JP3900174B2 - Water heater - Google Patents

Description

  The present invention relates to a hot water storage type water heater having a bath retreat function.

  Conventionally, as this type of water heater, there is one having a reheating function of a bathtub using hot water of a hot water tank (see, for example, Patent Document 1).

  FIG. 3 shows a schematic view of the water heater described in the publication. As shown in the figure, a heat pump heat source comprising a heat pump cycle comprising a hot water supply heating means 1, a compressor 2, a hot water supply heat exchanger 3 as a radiator, a decompression device 4, and an atmospheric heat exchanger 5 that absorbs atmospheric heat. is there.

  The hot water supply circuit is configured by sequentially connecting the hot water supply heat exchanger 3 and the upper part of the hot water storage tank 6 from the lower part of the hot water storage tank 6. The hot water supply heat exchanger 3 is configured to exchange heat between the refrigerant flowing through the heat pump cycle and the water flowing through the hot water supply circuit.

  When the bath 7 is heated, a bath heat exchanger 8 is provided so that high-temperature water is caused to flow from the upper part of the hot water tank 6 to the bath heat exchanger 8 by the heat source side circulation pump 9, and by the use side circulation pump 10. While the water sent from the bathtub 7 is heated, the hot water tank water whose temperature has been lowered by the bath heat exchanger 8 is returned to the middle part or the lower part of the hot water tank 6.

  In the hot water supply heating operation, as described above, in the bath heat exchanger 8, the water sent from the lower part of the hot water storage tank 6 is heated to a high temperature by the heat pump heat source and stored in the upper part of the hot water storage tank 6.

  At this time, the atmospheric heat exchanger 5 absorbs atmospheric energy. However, when the temperature is low, such as in winter, the temperature of the refrigerant flowing through the atmospheric heat exchanger 5 becomes below freezing point, and frost is formed on the surface of the atmospheric heat exchanger 5. It may be attached. When this attached frost grows, it becomes difficult to absorb atmospheric energy, so a defrosting operation is performed to dissolve this attached frost.

  The defrosting operation is performed by a defrosting circuit indicated by a one-dot chain line 11 in FIG. The defrosting circuit includes a defrosting on-off valve 12 and has a configuration in which the discharge side of the compressor 2 and the inlet side of the atmospheric heat exchanger 5 are connected. The defrosting on / off valve 12 is closed during normal hot water supply heating operation, but the defrosting on / off valve 12 is opened during defrosting operation.

  For example, when a large amount of frost adheres to the atmospheric heat exchanger 5, the compressor 2 is driven, the defrosting opening / closing valve 12 is opened, and a high-temperature refrigerant is passed through the defrosting circuit 11, thereby directly directing the atmospheric heat exchanger 5. The frost adhering to the atmospheric heat exchanger 5 is melted by the heat of the refrigerant. And after melting frost, the defrosting on-off valve 12 is closed and it returns to normal hot water supply heating operation.

On the other hand, in the bath heating operation, when there is a request for bath heating, the heat source side circulation pump 9 and the use side circulation pump 10 are driven and sent from the hot water tank 6 by the bath heat exchanger 8 as described above. The hot water in the bathtub 7 is heated by heat exchange between the hot water and the water sent from the bathtub 7 or the hot water.
JP-A-11-72268

  However, in the conventional configuration, the hot water supply heating operation is temporarily stopped during the defrosting operation. The bath heating operation is continued even while the hot water supply heating operation is stopped.

  Therefore, even if the amount of remaining hot water in the hot water storage tank 6 decreases, the bath heating operation is continued with the normal heating capacity regardless of the remaining hot water amount, and the bath heating operation continues or the hot water supply load overlaps. In addition, there was a problem that the hot water in the hot water tank 6 was exhausted.

  As a specific example, since the hot water supply load is generally concentrated from evening to night, the amount of hot water remaining in the hot water tank 6 is the smallest during this time period. In particular, when a hot water supply to the bathtub 7, a hot water supply load in the kitchen, a shower in the bath or the like is generated simultaneously or continuously, the remaining hot water amount in the hot water tank 6 is extremely reduced.

