted from the operation remote controller to the control unit 45.

  When supplying hot water, when the hot water in the hot water storage tank 4 exceeds a first set temperature (for example, 40 ° C.), the control unit 45 mixes the hot water in the hot water storage tank 4 with the low temperature water and sets the first set temperature. When the hot water in the hot water storage tank 4 is lower than the first set temperature and higher than the second set temperature (for example, 30 ° C.), the hot water in the hot water storage tank 4 is mixed with the low temperature water. After adjusting to the second set temperature or lower, reheating with the auxiliary heat source unit 5 to adjust to the first set temperature to supply hot water, and when the hot water in the hot water storage tank 4 falls below the second set temperature, the hot water storage tank The hot water of No. 4 is reheated by the auxiliary heat source unit 5 and adjusted to the first set temperature to supply hot water.

Next, the hot water operation related to the present invention will be described.
When the hot water from the hot water storage tank 4 to the bathtub 10 is filled, if the hot water in the hot water storage tank 4 exceeds the first set temperature, the control unit 45 mixes the hot water in the hot water storage tank 4 with the low temperature water. The hot water filling is performed by adjusting to the first set temperature, and when the hot water in the hot water storage tank 4 is lower than the first set temperature and higher than the second set temperature, the operation of the auxiliary heat source device 5 is prohibited and the hot water is filled. When the hot water in the hot water storage tank 4 is lower than the second set temperature, the hot water in the hot water storage tank 4 is heated by the auxiliary heat source device 5 and the hot water is filled. Adjusts the bath water to the first set temperature by performing reheating.

  That is, the control unit 45 adjusts the hot water in the hot water storage tank 4 to the first set temperature via the auxiliary heat source unit 5, the mixing valve 25, the pouring electromagnetic valve 33, etc., and then performs a normal hot water operation for supplying to the bathtub 10. In addition, when the hot water in the hot water storage tank 4 is, for example, a medium temperature water of about 30 to 40 ° C. lower than the first set temperature, the operation of the auxiliary heat source machine 5 is prohibited and the low temperature clean water is not mixed. A hot water filling operation that uses up the medium-temperature water (see the arrow indicating the flow of hot water in FIG. 1) can be executed.

  Next, when the hot water filling operation is set, the control unit 45 automatically executes the hot water filling that prohibits the operation of the auxiliary heat source unit 5 when the hot water temperature of the hot water storage tank 4 is equal to or lower than the first set temperature. The operation control will be described based on the flowcharts of FIGS. In the figure, the symbol Si (i = 1, 2,...) Indicates each step. The control program for the hot water filling operation control is stored in the control unit 45 in advance.

  When this control is started in the flowcharts of FIGS. 4 and 5, it is first determined in S1 whether or not the hot water filling operation is started. When the conditions for starting the hot water filling operation (command from the operation remote controller, timer setting, etc.) are established, that is, when the determination of S1 is Yes, the process proceeds to S2, and the determination of S1 is No. Repeat S1.

  Next, in S2, the detection signal of the uppermost hot water temperature detection sensor 4d among the plurality of hot water temperature detection sensors 4a to 4d installed in the hot water storage tank 4 is read, and based on this detection signal, the inside of the hot water storage tank 4 is read. The upper hot water temperature Ta of the reservoir in the upper part (near the place where the hot water temperature detection sensor 4d is installed) is calculated, and the process proceeds to S3.

  Next, in S3, it is determined whether or not the upper hot water temperature Ta in the hot water storage tank 4 is equal to or lower than a first set temperature T1 (for example, 40 ° C.) that is a hot water supply set temperature. When the temperature is lower than the first set temperature T1 (when hot water is stored in the hot water storage tank 4), that is, when the determination of S3 is Yes, the process proceeds to S4, and the upper hot water temperature Ta in the hot water storage tank 4 is the first. When the temperature is higher than the set temperature T1 (when hot water is stored in the hot water storage tank 4), that is, when the determination in S3 is No, the process proceeds to S5, and the hot water in the hot water storage tank 4 is cooled through the mixing valve 25. A normal hot water filling operation in which hot water adjusted to the first set temperature T1 is supplied to the bathtub 10 is mixed and adjusted with the clean water.

  Next, in S4, it is determined whether or not the upper hot water temperature Ta in the hot water storage tank 4 is equal to or higher than a second set temperature T2 (for example, 30 ° C.), and the upper hot water temperature Ta in the hot water storage tank 4 is set to the second set temperature T2. In the above case, that is, when the determination of S4 is Yes, the process proceeds to S6, and when the upper hot water temperature Ta in the hot water storage tank 4 is lower than the second set temperature T2 (too much heating even with the minimum combustion amount of the auxiliary heat source unit 5). If the determination in S4 is No, the process proceeds to S7, where the hot water in the hot water storage tank 4 is heated by the auxiliary heat source unit 5 and the hot water adjusted to the first set temperature T1 is obtained. A normal hot water operation for supplying hot water to the bathtub 10 is performed.

