JP4228912B2 - Water heater - Google Patents

Description

  The present invention relates to a hot water supply apparatus.

  Some hot water supply devices have conventionally been provided with a hot water storage tank, and further have a plurality of hot water storage tanks (see, for example, Patent Document 1). By the way, the hot-water supply apparatus provided with two hot water storage tanks is set as the structure described, for example in FIG. That is, the hot water storage tank 81 includes a hot water supply hot water storage tank 81a and a water intake hot water storage tank 81b, and the bottom of the hot water supply hot water storage tank 81a and the top of the intake water hot water storage tank 81b are connected by a connecting pipe 82. An outflow pipe 84 is connected to the bottom of the water intake side hot water storage tank 81b to supply low temperature water to the heating source 83, and the hot water heated by the heat source 83 is stored at the top of the hot water supply side hot water storage tank 81a. An inflow pipe 85 for flowing into 81a is connected. In this case, a circulation pump 86 is interposed in the outflow pipe 84. Further, drain pipes 87 and 88 for discharging hot water in the tanks are connected to the bottoms of the hot water storage tanks 81a and 81b. The drain pipes 87 and 88 are provided with drain plugs (drain valves) 89 and 90, respectively.

In the hot water supply apparatus configured as described above, when the circulation pump 86 is driven, low-temperature water flows out from the bottom of the intake-side hot water storage tank 81 b and flows through the outflow pipe 84 as indicated by an arrow A. The heated water flows through the inflow pipe 85 as shown by arrow A and flows into the top of the hot water supply side hot water storage tank 81a. At this time, the hot water in the lower part of the hot water supply side hot water storage tank 81a flows into the upper part of the intake side hot water storage tank 81b through the connecting pipe 82. Thus, hot hot water can be stored in the hot water storage tanks 81a and 81b.
JP 2001-263809 A (FIG. 1)

  By the way, since the drain pipes 87 and 88 connected to the hot water storage tanks 81a and 81b are arranged outside (outdoors), the drain pipes 87 and 88 are frozen when the outside air temperature is low such as in winter. There is a risk. Therefore, conventionally, as shown in FIG. 4, heaters 91 and 91 such as electric heaters are attached to the drain pipes 87 and 88, respectively, and a thermostat (not shown) is provided. However, if such an electric heater or thermostat is used, the power consumption becomes large and the cost is high. Moreover, the number of parts with the device is large and the workability (installability) is poor.

  The present invention has been made to solve the above-described conventional drawbacks, and its object is to prevent freezing of pipes that may be frozen at low cost without using an electric heater or the like. It is in providing the possible hot water supply apparatus.

The hot water supply apparatus of claim 1 includes a hot water supply hot water storage tank 1a and a water intake side hot water storage tank 1b, and further causes low temperature water to flow out from the bottom of the water intake side hot water storage tank 1b. A hot water supply apparatus having a circulation path 9 that is boiled and flows into the top of the hot water supply side hot water storage tank 1a, and branches from the circulation path 9 a branch pipe 22 that discharges the hot water of the intake water storage tank 1b. A drain valve 25 is provided in the vicinity of the branch portion of the branch pipe 22, and a drain pipe 26 for discharging the hot water of the hot water storage tank 1 a is connected to the hot water supply side hot water storage tank 1 a, so that heat between the drain pipe 26 and the circulation path 9 is obtained. In addition to enabling replacement, a temperature detecting means for detecting the temperature of the pipe 26 is provided, and when the detected temperature is lower than the anti-freezing pump operation start temperature, the circulating pump 5 in the circulation path 9 is driven. Above It is characterized by circulating hot water in the tank 1 through the circulation passage 9.

In the hot water supply apparatus according to the first aspect , heat exchange between the drainage pipe 26 for discharging the hot water from the hot water storage tank 1a (the pipe 27 having the possibility of freezing) and the circulation path 9 is possible. Is prevented from freezing. Further, since the branch pipe 22 is branched from the circulation path 9, the hot water in the water intake side hot water storage tank 1 b can be discharged through the branch pipe 22. That is, the drain pipe 24 for discharging the hot water of the intake side hot water storage tank 1b can be constituted by a part of the circulation path 9 from the intake side hot water storage tank 1b to the branch pipe 22 and the branch pipe 22. And the circulation of the hot water in the circulation path 9 can prevent the freezing of the pipe from the intake side hot water storage tank 1b to the branch pipe 22, and the drain valve 25 is provided in the vicinity of the branch pipe 22, The piping from the branch part to the drainage valve 25 is short and can prevent freezing in the meantime. In this way, a part of the circulation path 9 capable of circulating hot water can be used as a drain pipe for draining the hot water in the intake-side hot water storage tank 1b, and the drain pipe can be prevented from freezing. it can.