  In such a case, when frost forms on the atmospheric heat exchanger 5 and a defrosting operation is performed to melt the frost, hot water at a predetermined hot water supply temperature does not come out of the faucet 13 during hot water supply, and hot water runs out.

  In addition, there are problems that the bath heating operation itself cannot be continued, the bath heating capability is extremely reduced, and the temperature of the bathtub 7 is difficult to rise.

  The present invention solves the above-mentioned problems, and when performing a defrosting operation, by reducing the bath heating capacity, the possibility of running out of hot water is reduced, and a situation in which the bath heating operation cannot be continued is avoided and is comfortable. An object is to provide a water heater that improves the performance and convenience.

In order to solve the above conventional problems, the water heater of the present invention, a heat pump cycle which includes a compressor and a hot water supply heat exchanger and the pressure reducing device and the air heat exchanger, the hot water tank to store hot water and circulation pump a hot water supply circuit connected to sequentially ring and said hot water supply heat exchanger, the bath water heating circuit comprising a bath heat exchanger and a bath water of high temperature water and the bathtub of the hot water storage tank to heat the bath water to the heat exchanger the circulation flow rate control means for controlling the circulation amount of the hot water to be tapped from the hot water tank provided in the bath water heating circuit, as well as have a defrosting operation function to melt frost adhering to the air heat exchanger, the defrosting operation Sometimes, the circulation flow rate control means suppresses the circulation amount of hot water discharged from the hot water storage tank .

  As a result, when the defrosting operation and the bath heating operation overlap, the possibility of running out of hot water is reduced by reducing the heating capacity of the bath and reducing the amount of hot water used. You can avoid situations where you can't.

  The hot water heater of the present invention reduces the heating capacity of the bath and reduces the amount of hot water used when the hot water heating operation must be interrupted in order to perform the defrosting operation to dissolve frost adhering to the atmospheric heat exchanger. By reducing the number, it is possible to reduce the possibility of running out of hot water and to avoid the situation in which the bath cannot be rerun, thereby improving comfort and convenience.

The present invention can be implemented in the form described in each claim, the first invention is, store the heat pump cycle, the temperature of water provided with a compressor and the hot water supply heat exchanger and the pressure reducing device and the atmospheric heat exchanger a hot water supply circuit connected to sequentially ring the hot water storage tank and the circulation pump the hot water supply heat exchanger, the bath heat exchanger and a bath water of high temperature water and the bathtub of the hot water storage tank to heat the bath water to the heat exchanger The bath water heating circuit includes a bath water heating circuit and a circulation flow rate control means for controlling the circulation rate of hot water discharged from the hot water tank , and has a defrosting operation function for melting frost attached to the atmospheric heat exchanger. At the same time, during the defrosting operation , the circulation flow rate control means suppresses the circulation amount of hot water discharged from the hot water storage tank .

  As a result, when the defrosting operation and the bath heating operation overlap, the hot water of the hot water tank is used by controlling the heating capacity of the bath, so the possibility of running out of hot water is reduced and the bath heating is performed. Avoiding situations where driving is not possible, it is possible to improve comfort and convenience.

  The second aspect of the invention is particularly the circulation flow rate control means of the first aspect of the invention, wherein the circulation flow rate control means calculates the temperature difference between the temperature of the hot water at the outlet of the bath heat exchanger and the temperature of the bath water flowing to the bath heat exchanger, The circulation amount of the hot water stored in the hot water storage tank is controlled so as to be smaller than when the defrosting operation is not performed.

  This reduces the amount of hot water used in the hot water tank and reduces the possibility of running out of hot water.

