JP5838914B2 - Hot water storage water heater - Google Patents

Description

  The present invention relates to a hot water storage type water heater.

  Conventionally, bath heat recovery of this type of water heater is to perform heat exchange between the waste heat of the bathtub water and the water flowing through the water supply pipe with a heat recovery device provided in the bypass pipe branched from the water supply pipe at the time of hot water supply. Therefore, it has been proposed to recover the heat in the bathtub and use it for preheating water supply (Patent Document 1).

JP2011-12845A

  However, in order to perform heat exchange with high efficiency, the heat recovery unit often has a complicated shape for increasing the heat transfer area, and the flow resistance generally increases. is there. Therefore, in the configuration of Patent Document 1 described above, from the water supply pipe to the hot water supply pipe via the hot water storage tank, and from the bypass pipe branched to the water supply pipe to the hot water supply pipe via the heat recovery device. The flow resistance ratio of the flow path via the heat recovery device is very high, and the flow rate of hot water flowing through the flow path via the hot water storage tank is higher than the flow rate of hot water flowing via the heat recovery device. There is a problem that the flow rate required for exchanging heat in the heat recovery device becomes very large, and the waste heat recovery efficiency of the bathtub water is thereby reduced.

  Therefore, it is necessary to add a flow rate adjusting mechanism such as a mixing valve for controlling the pipe flow rate ratio at the junction of the hot water supply pipe and the bypass pipe, resulting in a problem that the number of parts increases and the product cost increases. . Assuming that the user uses hot water at the faucet or shower hot water, the time required for one hot water supply is generally in the order of several tens of seconds to several minutes. In order to achieve this, it is necessary to quickly and efficiently recover bath heat after detecting hot water supply. For this reason, in the conventional technique, it is difficult to secure the required flow rate of the bypass circuit, and it is difficult to improve the bath heat recovery capability.

  Furthermore, in the case of the configuration in which the heat recovery unit is provided in the bypass pipe branched from the water supply pipe, the flow rate flowing out from the downstream hot water supply terminal is reduced because the flow resistance through the heat recovery apparatus increases as described above. Therefore, there is also a problem that it becomes impossible to discharge the required flow rate desired by the user. In addition, the provision of a heat recovery device in the bypass pipe simply adds the number of parts as a product, which increases the product cost and is a major issue for providing high-efficiency water heaters at low cost to consumers. It was.

  The present invention has been made to solve the above-described problems, and in order to satisfy basic functions such as boiling, reheating, and hot water, which are functions of a hot water storage hot water heater using a heat pump or the like. An object of the present invention is to provide a hot water storage type hot water heater capable of recovering waste heat of bathtub water with high efficiency by utilizing an existing component configuration to be used.

The hot water storage type hot water supply apparatus according to the present invention includes a hot water storage tank for storing hot water, a heating heat exchanger for heating the water in the hot water storage tank to high temperature water using a predetermined heating means, and a hot water storage tank. A heat exchanger that exchanges heat between the hot water in the bathtub and the bathtub water in the bathtub, one end is connected to the lower part of the hot water storage tank, a heat exchanger for boiling is installed in the middle, and the other end is the upper part of the hot water tank The boiling water circulation circuit connected to the top, one end connected to the upper part of the hot water storage tank, the use side heat exchanger is installed in the middle, the other end is the lower part of the hot water tank in the boiling water circulation circuit and the heat exchanger for boiling A heat source side pipe connected between the first flow path switching means installed at the connecting portion between the boiling water circulating circuit and the other end of the heat source side pipe, and a circuit configured annularly from the bathtub On the way, the use side heat exchanger and bath circulation pump are installed. Boiling the bath water circulation circuit, and the installed circulation pump between the first flow path switching unit and the boiling heat exchanger in water heating water circulation circuit, the discharge side of the circulation pump in the circulation circuit boiling one end A bypass pipe connected between the boiling heat exchanger in the raised water circulation circuit and the other end connected between the boiling heat exchanger in the boiling water circulation circuit and the upper part of the hot water storage tank, and the raised water circulation Second flow path switching means installed at the connection between the circuit and the other end of the bypass pipe, one end is connected to the lower part of the hot water storage tank, and the other end is the upper part of the use side heat exchanger and the hot water storage tank in the heat source side pipe A low-temperature water pipe connected between the other end of the low-temperature water pipe, a third flow path switching means installed at the connection between the other end of the low-temperature water pipe and the heat source side pipe; Second channel switching hand , The other end of the hot water supply pipe connected to the hot water supply terminal, the low temperature water detection means for detecting the temperature of the low temperature water flowing from the hot water storage tank to the low temperature water pipe, and the outflow from the bathtub to the bathtub water circulation circuit A bath water temperature detecting means for detecting the temperature of the bath water to be performed, and a flow rate detecting means provided in the middle of the hot water supply pipe, operating the first, second and third flow path switching means, The flow rate in a state in which a flow path communicating with the hot water supply pipe is formed through the third flow path switching means, the use side heat exchanger, the first flow path switching means, the circulation pump and the second flow path switching means in this order from the lower part It drives the bath circulation pump when the detection means detects the flow rate of more than a predetermined flow rate, and a control means for detecting temperature by low-temperature water detecting means drives the circulation pump is lower than the temperature detected by the bath water temperature detection means , With .

  According to the present invention, the existing component configuration used for satisfying basic functions such as boiling, reheating, and hot water supply, which are functions of a hot water storage water heater using a heat pump or the like, is used, and bath water Therefore, it is possible to provide a hot water storage type hot water heater that can efficiently recover waste heat.

