JP3663976B2 - Heat pump bath water heater - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement of an apparatus that uses a heat pump to utilize atmospheric heat, solar heat, or the like for heating bath water, or uses atmospheric heat, solar heat, or bath water temperature for heating hot water.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, there has been provided an apparatus that heats hot water from an external heat source using a heat pump cycle to heat hot water and bath tub water.
[0003]
In FIG. 11, the structure of the apparatus which uses the heat of the bath tub water of a prior art example or atmospheric heat as a heat source and heats hot water supply or bath tub water with a heat pump is shown. The heat pump water heater of FIG. 11 includes a compressor 1, expansion valves 2a and 2b, a refrigerant circuit 3, a hot water supply heat exchanger 4, a hot water supply circuit 5, a hot water storage tank 6, a bath heat exchanger 7, A bathtub water circuit 8, a bathtub 9, a heat collector 10 that collects atmospheric heat or solar heat, refrigerant circuit on / off valves 11a, 11b, and 11c that open and close the refrigerant circuit 3, and a bathtub water pump 12 that circulates the bathtub water. Has been.
[0004]
When the hot water heating operation is performed using the temperature of the bathtub water, the following operation is performed. First, the bathtub water circulation pump 12 circulates the bathtub water in the bathtub 9 through the bathtub water circuit 8 and the bath heat exchanger 7. Then, the compressor 1 is operated to pressurize the refrigerant in the refrigerant circuit 3 to a high temperature and a high pressure, and the hot water supply heat exchanger 4, the expansion valve 2a, and the bath heat exchanger 7 are sent in this order. The refrigerant absorbs heat from the bath water in the bath heat exchanger 7 and is then sucked into the compressor 1 and pressurized to high temperature and high pressure, and condensed in the hot water supply heat exchanger 4 to heat the hot water.
[0005]
When the bath water heating operation of the bathtub 9 is performed, the following operation is performed. First, the bathtub water in the bathtub 9 is circulated through the bathtub water circuit 8 and the bath heat exchanger 7 by the bathtub water pump 12. And the compressor 1 is drive | operated and the refrigerant | coolant in the refrigerant circuit 3 is pressurized to high temperature / high pressure, and it sends in order of the bath heat exchanger 7, the expansion valve 2b, and the heat collector 10. FIG. The refrigerant absorbs atmospheric heat with the heat collector 10 and is then pressurized to a high temperature and high pressure with the compressor 1, condensed in the bath heat exchanger 7, and heated in the bath water.
[0006]
In the configuration of this conventional heat pump bath water heater, for example, a method as described in Japanese Patent Publication No. 8-27079 has been proposed in order to efficiently cool and heat bath water. Furthermore, as an application development of a heat pump, Japanese Patent Application Laid-Open No. 9-159267 describes that bath water temperature heat is used for heating.
[0007]
[Problems to be solved by the invention]
However, in the conventional configuration as described above, it has been difficult to effectively use the temperature of the bath water for heating hot water for the following reasons.
[0008]
That is, since the temperature of the bath water absorbed from the refrigerant in the bath heat exchanger 7 is lower than the temperature of the bath water in the bath 9, there is a density difference between both bath waters, and the low-temperature bath water having a high density and low temperature. Flows toward the bottom of the bathtub 9. Therefore, the low-temperature bathtub water returned from the bath heat exchanger 7 forms a low-temperature layer at the bottom of the bathtub 9 without being sufficiently stirred with the high-temperature bathtub water of the bathtub 9. Accordingly, the bathtub water in the bathtub has a temperature distribution such that the temperature at the bottom of the bathtub 9 is low and the temperature at the top of the bathtub is high, as shown in FIG. If the operation is continued as it is, the low temperature layer at the bottom of the bathtub 9 will increase in thickness, and when the bath water outlet of the bathtub is reached, the temperature of the bath water flowing into the bath heat exchanger 7 will drop significantly. To do. When the temperature of the bath water flowing into the bath heat exchanger 7 decreases, not only the efficiency of the heat pump decreases, but also the circulating bath water freezes after being absorbed, so the hot water at the upper part of the bath is effectively supplied. The heat pump operation must be terminated without being available for heating. Therefore, in order to effectively use the heat of the upper part of the bathtub for heating the hot water supply, the problem is that the temperature distribution formed in the bathtub 9 shown in FIG. 12 must be uniform.