  According to a third aspect of the invention, in particular, in the second aspect of the invention, a remaining hot water amount detecting means for detecting a remaining hot water amount of the hot water tank is provided, and the circulation flow rate control means is responsive to the remaining hot water amount of the hot water tank detected by the remaining hot water amount detecting means. Thus, the circulation amount of the hot water stored in the hot water tank is suppressed.

  Accordingly, the hot water of the hot water tank is used by controlling the heating capacity of the bath according to the amount of remaining hot water, so that the possibility of running out of hot water can be reduced.

  According to a fourth aspect of the present invention, in particular, in the second aspect, the circulating flow rate control means stores hot water in the hot water storage tank when the remaining hot water amount of the hot water storage tank detected by the remaining hot water amount detection means is less than a first predetermined value. The control is performed so as to suppress the circulation amount of the hot water.

  As a result, when the remaining hot water amount is less than the first predetermined value, the control means for controlling to reduce the heating capacity of the bath during the defrosting operation is provided, so that the remaining hot water amount in the hot water tank is reduced. When the defrosting operation and the bath heating operation overlap, the bath heating capacity is reduced and the amount of hot water used is reduced, so the possibility of running out of hot water is reduced and the bath heating is reduced. The situation where driving is impossible can be avoided.

  According to a fifth aspect of the invention, in particular, in the third aspect of the invention, the circulating flow rate control means is a second method in which the remaining hot water amount of the hot water tank detected by the remaining hot water amount detection means is smaller than the first predetermined value. The control is performed so as to stop the heating of the bath when it is less than the predetermined value.

  Accordingly, when the defrosting operation is less than the second predetermined value, the control means for controlling the bath heating operation to be stopped is provided, so that hot water corresponding to the minimum hot water supply load is secured. Therefore, the possibility of running out of hot water can be reduced.

  The sixth aspect of the invention includes an alarm device that issues an alarm particularly when the heating of the bath is stopped in the fourth aspect of the invention.

  As a result, the user can be informed that the amount of remaining hot water has decreased, so that it is possible to cope with hot water shortages and improve convenience.

In the seventh aspect of the invention, in particular, in the first to sixth aspects of the invention, the refrigerant sealed in the heat pump is carbon dioxide, so that high temperature and high efficiency and global environmental conservation can be achieved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a configuration diagram of a water heater in the first embodiment of the present invention.

  In FIG. 1, a hot water supply heating means 1 which is a heat source of a hot water heater is a heat pump heat source that constitutes a heat pump cycle including a compressor 2, a hot water supply heat exchanger 3, a decompression device 4, and an atmospheric heat exchanger 5 that absorbs atmospheric heat. is there. Then, carbon dioxide whose refrigerant pressure on the high pressure side is equal to or higher than the critical pressure is used as the refrigerant.

  Water is supplied to the hot water tank 6 through a water supply pipe 14 connected to the lower part of the hot water tank 6, and hot water at the upper part of the hot water tank 6 passes through the hot water pipe 15 and is mixed with the supplied water at the mixing valve 16 to a predetermined temperature. Then, the hot water is supplied from a hot water supply terminal (for example, the faucet 13) through the hot water supply pipe 17.

  In addition, by forming a hot water supply circuit that sequentially connects the lower part of the hot water tank 6 to the circulation pump 18, the hot water heat exchanger 3 and the upper part of the hot water tank 6, the water sent from the hot water tank 6 by the circulation pump 18 is Hot water is stored in the hot water storage tank 6 by being heated by the refrigerant heat in the hot water supply heat exchanger 3.

  The boiling temperature detecting means 19 is provided at the water-side outlet of the hot water supply heat exchanger 3 in order to detect the hot water temperature heated by the heat pump heat source.

  The bath heating means 20 includes a bath heat exchanger 8 which is a water / water heat exchanger, a heat source side and a use side water circuit connected thereto, and a heat source side circulation pump 9 and a use side circulation respectively provided in the water circuits. It consists of a pump 10 and the like. Heating of the bathtub 7 is sent from the hot water tank 6 to the bath heat exchanger 8 by the heat source side circulation pump 9 and from the bathtub 7 to the bath heat exchanger 8 by the use side circulation pump 10. This is done by exchanging heat with warm water or hot water.