In the hot water supply apparatus according to claim 2 , even when the circulation pump 5 of the circulation path 9 is driven for a certain period of time, the pipe 27 having the possibility of freezing does not rise above the end temperature of the freeze prevention pump operation. The heating source H is driven to heat the circulating water.

In the hot water supply apparatus according to the second aspect , even when the circulation pump 5 of the circulation path 9 is driven for a certain period of time, the pipe 27 having the possibility of freezing does not rise above the end temperature of the freeze prevention pump operation. Since the circulating water is heated by driving the heating source H, the heat exchange pipe for performing heat exchange with the pipe 27 having the possibility of freezing becomes high in temperature, so that the pipe 27 can be reliably prevented from freezing.

The hot water supply apparatus according to claim 3 is characterized in that the pipe 27 having the possibility of freezing and the pipe 29 for heat exchange are covered with a heat retaining member 30.

In the hot water supply apparatus according to the third aspect, the pipe 27 having the possibility of freezing and the heat exchanging pipe 29 are covered with the heat retaining member 30, so that the pipe 27 having the possibility of freezing can be further prevented from freezing.

The hot water supply apparatus of claim 4 is characterized in that the temperature detected by the temperature detecting means is a circulating water temperature or an outside air temperature.

In the hot water supply apparatus according to the fourth aspect , as a temperature sensor for detecting the circulating water temperature and the outside air temperature in the circulation path 9, during a boiling operation (operation for accumulating hot water in a hot water storage tank) of this type of hot water supply apparatus. A sensor used in various controls such as the above can be used.

According to the hot water supply apparatus of the first aspect , the freezing of the drain pipe for discharging the hot water in the hot water supply side hot water storage tank can be prevented. In addition, a part of the circulation path capable of circulating hot water can be used as a drain pipe for draining the hot water in the intake side hot water storage tank, and the drain pipe can be prevented from freezing. For this reason, freezing of the drain pipe from each hot water storage tank can be prevented stably. Moreover, since a part of the circulation path can be shared with the drain pipe for draining the hot water in the intake side hot water storage tank, the number of pipes can be reduced and the apparatus can be made compact and the cost can be reduced.

According to the hot water supply apparatus of the second aspect, the heat exchanging pipe for exchanging heat with the pipe having the possibility of freezing increases in temperature, and the freezing of the pipe can be reliably prevented. Thereby, the reliability of freeze prevention can be improved.

According to the hot water supply apparatus of the third aspect , it is possible to further prevent the piping that may be frozen from being frozen, and to further improve the reliability of the freeze prevention .

According to the hot water supply apparatus of claim 4 , as a temperature sensor for detecting the circulating water temperature and the outside air temperature in the circulation path, at the time of boiling operation of this type of hot water supply apparatus (operation for accumulating hot water in the hot water storage tank) The sensors used in various controls such as the above can be used, and it is not necessary to newly install for this anti-freezing operation, and the cost can be reduced.

  Next, specific embodiments of the hot water supply apparatus of the present invention will be described in detail with reference to the drawings. FIG. 1 is a simplified view of a main part of a hot water supply apparatus. The hot water supply device includes a hot water storage tank 1a on the hot water supply side (upper side) and a hot water storage tank 1b on the intake side (lower side), and supplies (hot water supply) hot water from the hot water supply side hot water storage tank 1a to a bathtub (not shown). Or supply (hot water) to the kitchen or shower.

  In this case, the bottom of the hot water supply hot water storage tank 1a and the top of the intake water hot water storage tank 1b are connected by the connecting pipe 2. An outflow pipe 3 is connected to the bottom of the intake side hot water storage tank 1b to supply low temperature water to a heating source H, which will be described later, and the hot water heated by the heating source H is connected to the top of the hot water supply side hot water storage tank 1a. Is connected to an inflow pipe 4 through which the water flows into the hot water storage tank 1a. At this time, a circulation pump 5 is interposed in the outflow pipe 3. The inflow pipe 4 includes a main body 6 on the heating source H side and branch portions 8a and 8b branched via a three-way valve 7. One branch portion 8a is connected to the top of the hot water supply side hot water storage tank 1a. The other branch 8b is connected to the bottom of the intake water storage tank 1b. For this reason, low-temperature water flows out from the bottom of the intake-side hot water storage tank 1b at one branching portion 8a of the outflow pipe 3 and the inflow pipe 4, and the low-temperature water is boiled by the heating source H and heated hot-water storage tank 1a. Therefore, the circulation path 9 that flows into the top of the circuit is configured.