[0009]
[Means for Solving the Problems]
In order to solve the above problems, the present invention provides a heat pump circuit having a compressor, a bathtub, a hot water supply circuit having a hot water supply heat exchanger for exchanging heat between the refrigerant of the heat pump circuit and hot water, a bathtub water pump, and the above A bath water circuit having a bath heat exchanger that recovers the heat of the bath water with a refrigerant of the heat pump circuit; and a branch water circuit branching from the middle of the bath heat exchanger; and a bath water outlet of the bath heat exchanger; A bypass circuit that is connected, a bypass circuit on-off valve that opens and closes the bypass circuit, and a control means that controls the bypass circuit on-off valve in relation to the temperature difference between the upper and lower water in the bathtub. When the difference between the upper and lower temperature of the bathtub water becomes a predetermined value or more, a part of the bathtub water being absorbed by the bath heat exchanger by the action of the bathtub water pump flows through the bypass circuit. The bath heat exchanger is circulated in the circulation system together with the rest of the bath water that has flowed, thereby suppressing the drop in the bath water temperature returning to the bath and returning to the bath by a short circulation path via a bypass circuit. The total circulation amount of the bath water is increased to stir the bath water in the bath so as to reduce the vertical temperature difference .
[0010]
According to the said invention, when performing the heating operation of hot water supply using the hot water of bathtub water, the temperature distribution that the temperature of the bottom part of a bathtub is low and the temperature of the upper part of a bathtub is high can be equalized.
[0011]
Therefore, the temperature of the bath water can be effectively and efficiently used for heating hot water.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention include a heat pump circuit having a compressor, a bathtub, a hot water supply circuit having a hot water heat exchanger for exchanging heat between the refrigerant of the heat pump circuit and hot water, a bathtub water pump, and the heat pump circuit. A bath water circuit having a bath heat exchanger that recovers the heat of the bath water with a refrigerant, and the bath water circuit branched from the middle of the bath heat exchanger, and connected to the bath water outlet of the bath heat exchanger A bypass circuit, a bypass circuit on-off valve for opening and closing the bypass circuit, and a control means for controlling the bypass circuit on-off valve in relation to the temperature difference between the upper and lower sides of the bathtub water in the bathtub, and the bathtub water in the bathtub When the temperature difference between the top and bottom of the water becomes greater than or equal to a predetermined value, a portion of the bath water being absorbed by the bath heat exchanger is caused to flow through the bypass circuit by the action of the bath water pump, and bath heat exchange is performed. By circulating the whole of the vessel in the circulation system together with the rest of the bathtub water that has flowed, the temperature of the bathtub water returning to the bathtub is suppressed, and the total amount of bathtub water returning to the bathtub by a short circulation path via the bypass circuit is reduced. The amount of circulation was increased to stir the bath water in the bath so as to reduce the temperature difference between the top and bottom.
[0013]
The difference in the vertical temperature of the bathtub water in the bathtub is, for example, estimated from the operation time or detected based on the temperature of the bathtub water in the bathtub water circuit. In addition, it can be detected based on the pressure of the bath water flowing through the bath heat exchanger or the temperature or pressure of the refrigerant flowing through the bath heat exchanger.
[0014]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
[0015]
(Example 1)
FIG. 1 schematically shows a configuration of a heat pump bath water heater in an embodiment of the present invention. The heat pump bath water heater of the present embodiment includes a compressor 1, an expansion valve 2a, 2b, a refrigerant circuit 3, a hot water heat exchanger 4, a hot water circuit 5, a hot water storage tank 6, a bath heat exchanger 7, which have a conventional configuration. In addition to the bathtub water circuit 8, the bathtub 9, the heat collector 10, the refrigerant circuit open / close valves 11a, 11b, and 11c, and the bathtub water pump 12, the bathtub water circuit 8 in the bath heat exchanger 7 is branched and connected to the outlet portion. The bypass circuit 13, the bypass circuit on-off valve 14, and the control means 15 are provided. The control means 15 is a control means for opening and closing the bypass circuit on-off valve 14 based on the operation time.