It is a block diagram of the hot water storage type water heater in Embodiment 1 of this invention. It is a circuit block diagram in the standby state of the hot water storage type water heater in Embodiment 1 of this invention. It is a circuit block diagram at the time of the boiling independent operation | movement of the hot water storage type water heater in Embodiment 1 of this invention. It is a circuit block diagram of the bathtub water pursuit operation of the hot water storage type water heater in Embodiment 1 of this invention. It is a circuit block diagram at the time of the bath water waste heat recovery driving | operation standby at the time of the hot water supply of the hot water storage type water heater in Embodiment 1 of this invention. It is a circuit block diagram at the time of the bathtub water waste heat recovery driving | operation at the time of the hot_water | molten_metal supply of the hot water storage type water heater in Embodiment 1 of this invention. It is a circuit block diagram at the time of standby operation of the hot water storage type hot water heater in Embodiment 1 of this invention. It is a block diagram of the hot water storage type water heater in Embodiment 2 of this invention. It is a circuit block diagram at the time of the simultaneous operation | movement of the bathtub water waste heat recovery operation | movement of the hot water storage type water heater in Embodiment 2 of this invention, and the freeze prevention operation | movement of heat pump piping.

  Embodiments of the present invention will be described below with reference to the drawings. In addition, the same code | symbol is attached | subjected to the element which is common in each figure, and the overlapping description is abbreviate | omitted.

Embodiment 1 FIG.
FIG. 1 is a configuration diagram of a hot water storage type water heater 100 according to Embodiment 1 of the present invention. A hot water storage type water heater 100 shown in FIG. 1 includes a hot water storage tank unit 1 and a heat pump unit 60 configured to use a heat pump cycle. The two units 1 and 60 are connected by a heat pump inlet pipe 41 and a heat pump outlet pipe 42. The hot water storage tank unit 1 has a control unit 70 built therein. Operations of various valves, pumps and the like provided in the hot water storage tank unit 1 and the heat pump unit 60 are controlled by a control unit 70 electrically connected thereto. Hereinafter, each component of the hot water storage type water heater 100 will be described.

  The heat pump unit 60 functions as a heating means for heating (boiling) the low temperature water led from the hot water storage tank unit 1. The heat pump unit 60 includes a compressor 61, a heating heat exchanger 62, an expansion valve 63, and an air heat exchanger 64 connected in a ring shape with a refrigerant circulation pipe 65 to constitute a refrigeration cycle (heat pump cycle). The boiling heat exchanger 62 is for exchanging heat between the refrigerant flowing through the refrigerant circulation pipe 65 constituting the heat pump cycle and the low-temperature water led from the hot water storage tank unit 1.

  The HP outlet side thermistor 66 is a temperature sensor for detecting the temperature of the high-temperature water heated by the boiling heat exchanger 62, and is provided in the heat pump outlet pipe 42. The outside air temperature thermistor 67 is a temperature sensor for detecting the outside air temperature around the heat pump unit 60, and is provided at a part exposed to the outside air. In order to obtain high-temperature water with the heat pump unit 60, the heat pump cycle is preferably operated at a pressure exceeding the critical pressure using carbon dioxide as the refrigerant. However, the heat pump cycle applicable in the present invention is not limited to the supercritical heat pump cycle, and may be a heat pump cycle of a general critical pressure or lower. In this case, chlorofluorocarbon, ammonia, or the like may be used as the refrigerant.

  On the other hand, the hot water storage tank unit 1 incorporates the following various parts and piping. The hot water storage tank 10 is for storing hot water. A water supply pipe 2 for supplying city water is connected to the lower part of the hot water storage tank 10, and a hot water supply pipe 3 for supplying the stored hot water to the outside of the water heater is connected to the upper part of the hot water storage tank 10. The pipe 43 is branched and connected.

  In addition, the hot water heated by the heat pump unit 60 flows into the hot water storage tank 10 from the upper part of the tank, and the low temperature water flows out from the lower part of the tank through the tank lower pipe 40, thereby Hot water is stored so that there is a temperature difference between the bottom and the bottom.

  Further, the hot water storage tank 10 is provided with remaining hot water thermistors 11 and 12 for detecting the temperature distribution of the hot water in the hot water storage tank 10 by changing the mounting height. Based on the temperature distribution acquired by the remaining hot water thermistors 11 and 12, the amount of hot water in the hot water storage tank 10 is grasped, and the start and stop of the hot water boiling operation in the hot water storage tank 10 by the heat pump unit 60 is controlled. Is done.

  The hot water storage tank unit 1 includes a circulation pump 21 and a use side heat exchanger 22. The circulation pump 21 is a pump for circulating hot water through various pipes to be described later in the hot water storage tank unit 1, and is provided in the middle of the heat pump inlet pipe 41. The use-side heat exchanger 22 uses the high-temperature water supplied from the hot water storage tank 10 and the heat pump unit 60 to heat the secondary-side heating target water (tub circulation water, heating circulation water, etc.). It is an exchanger.

  In the present embodiment, as a secondary side configuration of the use side heat exchanger 22, a bathtub water circulation circuit 51 that circulates hot water in the bathtub 50 will be described as an example. The use side heat exchanger 22 is installed in the middle of the bathtub water circulation circuit 51. Further, in the middle of the bathtub water circulation circuit 51, a secondary-side circulation pump 52 for circulating the bathtub water and a bathtub inlet-side thermistor 53 for detecting the temperature of the bathtub water discharged from the bathtub 50 are installed. Yes.

  Next, the valves and piping included in the hot water storage tank unit 1 will be described. The hot water storage tank unit 1 has a three-way valve 31, a four-way valve 32, and a three-way valve 33. The three-way valve 31 is a flow path switching means having two inlets (a port and b port) through which hot water flows and one outlet (c port) through which hot water flows out. Either the a port or the b port The hot water path can be switched so that hot water flows in from the water.

  The four-way valve 32 is a flow path switching means having two inlets (b port and c port) through which hot water flows in and two outlets (a port and d port) through which hot water flows out. , A-b route, a-c route, cd route, and b-d route are configured to be switchable.

  The three-way valve 33 is a flow path switching means having two inlets (a port and b port) through which hot water flows in and one outlet (c port) through which hot water flows out, from either the a port or the b port. The hot water path can be switched so that the hot water flows in.