  The hot water tank 6 is provided with first remaining hot water temperature detecting means 21 for detecting the surface temperature. Furthermore, the control means 22 controls the heating capacity in the bath heating means 20.

  About the hot water heater comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  In FIG. 1, first, the hot water supply heating operation will be described. When there is a hot water supply heating request for storing hot water in the hot water storage tank 6, a hot water supply heating operation using atmospheric heat is performed with a heat pump heat source. In this case, a high-temperature and high-pressure refrigerant discharged from the compressor 2 at a temperature higher than the critical pressure flows into the hot water supply heat exchanger 3, where heat is exchanged with the water sent from the lower part of the hot water storage tank 6 to dissipate the heat. The pressure is reduced by the apparatus 4, and the atmospheric heat exchanger 5 absorbs heat from the atmosphere, gasifies it, and returns to the compressor 2.

  At this time, the number of revolutions of the circulation pump 18 is controlled so that the outlet water temperature of the hot water supply heat exchanger 3 becomes a predetermined temperature with the high-temperature refrigerant flowing into the hot water supply heat exchanger 3, and hot water of a predetermined temperature is It flows in from and is stored.

  In addition, the method of flowing the refrigerant and water in the hot water supply heat exchanger 3 is an opposite flow. The hot water supply heating request includes a request to boil the entire hot water storage tank 6 until it becomes hot water, a request to secure a predetermined remaining hot water amount, and the like.

  Among these, the hot water supply heating operation in which the amount of remaining hot water is reduced to ensure a predetermined amount of remaining hot water will be described. First remaining hot water temperature detecting means 21 is provided at a position of the predetermined remaining hot water amount. When there is a hot water supply load such as a hot water bath and the amount of remaining hot water decreases, it is detected that there is no remaining hot water at the position of the first remaining hot water temperature detecting means 21 provided on the surface of the hot water tank 6. A heating request is made and a hot water supply heating operation is performed.

  The position where the first remaining hot water temperature detecting means 21 is provided should be set in consideration of running out of hot water from the hot water supply load immediately after pouring the bath, which is a hot water filling of the bathtub 7, the bath heating load and the hot water supply heating capacity. That's fine.

  The presence or absence of remaining hot water at the position where the first remaining hot water temperature detecting means 21 is provided is determined by whether the temperature at the position where the first remaining hot water temperature detecting means 21 is provided is higher or lower than a predetermined temperature. do it.

  For example, when the first remaining hot water temperature detecting means 21 detects 50 ° C. or more, it is determined that there is remaining hot water in the hot water tank 6, and if less than 50 ° C. is detected, it is determined that there is no remaining hot water in the hot water tank 6.

  Next, a defrosting operation for melting frost attached to the atmospheric heat exchanger 5 in the hot water supply heating operation will be described. Frost detection means 23 is provided on the refrigerant outlet side of the atmospheric heat exchanger 5. As the frost detection means 23, for example, a detection means for detecting the temperature of the refrigerant at the outlet of the atmospheric heat exchanger 5 is used. If hot water supply heating operation is performed at a low outside air temperature, frost may adhere to the atmospheric heat exchanger 5.

  If frost begins to form at one end, the temperature of the refrigerant in the atmospheric heat exchanger 5 decreases, so that frost is more likely to adhere. As frost adhesion progresses, the temperature of the refrigerant in the atmospheric heat exchanger 5 decreases, and the hot water supply heating performance also gradually decreases. Therefore, when the temperature of the refrigerant at the outlet of the atmospheric heat exchanger 5 detected by the frost detection means 23 is equal to or lower than a predetermined temperature (defrosting start temperature), a defrosting operation for melting frost attached to the atmospheric heat exchanger 5 is performed. Do.