[0016]
Next, the operation and action will be described. When heating the hot water supply using the temperature of the bathtub water in the bathtub 9, the same operation as in the conventional example is performed, the bypass circuit on-off valve 14 is closed at the start of operation, and the bypass circuit 13 has a bathtub water. Do not flush. As the heating operation of the hot water is continued using the temperature of the bath water, a temperature distribution as shown in FIG.
[0017]
At this time, the bypass circuit opening / closing valve 14 is opened from the closed state by the control means 15, and the bypass circuit 13 branched from the bathtub water circuit 8 in the bath heat exchanger 7 and connected to the outlet portion is opened. Accordingly, a part of the bath water flows through the bypass circuit 13 and the pressure loss of the bath water circuit 8 is further reduced, so that the total circulation flow rate of the bath water conveyed by the bath water pump 12 is increased. If the flow rate of the bathtub water circulating in the bathtub water circuit 8 is increased, the convection of the bathtub water in the bathtub 9 is promoted, and the low-temperature bathtub water at the bottom of the bathtub 9 is effectively combined with the bathtub water having a high surface layer temperature. It is stirred by convection.
[0018]
Accordingly, the temperature distribution in the bathtub 9 becomes gradually uniform. When the temperature distribution becomes nearly uniform, the control circuit 15 causes the bypass circuit on-off valve 14 to change from open to closed. The temperature change of the circulating bath water when repeating this operation is shown in FIG. By repeatedly controlling the bypass circuit on / off valve 14, the temperature of the entire bathtub water in the bathtub 9 gradually decreases, and if the system can be operated until it reaches a predetermined temperature or lower, the bathtub water in the bathtub 9 is obtained. It was possible to effectively use the heat of water for heating hot water. Control of the control means 15 causes a part of the bath water to pass through the bypass circuit 13, so that the heat exchange capacity of the bath heat exchanger 7 decreases, but the bath water temperature that returns to the bath 9 rises. The temperature distribution is easy to be made uniform.
[0019]
In the present embodiment, the time a during which the bypass circuit opening / closing valve 14 is closed by the control means 15 is the time until the temperature distribution as shown in FIG. 12 is formed, and the bypass circuit opening / closing valve 14 is opened by the control means 15. A certain time b was set to a value required for the temperature difference between the upper layer portion and the lower layer portion of the bath water to reach a predetermined temperature difference.
[0020]
In this embodiment, one bypass circuit is installed, but a plurality of circuits may be installed. Moreover, you may connect the bathtub water circuit branched to the entrance part instead of the exit part of a bath heat exchanger.
[0021]
Moreover, in a present Example, it can apply also when heating bathtub water. That is, it becomes possible to heat the bathtub water of the bathtub 9 uniformly. Therefore, a highly efficient bathtub heating operation can be performed.
[0022]
(Example 2)
FIG. 3 schematically shows the configuration of a heat pump bath water heater in Embodiment 2 of the present invention. In addition to the conventional configuration, the heat pump bath water heater of the present embodiment has a bypass circuit 13, a bypass circuit on-off valve 14, and a bypass circuit 13 branched from the bathtub water circuit 8 in the bath heat exchanger 7 and connected to the outlet. A temperature sensor 16 and control means 17 are provided.
[0023]
The temperature sensor 16 is a means for detecting the bath water temperature of the bath water circuit 8. The control means 17 is a control means for opening and closing the bypass circuit on-off valve 14 based on the temperature detected by the temperature sensor 16. In this embodiment, a thermistor is used as the temperature sensor 16, but a thermocouple, a resistance temperature detector, or the like may be used. Moreover, the installation position is the bathtub water circuit 8, and the place may be anywhere as long as the bathtub water temperature can be measured.