  In this case, a heat pump type heat source was used as the heat source H. That is, the heat source unit constituting the heat pump heating source H includes a refrigeration cycle configured by sequentially connecting a compressor, a water heat exchanger, an expansion valve, an evaporator, and the like, although not shown. And the heat exchange path comprised by the said water heat exchanger is formed between the outflow piping 3 and the inflow piping 4, Low-temperature water from the hot water storage tank 1b flows through this heat exchange path, This heat exchange path Is heated.

  In addition, a hot water outlet (hot water pipe) 10 is connected (connected) to the top of the hot water supply side hot water storage tank 1a. Although not shown, the hot water outlet 10 includes, for example, a branch pipe connected to the bath mixing valve and a branch pipe connected to the hot water supply mixing valve. Here, the bath mixing valve mixes hot water from the hot water supply side hot water storage tank 1a and tap water, and supplies the mixed hot water to the bathtub. The hot water supply mixing valve mixes hot water from the hot water supply side hot water storage tank 1a with tap water and supplies the hot water to a kitchen faucet or a shower in a bathroom.

  The hot water storage tanks 1a and 1b are connected to a circulation path 11 in which a circulation pump 12 and a heat exchange path 14 composed of a heat exchanger 13 are interposed. That is, the circulation path 11 includes an outflow path 15 for supplying hot water from the top of the hot water storage tank 1a to the heat exchange path 14, and an inflow path 16 for returning the hot water flowing out of the heat exchange path 14 to the lower side of the hot water storage tank 1b. Have. A circulation pump 12 is interposed in the outflow path 15.

  A recirculation circuit 18 is connected to a bathtub (not shown). That is, the recirculation circulation path 18 includes an outward piping 19 and a return piping 20 connected via a connection adapter provided in the bathtub, and the outward piping 19 and the return piping 20 are connected to the heat exchanger 13. It is connected via a heat exchange path 21 constituted by In addition, a circulation pump (not shown) is interposed in the forward piping 19.

  By the way, the branch pipe 22 is branched from the circulation path 9, and a part of the circulation path 9 from the intake side hot water storage tank 1 b to the branch portion 23 of the branch pipe 22, and the branch pipe 22, warm water in the intake side hot water storage tank 1 b. A drain pipe 24 for discharging (draining) water is configured. Further, the branch pipe 22 is provided with a drain valve 25 in the vicinity of the branch portion 23. A tap water supply path 32 having a pressure reducing valve 37 is connected to the bottom of the intake water storage tank 1b.

  Further, a drainage channel (drainage pipe) 26 provided with a drainage valve 31 is also connected to the hot water supply side hot water storage tank 1a. In this case, water does not flow through the drainage channel 26 except during drainage. For this reason, the pipe 27 is likely to freeze when the outside air temperature is low, such as in winter. Therefore, in this hot water supply apparatus, a part of the circulation path 9 is attached to the pipe 27 that is likely to freeze, and the pipe 27 that may be frozen is used as the heat exchange pipe 29. The piping 27 can be prevented from freezing. In this case, the pipe 27 and the heat exchange pipe 29 that may be frozen are covered with the heat retaining member 30. The heat retaining member 30 is a heat insulating material, and various heat insulating materials such as polystyrene foam, urethane foam, and glass fiber that are generally used for heat insulation of pipes can be used. In this case, the heat retaining member 30 may be configured with only these heat insulating materials, or may be configured with these heat insulating materials and other heat insulating outer coverings.

  In the hot water supply apparatus configured as described above, when the circulation pump 5 is driven, the low temperature water on the bottom side of the intake side hot water storage tank 1b flows out into the outflow pipe 3 and is supplied to the heating source H as indicated by the arrow A. Hot water heated to a high temperature by the heating source H flows into the top of the hot water supply side hot water storage tank 1a as shown by an arrow A through the inflow pipe 4. At this time, warm water on the bottom side of the hot water supply hot water storage tank 1a flows into the top side of the intake water hot water storage tank 1b via the connecting pipe 2. In this way, it is possible to perform a boiling operation in which the hot water on the bottom side of the intake side hot water storage tank 1b is heated by the heating source and flows into the top of the hot water supply side hot water storage tank 1a. You can store hot water. In this boiling operation, since the temperature of the circulating water does not rise so much in the initial stage, the three-way valve 7 is switched so that the hot water that has passed through the heating source H is returned to the water intake side hot water storage tank 1b via the branch portion 8b. If the temperature of the circulating water rises to a predetermined high temperature, the three-way valve 7 is switched to flow into the hot water supply hot water storage tank 1a through the branching portion 8a.