  The hot water storage tank unit 1 includes a tank lower pipe 40, the heat pump inlet pipe 41, the heat pump outlet pipe 42 and the tank upper pipe 43, a heating circulation circuit, a tank return pipe 44, and a use side heat exchanger primary. A side inlet pipe 45, a use side heat exchanger primary side outlet pipe 46, a bypass pipe 47, a high temperature water pipe 48 and a low temperature water pipe 49 are provided.

  More specifically, the tank lower pipe 40 is a flow path that connects the first lower part of the hot water storage tank 10 and the a port of the three-way valve 31. The heat pump inlet pipe 41 is a flow path that connects the c port of the three-way valve 31 and the inlet side of the heat pump unit 60, and the heat pump outlet pipe 42 connects the outlet side of the heat pump unit 60 and the c port of the four-way valve 32. This is a flow path.

  The tank upper pipe 43 is a flow path that connects the d port of the four-way valve 32 and the upper part of the hot water storage tank 10, and the tank return pipe 44 is between the a port of the four-way valve 32 and the central part of the hot water storage tank 10 from the lower part. It is a flow path connecting the provided return port (second lower part).

  The high temperature water pipe 48 is a flow path connecting the upper part of the hot water storage tank 10 and the a port of the three-way valve 33, and the use side heat exchanger primary side inlet pipe 45 is used with the c port of the three way valve 33. It is a flow path connecting the primary side inlet of the side heat exchanger 22, and the usage side heat exchanger primary side outlet pipe 46 is a primary port of the usage side heat exchanger 22 and a b port of the three-way valve 31. The low temperature water pipe 49 is a flow path that connects the lower part of the hot water storage tank 10 and the b port of the three-way valve 33. Further, the bypass pipe 47 is a flow path branched from the discharge side of the circulation pump 21 in the heat pump inlet pipe 41 and connected to the b port of the four-way valve 32. Further, a check valve 55 is provided in the middle of the low-temperature water pipe 49 to prevent the backflow of hot water from the b port of the three-way valve 33 to the lower part of the hot water storage tank 10.

  The hot water storage tank unit 1 further includes a water supply pipe 2, a hot water supply pipe 3, a water supply branch pipe 4, a hot water supply mixing valve 6, and a mixed water hot water supply pipe 5. More specifically, the water supply branch pipe 4 is branched from the middle of the water supply pipe 2 to constitute a water side pipe of the hot water supply mixing valve 6. The hot water supply pipe 3 branches from the tank upper pipe 43 and constitutes a hot water side pipe of the hot water supply mixing valve 6. In addition, since the supply pressure from city water changes with areas, the pressure reducing valve 7 for hold | maintaining the pressure applied to a hot water storage tank below a fixed value is connected in the middle of the water supply piping 2. FIG.

  The hot water mixing valve 6 adjusts the flow rate ratio of the high temperature water supplied from the hot water supply pipe 3 and the water flowing from the water supply branch pipe 4 to the set temperature set by a remote controller (not shown) that can be set by the user. It is a valve to do. The hot water whose temperature has been adjusted by the hot water supply mixing valve 6 is supplied from the mixed water hot water supply pipe 5 to a faucet 80 such as a shower or currant used by the user.

  A hot water supply thermistor 13 is provided in the middle of the hot water supply pipe 3. Further, the mixed water hot water pipe 5 is provided with a mixed water thermistor 9 and a mixed water flow rate sensor 8, and the mixed water is set by performing feedback control on the mixing valve 6 based on the temperature of the mixed water thermistor 9. Controlled by temperature. Further, the presence / absence of hot water supply is determined based on the detection value of the mixed water flow rate sensor 8. In this case, temperature control is performed based on the detection value of the mixed water thermistor 9.

  In the hot water storage type water heater 100 of the present embodiment, the three-way valve 31 is controlled according to the operation state shown in FIGS. 2 to 6 below, and between the following first and second flow path configurations, The hot water flow path in the hot water storage tank unit 1 is switched and used.

  More specifically, the “first flow path configuration” that can be selected by the three-way valve 31 means that the first lower part of the hot water storage tank 10 and the heating heat exchanger 62 connect the tank lower pipe 40 and the heat pump inlet pipe 41. The “second flow path configuration” means that the use side heat exchanger primary side outlet pipe 46 and the heating heat exchanger 62 are connected via the heat pump inlet pipe 41. It is a flow path form that communicates.

  Moreover, in the hot water storage type hot water heater 100 of the present embodiment, the four-way valve 32 is controlled according to the operation state shown in FIGS. Thus, the hot water flow path in the hot water storage tank unit 1 is switched and used.

  More specifically, the “first flow path configuration” that can be selected by the four-way valve 32 means that the heating heat exchanger 62 and the upper part of the hot water storage tank 10 are connected via the heat pump outlet pipe 42 and the tank upper pipe 43. The “second flow path configuration” is a flow channel configuration in which the boiling heat exchanger 62 and the tank return pipe 44 communicate with each other via the heat pump outlet pipe 42. The “third flow path configuration” is a flow channel configuration in which the bypass pipe 47 and the lower part of the hot water storage tank 10 communicate with each other via the tank return pipe 44. Further, the “fourth flow path configuration” is a flow path configuration in which the bypass pipe 47 and the upper part of the hot water storage tank 10 communicate with each other via the tank upper pipe 43.

  Furthermore, in the hot water storage type hot water heater 100 of the present embodiment, the three-way valve 33 is controlled according to the operation state shown in FIGS. 2 to 6 below, and between the following first and second flow path configurations. Thus, the hot water flow path in the hot water storage tank unit 1 is switched and used.