  The defrosting operation is performed by stopping the circulation pump 18, opening the defrosting on / off valve 12, and driving the compressor 2, and the frost attached to the atmospheric heat exchanger 5 is melted by the high-temperature refrigerant.

  At this time, it is better to close the decompression device 4 or reduce the opening as much as possible. And if the temperature of the refrigerant | coolant of the atmospheric heat exchanger 5 exit which the frosting detection means 23 detects becomes higher than 0 degreeC, it will be judged that the frost melt | dissolved, a defrost operation is stopped, and a hot water supply heating operation is restarted.

  Furthermore, the normal bath heating operation (when not in the defrosting operation) will be described. Now, when there is a bath heating request for heating the bath, the control means 22 drives the use side circulation pump 10 and the heat source side circulation pump 9. And the water sent from the bathtub 7 by the use side circulation pump 10 is heated by exchanging heat with the hot water in the upper part of the hot water tank 6 sent by the heat source side circulation pump 9 in the bath heat exchanger 8. Return to bathtub 7.

  Here, when the heat source side inlet water temperature of the bath heat exchanger 8, that is, the temperature of the upper part of the hot water storage tank 6 is the same, generally, the heat source side circulation pump 9 has a larger heating capacity of the bath, The temperature of hot water that radiates heat in the bath heat exchanger 8 and returns to the lower part of the hot water tank 6 is also high. On the other hand, the heat source side circulation pump 9 having a smaller flow rate has a smaller heating capacity of the bath, and the temperature of the hot water radiated by the bath heat exchanger 8 and returned to the lower part of the hot water tank 6 is also lower.

In addition, when the flow rate of the heat source side circulation pump 9 is the same, generally, the temperature of the upper part of the hot water storage tank 6 is higher, that is, the case where the temperature of the heat source side inlet water of the bath heat exchanger 8 is higher. The temperature of the hot water returned to the lower part of the hot water tank 6 after being radiated by the bath heat exchanger 8 is also high. vice versa,
When the temperature of the upper part of the hot water tank 6 is low, that is, when the water temperature at the heat source side of the bath heat exchanger 8 is lower, the heating capacity of the bath is smaller. The temperature of the returning hot water is also low.

  And the hot water which returned to the hot water storage tank 6 lower part is heated to predetermined temperature by the hot-water supply heating operation mentioned above as needed, and is stored in the upper part of the hot water storage tank 6. The operation efficiency at the time of this hot water supply heating operation deteriorates when the inlet water temperature of the hot water supply heat exchanger 3, that is, the temperature of the lower part of the hot water storage tank 6 increases.

  Thus, the larger the bath heating capacity is, the better. The hot water at the upper part of the hot water tank 6 is radiated by the bath heat exchanger 8 and then returns to the lower part of the hot water tank 6, but the return The temperature affects the performance of the subsequent hot water heating operation.

  Furthermore, if the temperature returning to the hot water tank 6 is high, not only the efficiency of the subsequent hot water heating operation is deteriorated, but also the heat energy possessed by the hot water is not sufficiently used. On the other hand, if the temperature returning to the hot water tank 6 is too low, the bath heating capacity is insufficient, and the temperature of the bathtub 7 does not rise easily.

  Therefore, as shown in FIG. 1, a heat source side outlet temperature detecting means 24 for detecting the heat source side outlet temperature of the bath heat exchanger 8 and a usage side inlet temperature detecting means 25 for detecting the usage side inlet temperature of the bath heat exchanger 8; And the flow rate of the hot water on the heat source side is controlled by the temperature difference between the two.

  For example, if the temperature difference ΔT = 5 (K) is controlled to be constant, the return temperature to the hot water tank 6 can be made relatively low even if the temperature of the bathtub 7 changes, and the bath heating is performed. Capability can also be relatively large.

  That is, the control means 22 detects the heat source side outlet temperature and the use side inlet temperature of the bath heat exchanger 8 obtained from the heat source side outlet temperature detection means 24 and the use side inlet temperature detection means 25, and the temperature of both of them. The rotational speed of the heat source side circulation pump 9 is controlled so that the difference becomes 5K.