  When the circulation pump 12 is driven, the hot water at the top of the hot water supply side hot water storage tank 1a flows from the outflow path 15 to the heat exchange path 14 as shown by the arrow B in FIG. To the intake side hot water storage tank 1b. That is, the hot water in the hot water storage tanks 1 a and 1 b circulates in the circulation path 11. When the circulation pump of the recirculation circuit 18 is driven, the hot water in the bathtub flows from the forward piping 19 to the heat exchange path 21 as indicated by an arrow C, and the bathtub is passed from the heat exchange path 21 through the return piping 20. To return. That is, the hot water in the bathtub circulates in the recirculation circuit 18. And the hot water from the hot water supply hot water storage tank 1a flowing through the heat exchange path 14 of the circulation path 11 and the hot water from the bathtub flowing through the heat exchange path 21 of the recirculation circulation path 18 exchange heat, and from this bathtub The hot water is heated and returns to the bathtub. For this reason, the reheating operation of the hot water of a bathtub can be performed.

  By the way, when the heating operation is not performed in winter when the outside air temperature is low, as described above, a part of the pipes connected to the hot water storage tank 1 is the pipe 27 that may be frozen. However, in this hot water supply apparatus, a pipe 27 that may be frozen is attached to a part of the circulation path 9, and a part of the circulation path 9 is used as a heat exchange pipe 29, thereby circulating in the circulation path 9. It is possible to prevent freezing by warming the pipe 27 that may be frozen by heat exchange from the hot water.

  In addition, when the temperature of the hot water flowing in the circulation path 9 is sufficiently high and freezing is prevented, it is not necessary to drive the heat pump heating source H, but the temperature of the hot water flowing in the circulation path 9 is low, When freezing is not prevented by circulation of this hot water, it is necessary to drive the heat pump heating source H and perform a boiling operation to increase the temperature of the hot water flowing out from the intake water storage tank 1b. For this reason, in this hot water supply apparatus, temperature detection means (not shown) for detecting (detecting) the temperature of the pipe 27 (which becomes the water distribution pipe 26 in FIG. 1) having the possibility of freezing, the temperature data and the Based on the set value (such as a freeze prevention pump operation start temperature described later), a control unit (not shown) (for example, including a microcomputer) performs the following control. In this case, the temperature of the circulating water in the circulation path 9 is detected and this temperature is regarded as the temperature of the pipe 27, or the outside air temperature detected by a temperature sensor (not shown) for detecting the outside air temperature is used as the pipe 27. It is considered that the temperature. Further, when the circulating water temperature in the circulation path 9 is detected, even if it is the temperature upstream of the heat pump heating source H (incoming water temperature), it is the temperature downstream of the heat pump heating source H (the hot water temperature). Also good. At this time, the temperature sensor constituting the temperature detecting means may be attached to the pipe of the circulation path 9 or may be rushed (inserted) into the pipe.

  As the control, in a state where the boiling operation is stopped, first, the temperature detected by the temperature detection means is compared with a preset freeze-start pump operation start temperature (for example, 3 ° C.). In this case, as the temperature detected by the temperature detecting means, the circulating water temperature or the outside air temperature in the circulation path 9 is used as described above. When the detected temperature detected is lower than the set anti-freezing pump operation start temperature, the circulation pump 5 in the circulation path 9 is driven, and the hot water in the hot water storage tank 1 is passed through the circulation path 9. Circulate. Further, if the detected temperature exceeds the freeze prevention pump operation start temperature, the stopped state is continued as it is. Then, the detected temperature is compared with the freeze prevention pump operation end temperature (for example, 10 ° C.) set higher than the freeze prevention pump operation start temperature, and the detected temperature becomes the freeze prevention pump operation end temperature. When it exceeds, the driving of the circulation pump 5 is stopped. If the detected temperature is lower than the end temperature of the freeze prevention pump operation, the circulation pump 5 is continuously driven. At this time, the driving time from the start of driving the circulation pump 5 is detected by a timer (not shown).

  Next, the circulation pump 5 continues to be driven, and even if the circulation pump 5 has been driven for a predetermined time (for example, 5 minutes) or longer, the detected temperature is higher than the freeze prevention pump operation end temperature. If low, the heat pump type heating source H is driven. Thereby, the hot water flowing through the circulation path 9 is heated. The detected temperature detected by the temperature detecting means is compared with the freeze prevention heat pump operation end temperature (for example, 15 ° C.) set equal to or higher than the freeze prevention pump operation end temperature. If the detected temperature exceeds the freezing prevention heat pump operation end temperature, the heating operation by the heat pump heating source H is stopped. When the detected temperature is lower than the end temperature of the freeze prevention heat pump operation, the heating operation by the heat pump heating source H is continued until the detected temperature exceeds the end temperature of the freeze prevention heat pump operation. This prevents the piping 27 that may be frozen from freezing.