  More specifically, the “first flow path configuration” that can be selected by the three-way valve 33 is that the upper part of the hot water storage tank 10 and the use side heat exchanger 22 are connected to the high temperature water pipe 48 and the use side heat exchanger primary side inlet. It is a flow path form communicating through the pipe 45, and the “second flow path form” means that the lower part of the hot water storage tank 10 and the use side heat exchanger 22 are connected to the low temperature water pipe 49 and the use side heat exchanger primary. It is a flow path form communicating through the side inlet pipe 45.

  FIG. 2 is a circuit configuration diagram in the standby state of hot water storage type water heater 100 according to Embodiment 1 of the present invention. In addition, this standby state is a state in which any operation such as a heating operation and bath water replenishment operation described later is not performed.

  In the standby state, the three-way valve 31 is controlled so that the a port communicates with the c port and the b port is closed (that is, the first flow path configuration of the three-way valve 31 is selected). The Accordingly, the tank lower pipe 40 and the heat pump inlet pipe 41 communicate with each other, and the flow path from the usage side heat exchanger 22 is blocked by closing the usage side heat exchanger primary side outlet pipe 46 side.

  In the standby state, the four-way valve 32 is selected such that the port a and the port c communicate with each other and the port b and the port d are closed (that is, the second flow path configuration of the four-way valve 32 is selected). Controlled). Thereby, the heat pump outlet pipe 42 and the tank return pipe 44 communicate with each other, and the flow path on the tank upper pipe 43 side is closed. In this standby state, all of the circulation pump 21, the heat pump unit 60, and the secondary side circulation pump 52 are in a stopped state.

  Further, the three-way valve 33 is controlled so that the b port and the c port communicate with each other and the a port is closed (that is, the second flow path configuration of the three-way valve 33 is selected). As a result, the low temperature water pipe 49 and the use side heat exchanger primary side inlet pipe 45 communicate with each other, and the high temperature water pipe 48 side is closed and the flow path from the upper part of the hot water storage tank 10 is blocked.

  Next, FIG. 3 is a circuit configuration diagram of the hot water storage type water heater 100 according to Embodiment 1 of the present invention at the time of a single heating operation. In addition, the boiling-up single operation here is a thing in which the boiling-up operation which uses the heat pump unit 60 to boil the water in the hot water storage tank 10 is performed independently.

  During this boiling-only operation, the three-way valve 31 communicates with the a-port and the c-port, and the b-port is closed (that is, the first flow path configuration of the three-way valve 31 is selected. Controlled). Accordingly, the tank lower pipe 40 and the heat pump inlet pipe 41 communicate with each other, and the flow path from the usage side heat exchanger 22 is blocked by closing the usage side heat exchanger primary side outlet pipe 46 side.

  Further, during the boiling-only operation, the four-way valve 32 is configured such that the c port and the d port communicate with each other and the a port and the b port are closed (that is, the first flow path configuration of the four-way valve 32 is To be controlled).

  Thereby, the heat pump outlet pipe 42 and the tank upper pipe 43 communicate with each other, and the flow path to the second lower part of the hot water storage tank 10 is blocked by closing the tank return pipe 44 side. Here, since the position of the valve of the three-way valve 33 does not directly affect the boiling, detailed description is omitted.

  The boiling-up single operation is executed by starting the operation of the circulation pump 21 and the heat pump unit 60 in a state where the three-way valve 31 and the four-way valve 32 are controlled as described above. As a result, the low-temperature water flowing out from the first lower part of the hot water storage tank 10 is guided to the heat pump unit 60 via the tank lower pipe 40, the three-way valve 31, the circulation pump 21 and the heat pump inlet pipe 41, and heat exchange for boiling is performed. After being heated in the vessel 62, it becomes hot water and flows into the hot water storage tank 10 from the upper part of the hot water storage tank 10 through the heat pump outlet pipe 42, the four-way valve 32 and the tank upper pipe 43. By performing such boiling-up single operation, high temperature water is stored from the upper layer inside the hot water storage tank 10, and this high temperature water layer gradually becomes thicker.

FIG. 4 is a diagram showing a circuit configuration at the time of a bath water reheating single operation for heating the bath water using the high-temperature water in the hot water storage tank 10 (hereinafter referred to as “a bathtub water reheating single operation using a hot water storage”). It is.
First, from the standby state shown in FIG. 2, in the three-way valve 31, the b port and the c port communicate with each other and the a port is closed (that is, the second flow path configuration of the three-way valve 31 is selected. Controlled). As a result, the use side heat exchanger primary side outlet pipe 46 and the heat pump inlet pipe 41 communicate with each other, and the tank lower pipe 40 side is closed to block the flow path from the lower part of the hot water storage tank 10.

  Further, in the bath water replenishment single operation using hot water storage, the four-way valve 32 is configured so that the b port and the a port communicate with each other and the c port and the d port are closed (that is, the third direction of the four-way valve 32 is the above-described third). Controlled so that the channel configuration is selected. Thereby, the bypass pipe 47 and the tank return pipe 44 communicate with each other, and the communication between the heat pump outlet pipe 42 side and the tank upper pipe 43 side is blocked.

  Furthermore, in the bath water replenishment independent operation using hot water storage, the three-way valve 33 is configured so that the a port and the c port communicate with each other and the b port is closed (that is, the first flow path configuration of the three-way valve 33 is set). To be selected). Thereby, the high temperature water pipe 48 and the use side heat exchanger primary side inlet pipe 45 communicate with each other, and the flow path from the lower part of the hot water storage tank 10 is shut off with the low temperature water pipe 49 side closed.

  The bath water replenishment single operation using hot water storage is executed by starting the operation of the circulation pump 21 with the three-way valves 31, 33 and the four-way valve 32 controlled as described above. As a result, the high-temperature water flowing out from the upper part of the hot water storage tank 10 is guided to the use-side heat exchanger 22 via the high-temperature water pipe 48 and the use-side heat exchanger primary-side inlet pipe 45, and the use-side heat exchanger 22 is used for heat exchange with the bath water, and the hot water after the heat exchange is used on the use side heat exchanger primary side outlet pipe 46, three-way valve 31, circulation pump 21, heat pump inlet pipe 41, bypass pipe 47, four-way valve 32, Via the tank return pipe 44, the hot water storage tank 10 is returned to the hot water storage tank 10 through a return port provided between the central portion and the lower portion.