  Next, the bath heating operation during the defrosting operation will be described. When the frost detection means 23 detects a temperature equal to or lower than the above-described defrost start temperature, the defrost operation is performed. At the same time, a defrosting start signal is sent to the control means 22, and the control means 22 controls the rotation speed of the heat source side circulation pump 9 so that the bath heating capacity is reduced.

  That is, the heat source side outlet temperature and the usage side inlet temperature of the bath heat exchanger 8 obtained from the heat source side outlet temperature detection means 24 and the usage side inlet temperature detection means 25 are detected, and the temperature difference between the two is normal (excluded). The rotational speed of the heat source side circulation pump 9 is suppressed so that the temperature difference (for example, 2K) is smaller than 5K in the bath heating operation (when the frost operation is not being performed).

  The temperature difference may be set based on the temperature of the upper part of the hot water tank 6 supplied as a heat source to the bath heat exchanger 8, the required amount of heating heat of the bathtub 7, the heating capacity of the hot water heating means 1, and the like. .

  In addition, in order to reduce the bath heating capability as described above, a method other than controlling the number of revolutions of the heat source side circulation pump 9 may be performed. Since the heating capacity of the bath heat exchanger 8 is determined by the flow rate on the heat source side and the flow rate on the use side, either the number of revolutions of the heat source side circulation pump 9 or the number of revolutions of the use side circulation pump 10 or both. Can be controlled to reduce the heating capacity of the bath heat exchanger 8.

Further, the configuration of FIG. 1 does not include means for directly measuring the flow rate, but it is only necessary to indirectly measure the change in the flow rate by measuring the change in the outlet temperature on the heat source side. That is, in order to reduce the bath heating capacity, the heat source side outlet temperature of the bath heat exchanger 8 may be controlled to be lower than that in the normal bath heating operation (when not in the defrosting operation). .

  That is, the control means 22 detects the heat source side outlet temperature of the bath heat exchanger 8 obtained from the heat source side outlet temperature detection means 24, and this temperature is the normal (when not in the defrosting operation) bath heating operation. The number of rotations of the heat source side circulation pump 9 is controlled so as to be lower than the heat source side outlet temperature.

  In addition, since the heat source side exit temperature is lowered and returned to the hot water storage tank 6, the amount of heat possessed by the hot water storage tank 6 is used more effectively.

  For example, the upper temperature of the hot water tank 6 is 65 ° C. and the temperature of the bathtub 7 is 42 ° C. In the case of normal (when not in the defrosting operation) bath heating operation, the temperature difference ΔT = 5 (K) between the heat source side outlet temperature of the bath heat exchanger 8 and the use side inlet temperature, and in the case of the defrosting operation If the temperature difference is 2 (K), the heat source side outlet temperature of the bath heat exchanger 8 is 47 ° C. and 44 ° C., respectively.

  At this time, the amount of heat utilized effectively among the amount of heat stored in the hot water storage tank 6 is expressed by the following ratio. In other words, (the amount of heat used when the temperature difference is 5 (K)) :( the amount of heat used when the temperature difference is 2 (K)) = (65−47) :( 65−44). About 17% can be used effectively.

  As described above, when the hot water heating operation cannot be performed due to the defrosting operation, the amount of hot water used in the hot water storage tank 6 is reduced by controlling the bath heating capacity to be small. And avoiding a situation where the bath cannot be heated.

  Moreover, since the temperature of the hot water returning to the hot water tank 6 is made lower than usual, the thermal energy of the hot water stored can be used effectively. Furthermore, the efficiency of the hot water supply heating operation when boiling the hot water returned to the hot water tank 6 again is improved.

(Embodiment 2)
FIG. 2 is a configuration diagram of a water heater in the second embodiment of the present invention.