  In the above hot water supply apparatus, the freezing of this pipe is prevented by heat exchange between the hot water flowing through the circulation path 9 and the pipe 27 having a possibility of freezing (pipe that may freeze) connected to the hot water storage tank 1. Can do. For this reason, it is not necessary to use an electric heater or the like, or to separately provide a freezing prevention circulation path that is different from the circulation path 9, and it is possible to reduce costs and improve workability (installability). In addition, the reliability of freeze prevention can be improved.

  Further, since the heat exchange between the drain pipe 26 (which becomes the pipe 27 having the possibility of freezing) for discharging the hot water from the hot water storage tank 1a and the circulation path 9 is enabled, the drain pipe 26 is prevented from freezing. Further, since the branch pipe 22 is branched from the circulation path 9, the hot water in the water intake side hot water storage tank 1 b can be discharged through the branch pipe 22. That is, the drain pipe 24 for discharging the hot water of the intake side hot water storage tank 1b can be constituted by a part of the circulation path 9 from the intake side hot water storage tank 1b to the branch pipe 22 and the branch pipe 22. And the circulation of the hot water in the circulation path 9 can prevent the freezing of the pipe from the intake side hot water storage tank 1b to the branch pipe 22, and the drain valve 25 is provided in the vicinity of the branch pipe 22, The piping from the branch part to the drainage valve 25 is short and can prevent freezing in the meantime. Thus, a part of the circulation path 9 capable of circulating hot water can be used for the drain pipe 26 for draining the hot water in the intake side hot water storage tank 1b, and the drain pipe 26 is prevented from freezing. be able to. In addition, since a part of the circulation path 9 can be shared with a drain pipe for draining the hot water in the intake side hot water storage tank 1b, the number of pipes can be reduced, and the apparatus can be made compact and low in cost. it can. In addition, since the hot water storage tank 1 includes the intake side hot water storage tank 1b and the hot water supply side hot water storage tank 1a, a unique effect of a multi-can type having a plurality of hot water storage tanks (the effect of reducing the product width by reducing the tank diameter). In other words, it is possible to exhibit effects such as installation in a narrow area where a single hot water storage tank can not be installed.

  In particular, in the hot water supply device, when the circulation pump 5 in the circulation path 9 is driven for a certain period of time and the piping 27 having the possibility of freezing does not rise above the end temperature of the freeze prevention pump operation, the heat pump Since the hot water flowing through the circulation path 9 is heated by driving the heat source H, the circulation path 9 for exchanging heat with the pipe 27 having the possibility of freezing is heated to prevent the pipe 27 from freezing. . Thereby, the reliability of freeze prevention can be improved. Further, the antifreezing operation for circulating hot water in the circulation path 9 is usually an operation in which the hot water in the circulation path 9 is not heated, and cost reduction can be achieved. Furthermore, since the pipe 27 having the possibility of freezing and the heat exchanging pipe 29 are covered by the heat retaining member 30, the freezing of the pipe 27 having the possibility of freezing can be further prevented. Thereby, the reliability of freeze prevention can be further improved. Further, the temperature detected by the temperature detecting means is the circulating water temperature, and by detecting these temperatures, it is possible to determine whether or not the pipe 27 having the possibility of freezing is in a state of freezing. For this reason, when there is a possibility of freezing, the anti-freezing operation for driving the circulation pump 5 can be reliably performed. That is, the reliability of the start of the freeze prevention operation is improved, and stable freeze prevention is possible. In addition, as a temperature sensor for detecting the circulating water temperature and the outside air temperature in the circulation path 9, it is used in various controls such as a boiling operation (operation for accumulating hot water in a hot water storage tank) of this type of water heater. Therefore, it is not necessary to install a new sensor for the freeze prevention operation, and the cost can be reduced.

Next, FIG. 2 shows a reference example . In this case, the branch pipe 22 branched from the circulation path 9 is joined to the drain pipe 26 of the hot water supply hot water storage tank 1a, and the drain valve 25 is provided in the junction pipe 33. ing. The drain pipe 26 is provided with a first check valve 35, and the branch pipe 22 is provided with a second check valve 36. That is, the first check valve 35 regulates the flow of hot water flowing out from the intake side hot water storage tank 1b into the outflow pipe 3 of the circulation path 9 into the hot water supply side hot water storage tank 1a, and the second check valve 36 is connected to the hot water supply side. The inflow of hot water flowing out from the hot water storage tank 1a to the drain pipe 26 into the intake water storage tank 1b is regulated.

  In the hot water supply apparatus shown in FIG. 2, some of the pipes connected to the hot water storage tank 1 become pipes 27 that may freeze, and these pipes 27 are attached to a part of the circulation path 9. A part of the circulation path 9 is made into heat exchange pipes 29, 29, thereby preventing freezing by heat exchange with hot water circulating in the circulation path 9. Also in this case, a part of the drain pipe 26 and a part of the merging pipe 33 and the heat exchange pipes 29 and 29 are covered with the heat retaining members 30 and 30, respectively.