  At this time, the high temperature water flows out from the upper part of the hot water storage tank 10 and the low temperature water deprived of heat by the use side heat exchanger 22 flows from the central part of the hot water storage tank 10 through the return port provided at the lower part. In the tank 10, the high-temperature water layer is gradually thinned. In addition, the heat pump unit 60 stops operation in the bath water replenishment single operation using hot water storage.

  On the other hand, in the path on the bathtub 50 side, the hot water stretched on the bathtub 50 circulates in the bathtub water circulation circuit 51 by operating the secondary circulation pump 52. As a result, the heat of the high-temperature water flowing through the primary side of the use-side heat exchanger 22 is transmitted to the hot water flowing through the secondary side of the use-side heat exchanger 22, and the hot water stretched in the bathtub 50 is warmed. .

  FIG. 5 is a circuit configuration diagram in the standby state of the waste water recovery operation for bathtub water during the hot water supply operation of hot water storage type hot water heater 100 according to Embodiment 1 of the present invention. First, from the standby state shown in FIG. 2, in the three-way valve 31, the b port and the c port communicate with each other and the a port is closed (that is, the second flow path configuration of the three-way valve 31 is selected. Controlled). As a result, the use side heat exchanger primary side outlet pipe 46 and the heat pump inlet pipe 41 communicate with each other, and the tank lower pipe 40 is closed to block the flow path from the lower part of the hot water storage tank 10.

  Further, in the bath water waste heat recovery operation standby state, the four-way valve 32 communicates with the b-port and the d-port, and the a-port and the c-port are closed (that is, the fourth direction of the four-way valve 32). Controlled so that the channel configuration is selected. Thereby, the bypass pipe 47 and the tank upper pipe 43 communicate with each other, and the flow paths of the heat pump outlet pipe 42 side and the tank return pipe 44 are closed.

  Further, in the bath water waste heat recovery operation standby state, the three-way valve 33 is configured such that the b port and the c port communicate with each other and the a port is closed (that is, the second flow path configuration of the three-way valve 33 is To be controlled). As a result, the low temperature water pipe 49 and the use side heat exchanger primary side inlet pipe 45 communicate with each other, and the high temperature water pipe 48 side is closed and the flow path from the upper part of the hot water storage tank 10 is blocked.

  In this bathtub water waste heat recovery operation standby state, all of the circulation pump 21, the heat pump unit 60, and the secondary side circulation pump 52 are controlled to be stopped. Here, as described above, the hot water storage type water heater 100 of the present embodiment includes the check valve 55 in the middle of the low temperature water pipe 49. For this reason, in the standby state shown in FIG. 5 described above, the high temperature water can be prevented from flowing back through the low temperature water pipe 49 due to the convection due to the specific gravity difference between the high temperature water and the low temperature water.

  The transition from the standby state shown in FIG. 2 to the bathtub water waste heat recovery operation standby state shown in FIG. 5 is based on the condition that the waste water recovery of the bathtub water can be performed. Specifically, for example, when the water flow detection sensor (not shown) for detecting the presence or absence of hot water in the bathtub detects that there is bathtub water after the secondary side circulation pump 52 has been operated for a predetermined time, the bathtub water waste in FIG. Transition to heat recovery operation standby state.

  In particular, when the secondary circulation pump 52 is operated and the detected value of the bathtub inlet thermistor 53 when a predetermined time has passed is detected to be a predetermined value (for example, 35 ° C.) or more, or the detected temperature of the bathtub inlet thermistor 53 and the lower part When the temperature difference of the remaining hot water thermistor 12 is compared to a predetermined value or more, it is preferable that the state immediately transitions to the bath water waste heat recovery operation standby state of FIG. Thereby, when the hot water supply operation occurs next time, it is possible to quickly recover the waste heat.

  FIG. 6 is a circuit configuration diagram during a bath water waste heat recovery operation during the hot water supply operation of hot water storage type hot water heater 100 according to Embodiment 1 of the present invention. When the user opens the faucet or shower, the hot water stored in the upper part of the hot water storage tank 10 and the low temperature water supplied from the water supply pipe 2 are mixed by the hot water supply mixing valve 31 and then the mixed water hot water pipe. Hot water is supplied from the tap 80 via 5. At this time, the opening degree of the hot water supply mixing valve 31 is feedback-controlled so that the temperature of the mixed water detected by the mixed water thermistor 9 becomes a preset temperature.

  When the detected value of the mixed water flow rate sensor 8 becomes equal to or higher than a predetermined value (for example, 2 liters per minute) due to the hot water supply, it is determined that there is hot water supply, and the bath water waste heat recovery operation is started. Specifically, first, the secondary circulation pump 52 is driven. The temperature detected by the bathtub inlet thermistor 53 and the hot water storage tank 10 after a lapse of time (for example, 30 s) from when the secondary side circulation pump 52 is driven until the hot water in the bathtub reaches the bathtub inlet thermistor 53. The temperature detected by the lower hot water thermistor 12 that detects the temperature of the lower part is compared. As a result, when it is determined that the detected temperature of the bathtub inlet thermistor 53 is high, the circulation pump 21 is driven to recover the waste water of the bathtub water.

  When the circulation pump 21 is driven, as shown in FIG. 6, the low temperature water (for example, 10 ° C.) below the hot water storage tank 10 is supplied to the low temperature water pipe 49, the three-way valve 33, the use side heat exchanger primary side inlet pipe 45. In the heat exchanger 22, heat is exchanged with bath water (for example, 40 ° C.) and the temperature is raised. The hot water after the temperature rise (for example, 40 ° C.) passes through the use side heat exchanger primary side outlet pipe 46, the three-way valve 31, the heat pump inlet pipe 41, the circulation pump 21, the bypass pipe 47, the four-way valve 32, and the tank upper pipe 43. Then, it is supplied to the hot water supply pipe 3.