  In FIG. 2, the difference from the first embodiment is that a second remaining hot water temperature detecting means 26 is provided on the surface of the hot water tank 6 as a remaining hot water amount detecting means. The position of the second remaining hot water temperature detecting means 26 is the same position as the position where the first remaining hot water temperature detecting means 21 is provided or a position where the remaining hot water amount is small (upward).

  About the hot water heater comprised as mentioned above, the operation | movement and an effect | action are demonstrated below. Since the hot water supply heating operation and the defrosting operation are the same as those in the first embodiment of FIG. 1, detailed description thereof is omitted.

  In the defrosting operation illustrated in FIG. 1, the defrosting circuit 11 including the defrosting opening / closing valve 12 is used for defrosting. However, the basic defrosting circuit is not added as a basic defrosting circuit. It is also possible to defrost only with the refrigerant circuit. That is, the circulation pump 18 is stopped, the decompression device 4 is opened, the compressor 2 is driven, and frost adhering to the atmospheric heat exchanger 5 is melted with a high-temperature refrigerant. In addition, it is better to enlarge the opening degree of the decompression device 4 as much as possible.

  Next, the bath heating operation will be described. If the amount of remaining hot water is larger than the position where the second remaining hot water temperature detecting means 26 is provided, the normal (defrosting operation) described in the first embodiment is performed regardless of whether or not the defrosting operation is being performed. Perform bath heating operation (if not in the middle).

  If the hot water supply load is large or the bath heating operation is further continued, the amount of remaining hot water becomes smaller than the position where the second remaining hot water temperature detecting means 26 is provided, and the first defrosting operation is not being performed. The normal bath heating operation (when not in the defrosting operation) described in the embodiment is performed.

  On the other hand, if the amount of hot water is less than the position where the second remaining hot water temperature detecting means 26 is provided and the defrosting operation is being performed, the bath heating operation during the defrosting operation described in the first embodiment is performed. That is, the control means 22 detects the remaining hot water temperature by a signal from the second remaining hot water temperature detection means 26 and detects that there is no remaining hot water at the position where the second remaining hot water temperature detection means 26 is provided. If it does so, the rotation speed of the heat source side circulation pump 9 will be suppressed so that bath heating capability may decrease.

  As described above, when the hot water supply heating operation cannot be performed due to the defrosting operation and the remaining hot water amount in the hot water storage tank 6 is further reduced, the hot water storage tank 6 is controlled by reducing the bath heating capacity. Since the amount of hot water used can be reduced, the possibility of running out of hot water is reduced, and a situation where the bath cannot be heated is avoided.

  As described above, if the bath heating capacity is reduced when the amount of remaining hot water becomes smaller than the position where the second remaining hot water temperature detecting means 26 is provided, the rate of decrease in the remaining hot water amount can be reduced.

  By the way, even if the decrease rate of the remaining hot water amount is reduced, if this continues for a long time or there is a large amount of hot water supply load, the remaining hot water amount may decrease and the hot water may run out.

  Therefore, a third remaining hot water temperature detecting means 27 is provided as a remaining hot water amount detecting means at a position above the position where the second remaining hot water temperature detecting means 26 is provided.

  The position of the 3rd remaining hot water temperature detection means 27 is provided in the place which can cover the minimum hot water supply load. When the amount of remaining hot water becomes smaller than the position where the third remaining hot water temperature detecting means 27 is provided, the control means 22 stops the use side circulation pump 10 and the heat source side circulation pump 9 until hot water is stored in the hot water storage tank 6 again. To stop the bath heating operation.

  Further, by providing the alarm device 28, the user can be notified of the stop of the bath heating operation when the amount of remaining hot water decreases. As a method of notifying the user, the fact may be notified by voice, an alarm sound may be emitted, or displayed on the screen. Further, even if a special device is not provided as the alarm device 28, if the water heater has a remote controller (not shown), it can be shared by adding an alarm function to the remote controller.