  Next, in S6, the hot water storage hot water supply system 1 prohibits the operation of the auxiliary heat source unit 5 and starts the hot water filling operation (see the arrow indicating the flow of hot water in FIG. 1). That is, the control unit 45 controls various devices (mixing valve 25, pouring electromagnetic valve 33, etc.) of the hot water storage hot water system 1 so that the temperature of hot water (medium temperature water) is not adjusted from the upper part of the hot water storage tank 4. 10 is switched to the hot water filling operation state to be supplied to No. 10, and the process proceeds to S8.

  Next, in S8, the detection signal of the bath water level sensor 12e is read during the filling operation, and in S9, it is determined whether or not the bathtub water level of the bathtub 10 has reached the set level, and the bathtub water level has reached the set level. In other words, if the determination in S9 is Yes, the process proceeds to S10, the hot water filling operation is terminated, and the process proceeds to S20. When the bathtub water level has not reached the set level, that is, when the determination in S9 is No, the process proceeds to S11.

  Next, in S11, a detection signal of the uppermost hot water temperature detection sensor 4d among the plurality of hot water temperature detection sensors 4a to 4d is read, and an upper part (hot water temperature detection sensor in the hot water tank 4) is read based on this detection signal. The upper hot water temperature Ta of the reservoir in the vicinity of 4d is calculated, and the process proceeds to S12.

  Next, in S12, it is determined whether or not the upper hot water temperature Ta in the hot water storage tank 4 is lower than a second set temperature T2 (for example, 30 ° C.), and the intermediate temperature water (for example, 30 ° C. to 40 ° C.) of the hot water storage tank 4 is determined. When the upper hot water temperature Ta in the hot water storage tank 4 becomes lower than the second set temperature T2, that is, when the determination in S12 is Yes, the process proceeds to S13, the hot water filling operation is terminated, and the process proceeds to S14. . If the upper hot water temperature Ta in the hot water storage tank 4 is higher than the second set temperature T2 and the medium hot water remains in the hot water storage tank 4, that is, if the determination in S12 is No, the process returns to S8 and repeats S8 to S12. Run.

  Next, in S14, the hot water storage hot water supply system 1 cancels the operation prohibition of the auxiliary heat source unit 5 and starts a hot water filling operation by heating the auxiliary heat source unit 5 (see the arrow indicating the flow of hot water in FIG. 2). That is, when the hot water filling operation is terminated when the upper hot water temperature Ta in the hot water storage tank 4 is lower than the second set temperature T2, the medium hot water is used up, the bathtub water level is low, and the bathtub water temperature is low. The control unit 45 controls various devices of the hot water storage hot water supply system 1 (auxiliary heat source machine 5, mixing valve 25, pouring electromagnetic valve 33, etc.), so that the hot water storage hot water supply system 1 is filled with water by heating the auxiliary heat source machine 5. Switch to the state and proceed to S15. In addition, the hot water temperature poured into the bathtub 10 at the time of filling by heating of the auxiliary heat source unit 5 may be adjusted to the first set temperature T1, or the bathtub water level and the bathtub poured during the filling operation of S6 to S13. By calculating the water temperature, the amount of hot water to be poured and the hot water temperature during hot water filling operation by heating of the auxiliary heat source unit 5 may be determined.

  Next, in S15, the detection signal of the bath water level sensor 12e is read during the filling operation, and in S16, it is determined whether or not the bathtub water level of the bathtub 10 has reached the set level, and the bathtub water level has reached the set level. If it is determined, that is, if the determination in S16 is Yes, the process proceeds to S17, the hot water filling operation by heating of the auxiliary heat source unit 5 is terminated, and the process proceeds to S18. When the bathtub water level has not reached the set level, that is, when the determination in S16 is No, the process returns to S15, and S15 and S16 are repeatedly executed. In S17, the series of controls may be terminated when the hot water filling operation by heating of the auxiliary heat source unit 5 is completed.

  Next, in S18, the detection signal of the hot water temperature detection sensor 12d installed in the bath going-side passage portion 12b of the bath chase circuit 12 is read, and the bathtub water temperature Tb stored in the bathtub 10 is read based on this detection signal. And the process proceeds to S19. When the detection signal is read by the hot / cold water temperature detection sensor 12d, the bath circulation pump 36 may be driven to read the detection signal in a state where the bath water is circulated through the bath chase circuit 12.

  Next, in S19, it is determined whether or not the bathtub water temperature Tb of the bathtub 10 is lower than the first set temperature T1, and if the bathtub water temperature Tb of the bathtub 10 is lower than the first set temperature T1 (high temperature hot water supply) If the bath water temperature does not reach the first set temperature even after operation), that is, if the determination in S19 is Yes, the process proceeds to S20, and the chasing operation (see the arrow indicating the flow of hot water in FIG. 3) is performed. Start and go to S21. When the bathtub water temperature Tb of the bathtub 10 is equal to or higher than the first set temperature T1, that is, when the determination in S19 is No, the bathtub water level has reached the set level, and the bathtub water temperature has reached the first set temperature T1, This series of control ends.