  At this time, the hot water (40 ° C.) after the recovery of the waste water from the bathtub water flowing through the tank upper pipe 43 is mixed with the hot water (for example, 90 ° C.) above the hot water storage tank 10 at the junction of the hot water supply pipe 3 and the tank upper pipe 43. Is done. The mixed high temperature water is supplied to the hot water side piping of the hot water supply mixing valve 6, mixed with the low temperature water from the water supply branch pipe 4 and adjusted to the set temperature, and then discharged from the faucet 80 through the mixed water hot water pipe 5. The

  Note that the flow rate of hot water from the tank upper pipe 43 decreases depending on the flow path resistance and pipe resistance of the heat exchanger 22. For this reason, in the hot water storage type water heater 100 of the present embodiment, when the hot water flow rate after the recovery of the waste water from the bath water from the tank upper pipe 43 is small, the rotational speed of the circulation pump 21 is increased to increase the hot water flow rate. Rotational speed control is performed so that The hot water flow rate after the bath water waste heat recovery can be detected, for example, by providing a flow sensor in the middle of the piping constituting the hot water supply circuit during the bath water waste heat recovery operation. As a result, even if the waste heat recovery flow rate decreases due to the flow path resistance, the waste heat recovery flow rate can be increased by driving the circulation pump 21 used for boiling, and high efficiency can be achieved even in a short hot water supply time. This makes it possible to recover waste heat from bathtub water.

  Further, the rotation speed of the circulation pump 21 during the bath water waste heat recovery operation may be controlled based on the temperature detected by the hot water supply thermistor 13. Specifically, for example, when the temperature detected by the hot water supply thermistor 13 is higher than a preset temperature, it is determined that the passage flow rate (tub water waste heat recovery flow rate) of the tank upper pipe 43 is small, and the operation rotation of the circulation pump 21 is performed. Increase the number. Thereby, since the flow rate of the hot water passing through the heat exchanger 22 is increased and the waste heat recovery capability of the bathtub water is improved, it is possible to realize highly efficient recovery of the waste water from the bathtub water even in a short hot water supply time.

  In this manner, the circulation water flow rate of the bathtub water can be increased by driving the circulation pump 21 and the recovery efficiency is improved, so that the waste heat recovery of the bathtub water can be performed with high efficiency. Energy saving can be realized by using it for hot water supply.

  When the detected value of the mixed water flow rate sensor 8 reaches a predetermined small flow rate, it is determined that the hot water supply has been stopped, and the bathtub water waste heat recovery operation is stopped. However, even if the hot water supply operation is stopped once, it is sufficiently assumed that the hot water supply is started again in a short time. Therefore, in hot water storage type water heater 100 of the first embodiment, when it is determined that hot water supply is stopped, a predetermined standby operation is performed.

  FIG. 7 is a circuit configuration diagram of the hot-water storage type hot water heater 100 according to Embodiment 1 of the present invention during standby operation. As shown in this figure, when shifting from the bath water waste heat recovery operation to the standby operation, the four-way valve 32 is configured so that the b port and the a port communicate with each other and the c port and the d port are closed ( That is, control is performed so that the third flow path configuration of the four-way valve 32 is selected. The driving of the secondary circulation pump 52 and the circulation pump 21 is maintained for a predetermined time.

  During the standby operation controlled as described above, as shown in FIG. 7, the low temperature water (for example, 10 ° C.) in the lower part of the hot water storage tank 10 is supplied from the low temperature water pipe 49, the three-way valve 33, the use side heat exchanger primary side. It flows through the inlet piping 45, heat-exchanges with bathtub water (for example, 40 degreeC) in the heat exchanger 22, and is heated up. The warm water after the temperature rise (for example, 40 ° C.) passes through the use side heat exchanger primary side outlet pipe 46, the three-way valve 31, the heat pump inlet pipe 41, the circulation pump 21, the bypass pipe 47, the four-way valve 32, and the tank return pipe 44. After that, the hot water storage tank 10 is returned again to the return port (second lower part) provided between the central part and the lower part. According to such a standby operation, when the hot water supply operation is resumed within a predetermined time, the four-way valve 32 is communicated with the b port and the d port so that the a port and the c port are closed. By controlling (that is, the fourth flow path configuration of the four-way valve 32 is selected), the bathtub water waste heat recovery operation can be promptly restarted.

  Next, the prohibition conditions for the bathtub water waste heat recovery operation will be described. It is desirable that the conditions for recovering waste heat from the bath water are basically conditions that the user does not take a bath and will not take a bath in the future. The water heater with automatic bath operation function has a function to set the bath time operation with a remote control etc., and when bath automatic operation is set, the bath temperature is kept at the set temperature. It has a function to be.

  At this time, when bath automatic operation is set, the temperature of the bath water drops when the bath water waste heat is performed, so it is clear that the user feels uncomfortable when bathing, so the waste heat recovery of the bath water Prohibit driving. Thereby, the situation which inconveniences a user can be avoided effectively.

  Moreover, the waste heat recovery operation of bathtub water is prohibited when it is determined that the user is taking a bath in the bathtub regardless of whether automatic bath operation is set. For example, bath detection means for detecting a user's bathing in bathtub water is provided, and when a user's bathing is detected, waste water recovery operation (for example, 1 hour) of bath water is prohibited for a predetermined time. The bathing detection means may use a human body detection means such as an infrared sensor or a means for detecting bathing based on a water level rise value at the time of bathing using a water level sensor for detecting the water level of a bathtub. Thereby, it is possible to effectively avoid a situation in which the waste heat recovery operation is performed during bathing by the user when the bath automatic operation is not set.