  In the above description, the bath heating capacity is controlled by using the second and third remaining hot water temperature detecting means 26 and 27 as the remaining hot water amount detecting means, but the remaining hot water for detecting the temperature of the hot water storage tank 6 is also used. It is also possible to provide a temperature detection means and finely control the capability, and the same operation and effect can be obtained.

  Furthermore, when controlling the bath heating capacity, the rotational speed of the heat source side circulation pump 9 was controlled in order to adjust the circulation amount of the hot water stored in the hot water tank 6, but a flow rate control valve (not shown) The same action and effect can be obtained even if the amount of hot water circulated is adjusted using.

  Moreover, in Embodiment 1 and Embodiment 2, the use-side circulation pump 10 is connected to the bathtub 7, but besides the bathtub 7, a heat radiating unit for performing heating, floor heating, and bathroom drying heating is connected. May be.

Moreover, high temperature hot water (approximately 90 ° C.) can be stored in the hot water storage tank 6 by using carbon dioxide as the refrigerant sealed in the heat pump heat source. Therefore, the heat storage amount of the hot water storage tank 6 increases, and the heating amount and operation time in the bath heating operation increase. It also contributes to global environmental conservation.

  As described above, when the defrosting operation and the bath heating operation overlap, the water heater according to the present invention is capable of running out of hot water by reducing the heating capacity of the bath and reducing the amount of hot water used. Because it is possible to improve the comfort and convenience by avoiding the situation where the bath can not be operated by heating, it is not limited to bath heating, but also heating and bathroom using hot water storage It can also be applied to uses such as dryers.

Configuration diagram of a water heater in Embodiment 1 of the present invention Configuration diagram of a water heater in Embodiment 2 of the present invention Configuration of a conventional water heater

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hot-water supply heating means 2 Compressor 3 Hot-water supply heat exchanger 4 Depressurization device 5 Atmospheric heat exchanger 6 Hot water storage tank 11 Defrost circuit 20 Bath heating means 22 Control means 23 Frosting detection means

Claims (7)

Compressor and the hot water supply heat exchanger and a heat pump cycle provided with a pressure reducing device and the air heat exchanger, and a hot water supply circuit connected to sequentially ring the hot water storage tank and the circulation pump the hot water supply heat exchanger to store warm water, the A bath water heating circuit having a bath heat exchanger that heats hot water in the hot water tank and bath water in the bathtub to heat the bath water, and a circulation flow rate control that controls the circulation amount of the hot water discharged from the hot water tank comprising means to the bath water heating circuit, as well as have a defrosting operation function to melt frost adhering to the air heat exchanger, the defrosting operation times, circulating the circulation flow rate control means of the hot water to be tapped from the hot water tank A water heater that reduces the amount. The circulation flow rate control means stores hot water so that the temperature difference between the temperature of the hot water at the outlet of the bath heat exchanger and the temperature of the bath water flowing to the bath heat exchanger is smaller than when the defrosting operation is not performed. The hot water heater according to claim 1, which controls the circulation amount of hot water stored in the tank. A remaining hot water amount detecting means for detecting the remaining hot water amount in the hot water tank is provided, and the circulation flow rate control means suppresses the circulating amount of hot water stored in the hot water tank according to the remaining hot water amount of the hot water tank detected by the remaining hot water amount detecting means. The water heater according to claim 2. The hot water supply according to claim 3, wherein the circulation flow rate control means suppresses the circulation amount of the hot water stored in the hot water storage tank when the remaining hot water amount of the hot water storage tank detected by the remaining hot water amount detection means is less than a first predetermined value. Machine. The circulating flow rate control means stops the heating of the bath when the remaining hot water amount of the hot water storage tank detected by the remaining hot water amount detecting means is smaller than a second predetermined value that is smaller than the first predetermined value. The water heater according to claim 4. The hot water heater according to claim 5, further comprising an alarm device for notifying that the bath has been stopped when heating of the bath is stopped. The water heater according to any one of claims 1 to 6, wherein the refrigerant sealed in the heat pump is carbon dioxide.

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