In this case, the freeze prevention operation is performed in the same manner as the hot water supply apparatus described in FIG. That is, when the circulating water temperature or the outside air temperature is detected and the freezing operation is necessary, first, the hot water is circulated in the circulation path 9 without heating the hot water circulated by the heat pump heating source. If freezing cannot be avoided by this circulation, the hot water circulated by the heat pump heating source H is then used. For this reason, also in the reference example shown in FIG. 2, the same operational effects as those of the embodiment shown in FIG. 1 can be exhibited. The same components as those of the embodiment shown in FIG.

In addition, in the hot water supply apparatus of FIG. 2 , by operating one drain valve 25, the water (hot water) in each hot water storage tank 1a, 1b can be drained. Thereby, simplification of drainage work can be achieved and workability can be improved by reducing the amount of drainage work. Further, only one drain valve 25 is required, which contributes to a reduction in initial cost. Further, since the first check valve 35 and the second check valve 36 are provided, the hot water at the bottom of the hot water supply hot water storage tank 1a is provided at the bottom of the hot water supply hot water storage tank 1b during the heating operation or hot water supply operation. Does not flow in, nor does the hot water in the lower part of the hot water supply side hot water storage tank 1a flow into the bottom of the intake side hot water storage tank 1b. That is, it is possible to prevent a decrease in hot water temperature of the hot water supply hot water storage tank 1a due to low temperature water inflow from the bottom of the intake water hot water storage tank 1b, and to efficiently store hot water in the hot water supply hot water storage tank 1a. Further, it is possible to prevent the hot water temperature at the bottom of the water intake side hot water storage tank 1b from rising due to the inflow of high temperature water from the hot water supply side hot water storage tank 1a to the bottom of the water intake side hot water storage tank 1b. In particular, when a heat pump type heat source is used as the heat source H, it is possible to prevent an increase in the temperature (incoming water temperature) of the hot water supplied to the heat pump type heat source H, thereby reducing the boiling efficiency during the boiling operation. Therefore, it is possible to prevent a wasteful operation and to reduce the running cost. On the other hand, if the incoming water temperature to the heat pump type heating source rises, the enthalpy difference in the heat dissipation process becomes narrow in the refrigeration cycle, and the boiling operation efficiency decreases.

Next, FIG. 3 shows a reference example , and in this case, it is a canned hot water supply apparatus having one hot water storage tank 1. In this case, the circulation path 9 includes a main body path 9a used during the heating operation and a bypass path 9b connected to the main body path 9a. The main body passage 9a is connected to the bottom of the hot water storage tank 1 and connected to the outflow pipe 40 and the top of the hot water storage tank 1 in order to supply low temperature water to the heating source H and heated by the heating source H. And an inflow pipe 41 through which high-temperature water flows into the hot water storage tank 1. A circulation pump 42 is interposed in the outflow pipe 40. The inflow pipe 41 includes a main body 43 on the heating source H side and branch portions 45a and 45b branched via a three-way valve 44, and one branch portion 45a is connected to the top of the hot water storage tank 1. The other branch 45 b is connected to the bottom of the hot water storage tank 1. For this reason, low temperature water is caused to flow out from the bottom of the hot water storage tank 1, and the low temperature water is boiled by the heat pump heating source H and flows into the top of the hot water storage tank 1.

  Although not shown in FIGS. 1 and 2, the hot water supply passage 10 includes a branch pipe 47 connected to the bath mixing valve 46 and a branch pipe 49 connected to the hot water supply mixing valve 48. Here, the bath mixing valve 46 mixes hot water from the hot water storage tank 1 and tap water from the tap water supply path 50, and supplies the mixed hot water to the bathtub via the supply path 51. Is. The hot water supply mixing valve 48 mixes hot water from the hot water storage tank 1 and tap water from the tap water supply path 50, and supplies the mixed hot water via a supply path 52 to a kitchen faucet or washroom. Hot water is supplied to the shower. Further, the supply path 51 is provided with a valve 53 and is connected to the return pipe 20 of the recirculation circuit 18.