  As described above, according to the hot water storage type water heater 100 of the first embodiment, the component configuration used for satisfying the functions of the heat pump water heater such as boiling, reheating, and hot water supply is utilized. A heat pump water heater that can efficiently recover waste heat from bathtub water using components of a conventional heat pump water heater without the need to add new components such as heat exchangers and mixing valves. Can be provided.

  By the way, in Embodiment 1 mentioned above, although the heat pump cycle was made into the supercritical heat pump cycle from which the pressure of a refrigerant | coolant becomes more than a critical pressure, of course, the heat pump cycle below a general critical pressure may be sufficient. In this case, chlorofluorocarbon, ammonia, or the like may be used as the refrigerant. This also applies to Embodiment 2 described later.

Embodiment 2. FIG.
8 and 9 are configuration diagrams of hot water storage type hot water supply apparatus 200 according to Embodiment 2 of the present invention. In the figure, detailed description of the same elements as those in the system configuration shown in FIG. 1 is omitted.

  In the hot water storage type water heater 200 shown in FIG. 8, a four-way valve 34 is attached to the position of the three-way valve 33 in the system shown in FIG. 1, and one d port is added. Further, a second bypass pipe 54 is connected between the newly added d-port of the four-way valve 34 and the connection portion between the four-way valve 32 and the hot water supply pipe 3 in the tank upper pipe 43.

  The four-way valve 34 is a flow path switching means having three inlets (a, b, d ports) through which hot water flows and one outlet (c ports) through which hot water flows out. The flow path configuration is configured to be switchable between the −c path, the bc path, and the dc path.

  More specifically, the “first flow path configuration” that can be selected by the four-way valve 34 means that the upper part of the hot water storage tank 10 and the use side heat exchanger 22 are connected to the high temperature water pipe 48 and the use side heat exchanger primary side inlet. It is a flow path form communicating through the pipe 45, and the “second flow path form” means that the lower part of the hot water storage tank 10 and the use side heat exchanger 22 are connected to the low temperature water pipe 49 and the use side heat exchanger primary. It is a flow path form communicating via the side inlet pipe 45, and the “third flow path form” means that the upper pipe 3 and the use side heat exchanger 22 are connected to the second bypass pipe 54 and the use side. This is a flow path form communicating through the heat exchanger primary side piping 45.

  The hot water storage type water heater 200 according to the second embodiment is characterized in that waste heat recovered from bathtub water is used for freeze prevention operation. FIG. 9 is a circuit configuration diagram in the simultaneous operation of the bathtub water waste heat recovery operation and the heat pump piping freezing prevention operation of the hot water storage hot water supply apparatus according to Embodiment 2 of the present invention. As shown in this figure, at the time of simultaneous operation of the bathtub water waste heat recovery operation and the freeze prevention operation, the three-way valve 31 communicates with the b port and the c port so that the a port is closed (that is, three-way). Control is performed so that the second flow path configuration of the valve 31 is selected. As a result, the use side heat exchanger primary side outlet pipe 46 and the heat pump inlet pipe 41 communicate with each other, and the tank lower pipe 40 is closed to block the flow path from the lower part of the hot water storage tank 10.

  In the simultaneous operation of the bathtub water waste heat recovery operation and the freeze prevention operation, the four-way valve 32 is connected to the c port and the d port so that the a port and the b port are closed (that is, the four-way valve is closed). The first flow path configuration of the valve 32 is selected. As a result, the heat pump outlet pipe 42 and the tank upper pipe 43 communicate with each other, and the flow paths of the bypass pipe 47 side and the tank return pipe 44 are closed.

  Further, at the time of simultaneous operation of the bathtub water waste heat recovery operation and the freeze prevention operation, the four-way valve 34 communicates with the c port and the d port so that the a port and the b port are closed (that is, the four-way valve). 34 so that the third channel configuration is selected). As a result, the second bypass pipe 54 and the use side heat exchanger primary side inlet pipe 45 communicate with each other, and the high temperature water pipe 48 side and the low temperature water pipe 49 side are closed to block the flow path from the upper part of the hot water storage tank 10. Is done.

  In the state where the three-way valve 31, the four-way valve 32, and the four-way valve 34 are controlled as described above, it has been detected that the outside air temperature thermistor 67 capable of detecting the outside air temperature is below the temperature at which the heat pump pipe can be frozen. In this case, it is determined that the start condition for the simultaneous operation of the bathtub water waste heat recovery operation and the freeze prevention operation is satisfied, and the simultaneous operation is started. Specifically, the circulation pump 21 is first driven, and then the secondary circulation pump 52 is driven. Then, after the time until the hot water in the bathtub reaches the bathtub inlet thermistor 53 (for example, 30 s), when the detected value of the bathtub inlet thermistor 53 is equal to or higher than a predetermined temperature, the secondary circulation pump 52 Is driven for a predetermined time to transfer the heat of the bathtub water to the circulating water on the heat pump pipe side, so that waste heat of the bathtub water can be used for freezing prevention.

  As described above, according to the hot water storage type water heater 200 of the second embodiment, the component configuration used to satisfy the functions of the heat pump water heater such as boiling, reheating, and hot water supply is utilized. A heat pump water heater that can efficiently recover waste heat from bathtub water using components of a conventional heat pump water heater without the need to add new components such as heat exchangers and mixing valves. Can be provided.