  Next, in S21, the detection signal of the hot water temperature detection sensor 12d is read during the chasing operation, and the bathtub water temperature Tb of the bathtub 10 is calculated from the bathtub water circulating through the bath-side passage portion 12b based on this detection signal. Then, the process proceeds to S22.

  Next, in S22, it is determined whether or not the bathtub water temperature Tb of the bathtub 10 is equal to or higher than the first set temperature T1, and when the bathtub water temperature Tb of the bathtub 10 is equal to or higher than the first set temperature T1, that is, the determination of S22. If Yes, the process proceeds to S23, the chasing operation is terminated, the bath water level has reached the set level, and the bath water temperature has reached the first set temperature T1, so this series of controls is terminated. If the determination in S22 is No, the process returns to S21, and S21 and S22 are repeatedly executed.

Next, the operation and effect of the hot water storage hot water system 1 of the present invention will be described.
When the hot water supply of the hot water storage tank 4 to the bathtub 10 is performed, the control unit 45 provided in the hot water storage hot water supply system 1 has the hot water of the hot water storage tank 4 not higher than the first set temperature and not lower than the second set temperature. In some cases, that is, when warm water is stored in the upper part of the hot water storage tank 4, the auxiliary heat source machine 5 is prohibited from being operated and hot water filling is performed. The hot water that is present and is equal to or higher than the second set temperature is directly used for hot water filling without adjusting the temperature.

  Therefore, when hot water is filled, hot water that is not more than the first set temperature and not less than the second set temperature stored in the hot water storage tank 4 can be actively consumed, so that the hot water temperature in the hot water storage tank 4 is efficiently increased. The efficiency of exhaust heat recovery of the external heat source device 2 is improved. When the external heat source unit 2 is a fuel cell, the amount of condensed water generated increases, and the operating efficiency of the fuel cell cogeneration system is improved.

  In addition, since hot water that is lower than or equal to the first set temperature of the hot water storage tank 4 and higher than or equal to the second set temperature is actively consumed, the hot water in the hot water storage tank 4 is heated by the auxiliary heat source unit 5 to fill the hot water. Hot water filling similar to normal hot water operation is possible.

Next, a mode in which the above embodiment is partially changed will be described.
[1] In the above embodiment, S11 to S19 in the flowchart of the hot water operation control may be omitted. That is, by omitting the step of determining whether or not the hot water in the hot water storage tank 4 has become equal to or lower than the second set temperature, hot water having a temperature not higher than the first set temperature in the hot water storage tank 4 is reduced to the set level in the bathtub 10. By supplying until it reaches, hot water below the first set temperature of the hot water storage tank 4 can be actively consumed. After the bath water level has reached the set level, the hot water filling is performed by adjusting the bath water to the set temperature in the same manner as in the embodiment.

[2] In the above embodiment, the first and second set temperatures are merely examples, and these temperatures can be changed as appropriate. For example, as the second set temperature, the first set temperature minus the set value You may apply the temperature of (alpha) (for example, 10 degreeC).

[3] In addition, those skilled in the art can implement the present invention in various forms with 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 system 2 External heat source machine 4 Hot water storage tank 5 Auxiliary heat source machine 10 Bath 11 Pouring passage 12 Bath chase circuit 15 Waste heat recovery circulation circuit 45 Control unit

Claims (1)

A heat source machine, a hot water storage tank, an exhaust heat recovery circuit that recovers exhaust heat of the heat source machine using hot water of the hot water storage tank, an auxiliary heat source machine that reheats hot water of the hot water storage tank, and the hot water storage tank A hot water storage and hot water supply system comprising a pouring passage for supplying hot water to the bathtub and a bath memory circuit for tracking the bathtub water of the bathtub. When hot water is supplied, the hot water in the hot water storage tank is first. When the set temperature is exceeded, hot water in the hot water storage tank is mixed with low temperature water to adjust the first set temperature to supply hot water, and the hot water in the hot water storage tank is equal to or lower than the first set temperature and When the temperature is equal to or higher than the second set temperature, the hot water in the hot water storage tank is mixed with low-temperature water and adjusted to the second set temperature or lower, and then reheated by the auxiliary heat source device to be adjusted to the first set temperature. Hot water is supplied to the hot water storage tank. If it falls below the set temperature, in the hot water storage hot water system that the hot water of the hot water storage tank and re-heated in the auxiliary heat source machine performs a hot water supply is adjusted to the first predetermined temperature,
When hot water is filled from the hot water storage tank to the bathtub, if the hot water in the hot water storage tank exceeds the first set temperature, the hot water in the hot water storage tank is mixed with low-temperature water to make the first setting. When the temperature of the hot water storage tank is lower than the first set temperature and higher than the second set temperature, the auxiliary heat source machine is prohibited from operating and the hot water is charged. A hot water storage and hot water supply system comprising control means for heating the hot water in the hot water storage tank with the auxiliary heat source device when the hot water in the hot water storage tank falls below the second set temperature. .