  In this case, as for the circulation path 11 used for reheating, the outflow path 15 provided with the circulation pump 12 is connected to the top of the hot water storage tank 1, and the inflow path 16 is formed on the lower side of the side wall of the hot water storage tank 1. It is connected. Therefore, when the circulation pump 12 is driven, hot hot water flows out from the top side of the hot water storage tank 1 to the outflow path 15 as indicated by an arrow B, and passes through the heat exchange path 14 configured by the heat exchanger 13. It enters the inflow path 16 and returns to the hot water storage tank 1 from the inflow path 16 as indicated by an arrow B. When the circulation pump of the recirculation circulation path 18 is driven, the hot water in the bathtub flows from the forward piping 19 to the heat exchange path 13 as indicated by an arrow C, and the bathtub is passed from the heat exchange path 21 through the return piping 20. To return. For this reason, even in this case, when the circulation pump 12 and the circulation pump of the recirculation circuit 18 are driven, the retreat can be performed.

  Next, the upstream end 55 a of the bypass path 9 b is connected to the main body 43 of the inflow path 41 of the circulation path 9, and the downstream end 55 b of the bypass path 9 b is the outflow path 40 (the hot water storage tank 1 rather than the circulation pump 42). Side). That is, the bypass passage 9 b branches from the main body passage 9 a on the downstream side of the heat pump heating source H and joins the main passage 9 a on the upstream side of the heat pump heating source H. The bypass path 9 b includes a first parallel pipe 56 that follows the branch portion 45 a of the inflow path 41, a second parallel pipe 57 that follows the outlet pipe 10, and a third parallel pipe 58 that follows the supply path 52. , A fourth juxtaposed pipe 59 that follows the supply path 51, a fifth juxtaposed pipe 60 that follows the tap water supply path 50, and a sixth juxtaposed pipe 61. The bypass passage 9 b includes a main body pipe 62 having these juxtaposed pipes 56, 57, 58, 59, 60, 61 and a sub pipe 63 connected to the main body pipe 62. The sub-pipe 63 is provided with a seventh juxtaposed pipe 65 to which the drain pipe 64 of the hot water storage tank 1 is attached.

  In this case, the first juxtaposed pipe 56, the second juxtaposed pipe 57, the third juxtaposed pipe 58, the fourth juxtaposed pipe 59, the fifth juxtaposed pipe 60, the sixth juxtaposed pipe 61, and the seventh juxtaposed pipe 61. Each pipe arranged in parallel with the installation pipe 65 is a pipe 27 that may freeze, and these parallel installation pipes 56 are the heat exchange pipe 29. And the piping 27 which may be frozen and the heat exchange piping 29 are respectively covered with the heat retaining members 30.

  According to the hot water supply device, when the upstream side opening / closing valve 66 is opened in the bypass passage 9b and the circulation pump 42 in the circulation passage 9 is driven, the hot water in the hot water storage tank 1 flows out to the outflow pipe 40 in the circulation passage 9. Then, it flows into the heat pump heating source H and flows into the bypass passage 9b via the heat pump heating source H. And the warm water which flowed into the bypass channel 9b is the first juxtaposed pipe 56, the second juxtaposed pipe 57, the third juxtaposed pipe 58, the fourth juxtaposed pipe 59, the fifth juxtaposed pipe 60, and the sixth juxtaposed pipe 60. It flows through the installation pipe 61 and the seventh parallel installation pipe 65 and returns to the circulation path 9.

  Also in this case, the freeze prevention operation is the same operation as that of the hot water supply apparatus shown in FIGS. That is, when the circulating water temperature (the temperature of the hot water in the bypass passage 9b) and the outside air temperature are detected, and the detected temperature is lower than the antifreezing operation temperature compared with the detected antifreezing operation temperature. First, the heat pump type heating source H is circulated in the bypass 9b without driving the hot water, that is, without heating the hot water. Then, when the detected temperature becomes equal to or higher than the preset freeze prevention pump operation end temperature higher than the freeze prevention pump operation start temperature, the freeze prevention operation is stopped. If the detected temperature does not rise above the freeze prevention pump operation end temperature, the heat pump type heating source H is driven to heat the hot water circulating in the bypass passage 9b, and the detected temperature is the antifreeze pump. The freeze prevention operation is stopped when the freeze prevention heat pump operation completion temperature set equal to or higher than the operation completion temperature is exceeded.

  As described above, according to the hot water supply apparatus, the circulation path 9 branches from the main body path 9a on the downstream side of the heat pump heating source H, in addition to the main body path 9a used during the operation of storing hot water in the hot water storage tank 1. Since the bypass path 9b that joins the main body path 9a is provided on the upstream side of the heat pump heating source H, even if there are many pipes 27 having freezing possibility, heat exchange can be performed corresponding to these. Thereby, the freezing of the piping as the whole hot-water supply apparatus can be prevented, and stable operation can always be performed even in winter when the outside air temperature is low.