1 Hot water storage tank unit 3 Hot water supply pipe 8 Mixed water flow rate sensor (flow rate detection means)
10 Hot water storage tank 12 Remaining hot water thermistor (low temperature water detection means)
13 Hot water supply thermistor (hot water temperature detection means)
21 Circulating pump 22 Use side heat exchanger 31 Three-way valve (first flow path switching means)
32 Four-way valve (second flow path switching means)
33 Three-way valve (third flow path switching means)
34 Four-way valve (third flow path switching means)
40 Tank lower piping (boiling water circulation circuit)
41 Heat pump inlet piping (boiling water circulation circuit)
42 Heat pump outlet piping (boiling water circulation circuit)
43 Tank upper piping (boiling water circulation circuit)
44 Tank return piping (return piping)
45 Use side heat exchanger primary side inlet piping (heat source side piping)
46 Use side heat exchanger primary side outlet piping (heat source side piping)
47 Bypass piping 49 Low-temperature water piping 50 Bathtub 51 Bathwater circulation circuit 52 Secondary circulation pump (bath circulation pump)
53 Bathtub entrance thermistor (tub water temperature detection means)
55 Check valve (back flow prevention means)
60 Heat pump unit (heating means)
62 Heat exchanger for heating 67 Outside temperature thermistor (outside temperature detection means)
70 control unit (control means, second control means, restriction means, second restriction means)
100, 200 hot water storage hot water supply machine

Claims (7)

A hot water storage tank for storing hot water,
A boiling heat exchanger that heats the water in the hot water storage tank using predetermined heating means to form high-temperature water;
A use side heat exchanger for exchanging heat between hot water in the hot water storage tank and bathtub water in the bathtub;
One end is connected to the lower part of the hot water storage tank, the boiling heat exchanger is installed in the middle, and the other end is connected to the upper part of the hot water storage tank,
One end is connected to the upper part of the hot water storage tank, the use side heat exchanger is installed on the way, and the other end is connected between the lower part of the hot water storage tank and the heating heat exchanger in the boiling water circulation circuit Heat source side piping,
First flow path switching means installed at a connection portion between the boiling water circulation circuit and the other end of the heat source side pipe;
It is a circuit configured in an annular shape from the bathtub, and the bathtub water circulation circuit in which the use side heat exchanger and the bath circulation pump are installed in the middle,
A circulation pump installed between the first flow path switching means and the boiling heat exchanger in the boiling water circulation circuit;
One end is connected between the discharge side of the circulation pump in the boiling circulation circuit and the boiling heat exchanger in the boiling water circulation circuit, and the other end is the heat exchange for boiling in the boiling water circulation circuit. A bypass pipe connected between the vessel and the upper part of the hot water storage tank;
Second flow path switching means installed at a connection portion between the boiling water circulation circuit and the other end of the bypass pipe;
One end is connected to the lower part of the hot water storage tank, and the other end is connected to the heat source side pipe between the use side heat exchanger and the upper part of the hot water storage tank,
A third flow path switching means installed at a connection portion between the other end of the low temperature water pipe and the heat source side pipe;
One end is connected between the upper part of the hot water storage tank and the second flow path switching means in the boiling circulation circuit, and the other end is connected to a hot water supply terminal,
Low temperature water detection means for detecting the temperature of the low temperature water flowing out from the hot water storage tank to the low temperature water pipe;
Bathtub water temperature detecting means for detecting the temperature of the bathtub water flowing out from the bathtub to the bathtub water circulation circuit;
A flow rate detecting means provided in the middle of the hot water supply pipe ,
Before Symbol first and second, operates the third flow path switching means, said third flow path switching means from the lower portion of the hot water storage tank, said use side heat exchanger, the first flow path switching unit, the circulating When the flow rate detecting means detects a flow rate that is equal to or higher than a predetermined flow rate in a state in which a flow path communicating with the hot water supply pipe is formed through the pump and the second flow path switching means in order, the bath circulation pump is driven, control means for detecting temperature by said cold water detecting means drives the circulation pump is lower than the temperature detected by the bath water temperature detecting means,
A hot water storage type water heater characterized by comprising: A hot water supply temperature detecting means for detecting the temperature of the hot water flowing through the hot water supply pipe;
The hot water storage type hot water heater according to claim 1, wherein the control means includes means for controlling the number of revolutions of the circulation pump so that the temperature detected by the hot water supply temperature detection means becomes a predetermined temperature.   The time zone which has set the automatic heat retention function which adjusts the bathtub water in the said bathtub to preset temperature is further equipped with the restriction | limiting means which restrict | limits execution of the operation | movement by the said control means. The hot water storage water heater described.   Bath detection means for detecting the user's bathing into the bathtub is further provided, and when the user's bathing is detected by the bath detection means, second restriction means for restricting execution of the operation by the control means. The hot water storage type water heater according to any one of claims 1 to 3, further comprising: A return pipe having one end connected to a position vertically above the lower part of the hot water storage tank and the other end connected to the second flow path switching means;
When the flow rate detected by the flow rate detection unit becomes less than a predetermined small flow rate during the operation of the control unit, the second flow path switching unit is operated to start the third flow from the lower part of the hot water storage tank. Forming a flow path communicating with the return pipe through the path switching means, the use side heat exchanger, the first flow path switching means, the circulation pump and the second flow path switching means in order, and the circulation The hot water storage type hot water supply apparatus according to any one of claims 1 to 4, further comprising standby means for stopping the bath circulation pump and waiting for a predetermined time while driving the pump. A second bypass pipe having one end connected between the second flow path switching means and the upper part of the hot water storage tank in the boiling circulation circuit, and the other end connected to the third flow path switching means;
An outside air temperature detecting means for detecting the outside air temperature;
When the temperature detected by the outside air temperature detecting means is lower than a predetermined outside air temperature, and when the temperature detected by the bath water temperature detecting means is higher than the predetermined bath water temperature, the first, second and second By operating three flow path means, the utilization side heat exchanger, the first flow path switching means, the circulation pump, the boiling heat exchanger, the second flow path switching means, and the third flow path switching means And a second control means for driving the circulation pump and the bath circulation pump,
The hot water storage type hot water heater according to any one of claims 1 to 5, further comprising:   The backflow prevention means for preventing that hot water distribute | circulates from the said 3rd flow-path switching means in the said low-temperature water piping toward the lower part of the said hot water storage tank is further provided. The hot water storage type water heater according to item 1.

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