  Although specific embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications can be made within the scope of the present invention. For example, in FIG. 1 and FIG. 2, it is a multi-can type having two hot water supply side hot water storage tanks 1a and a water intake side hot water storage tank 1b, and in FIG. 3, it is a single can type having one hot water storage tank 1. However, the present invention is not limited thereto, and when a multi-can type is used, one or a plurality of intermediate hot water storage tanks may be disposed between the hot water supply hot water storage tank 1a and the intake water hot water storage tank 1b. At this time, each intermediate hot water storage tank is connected by a connecting pipe so that warm water flows from the top and warm water flows from the bottom. Also in FIGS. 1 and 2, as shown in FIG. 3, the hot water heated by the heat pump heating source H is provided with a hot water circulation path that is different from the circulation path 9 used during the boiling operation. You may make it provide the piping 29 for heat exchange accompanying the piping 27 which may be frozen in a circulation path. On the other hand, in FIG. 3, a part of the circulation path 9 used during the boiling operation may be attached to the pipe 27 that may freeze as the heat exchange pipe 29. In addition, when the heat exchange pipe 29 and the pipe 27 having the possibility of freezing are attached, the pipes may be brought into contact with each other with a slight gap therebetween. Further, the length dimension for attaching the heat exchange pipe 29 to the pipe 27 that may be frozen can be arbitrarily set as long as the pipe 27 is not frozen. Furthermore, in order to prevent freezing, it is preferable to provide the heat retaining member 30, but such a heat retaining member 30 may not be provided. Further, the pipe 27 that may freeze is not limited to the pipe at the position of each of the above embodiments.

  Furthermore, in the above embodiment, when the circulation pump 5 is driven to perform the freeze prevention operation, the circulating water temperature or the outside air temperature is used as the temperature detected by the temperature detecting means, but of course the piping 27 having the possibility of freezing. It may be used by directly detecting its own temperature. In this case, the antifreezing pump operation start temperature is the same temperature when the circulating water temperature is used, when the outside air temperature is used, and when the temperature of the direct piping 27 itself is used. Alternatively, different temperatures may be used. In short, the circulation pump 5 may be driven when the pipe 27 reaches a temperature at which there is a risk of freezing in order to prevent freezing. In addition, although the heat pump type thing was used as a heating source in the said embodiment, you may use the other heat source unit which uses a heater, a thermal power, etc. Even when the heat pump type is used, dichlorodifluoromethane (R-12), chlorodifluoromethane (R-22), 1,1,1,2-tetrafluoroethane (R-134a) is used as a refrigerant for the refrigeration cycle. Or a natural refrigerant such as carbon dioxide, ethylene, ethane, or nitric oxide.

It is a simplified diagram showing an embodiment of a hot water supply apparatus of the present invention. It is a simplified diagram showing a reference example of the present invention. It is a simplified diagram showing another reference example. It is a simplification figure of the conventional hot-water supply apparatus.

Explanation of symbols

  1, 1a, 1b ... Hot water storage tank, 5 ... Circulation pump, 9 ... Circulation path, 9a ... Main body path, 9b ... Bypass path, 25 ... Drain valve, 26 ... Drain pipe, 27 ... Piping, 29 ... Heat exchange piping, 30 ... Heat insulation material, H ... Heating source

Claims (4)

A hot water supply hot water storage tank (1a) and an intake water hot water storage tank (1b) are provided. Further, low temperature water is allowed to flow out from the bottom of the intake water hot water storage tank (1b), and this low temperature water is supplied by a heating source (H). A hot water supply device having a circulation path (9) for boiling and flowing into the top of the hot water supply side hot water storage tank (1a), wherein the branch for discharging hot water of the intake water storage tank (1b) from the circulation path (9) A drain pipe for branching the pipe (22) and providing a drain valve (25) in the vicinity of the branch portion of the branch pipe (22) to discharge the hot water of the hot water storage tank (1a) to the hot water supply hot water storage tank (1a) (26) is connected to enable heat exchange between the drain pipe (26) and the circulation path (9), and temperature detection means for detecting the temperature of the pipe ( 26 ) is provided, and the detected temperature Is lower than the start temperature of the freeze prevention pump By driving the circulation pump (5) of the circulation passage (9), hot water supply apparatus characterized by circulating through the circulation path (9) to hot water of the hot water storage tank (1). When the circulation pump (5) of the circulation path (9) is driven for a certain period of time and the pipe (27) having the possibility of freezing does not rise above the end temperature of the freeze prevention pump operation, the heating source The hot water supply apparatus according to claim 1, wherein (H) is driven to heat the circulating water. The hot water supply device according to claim 1 or 2, wherein the pipe (27) having the possibility of freezing and the heat exchange pipe (29) are covered with a heat retaining member (30). Any of the water heater of claims 1 to 3, wherein the temperature detected by said temperature detecting means is a circulating water temperature or the outside air temperature.