[0024]
Next, the operation and action will be described. When heating the hot water supply using the temperature of the bathtub water in the bathtub 9, the same operation as in the conventional example is performed, the bypass circuit on-off valve 14 is closed at the start of operation, and the bypass circuit 13 has a bathtub water. Do not flush. As the heating operation of the hot water is continued using the temperature of the bath water, a temperature distribution as shown in FIG. At this time, when the temperature of the temperature sensor 16 becomes equal to or lower than the predetermined temperature T1, the bypass circuit opening / closing valve 14 is opened from the closed state by the control means 17, and the bathtub water circuit 8 in the bath heat exchanger 7 is branched to the outlet portion. The connected bypass circuit 13 is opened.
[0025]
Accordingly, a part of the bathtub water flows from the bathtub outlet 8a through the bypass circuit 13 to the bathtub inlet 8b, and further, the pressure loss of the bathtub water circuit 8 is reduced. The total circulation flow of the tub water increases. If the flow rate of the bathtub water circulating in the bathtub water circuit 8 is increased, the convection of the bathtub water in the bathtub 9 is promoted, and the low-temperature bathtub water at the bottom of the bathtub 9 is effectively combined with the bathtub water having a high surface layer temperature. It is stirred by convection. Accordingly, the temperature distribution in the bathtub 9 becomes gradually uniform.
[0026]
As the temperature distribution becomes uniform, the temperature of the circulating bath water becomes higher. Therefore, when the temperature detected by the temperature sensor 16 exceeds the predetermined temperature T2, the temperature distribution of the bath water in the bath 9 becomes uniform. Judgment is made and the bypass circuit opening / closing valve 14 is changed from open to closed by the control means 17. FIG. 4 shows the temperature change of the circulating bath water when the above operation is repeated.
[0027]
By repeatedly controlling the bypass circuit on / off valve 14, the temperature of the entire bathtub water in the bathtub 9 gradually decreases, and if the system can be operated until it reaches a predetermined temperature or lower, the bathtub water in the bathtub 9 is obtained. It was possible to effectively use the heat of water for heating hot water. Control of the control means 16 causes a part of the bath water to pass through the bypass circuit 13, so that the heat exchanging capacity of the bath heat exchanger 7 is lowered, but the bath water temperature returning to the bath 9 is increased. The temperature distribution is easy to be made uniform.
[0028]
In the present embodiment, the predetermined temperatures T1 and T2 are constant values, but may be specified as a function of the number of repetitions or the operation time, and the same effect can be obtained.
[0029]
In addition, if the existing temperature sensor is installed in order to detect the bath water temperature of the bathtub 9, a present Example can be implemented by utilizing this.
[0030]
Moreover, in a present Example, it can apply also when heating bathtub water. That is, it becomes possible to heat the bathtub water of the bathtub 9 uniformly. Therefore, a highly efficient bathtub heating operation can be performed.
[0031]
(Example 3)
FIG. 5 schematically shows the configuration of a heat pump bath water heater in Embodiment 3 of the present invention. In addition to the conventional configuration, the heat pump bath water heater of this embodiment has a bypass circuit 13, a bypass circuit on-off valve 14, and a pressure branching from the bathtub water circuit in the bath heat exchanger 7 and connected to the outlet portion. A sensor 18 and a control means 19 are provided. The pressure sensor 18 is a differential pressure detection means between the bath water inlet pressure and the outlet pressure of the bath heat exchanger 7.
[0032]
The control means 19 is a control means for opening and closing the bypass circuit on-off valve 14 based on the pressure detected by the pressure sensor 18. In the present embodiment, the pressure sensor 18 is installed as a differential pressure gauge of the bath heat exchanger 7, but may be an absolute pressure or gauge pressure at the inlet or outlet of the bath water of the bath heat exchanger.
[0033]
Next, the operation and action will be described. When the hot water of the bathtub 9 is used to heat the hot water supply, the same operation as in the conventional example is performed, but the bypass circuit on-off valve 14 is closed and the bathtub water is not passed through the bypass circuit 13. . As the heating operation of the hot water is continued using the temperature of the bath water, a temperature distribution as shown in FIG. When the temperature of the bath water flowing into the bath heat exchanger 7 decreases, the viscosity of the bath water increases and the pressure loss of the bath water in the bath heat exchanger 7 increases.
[0034]
That is, the temperature of the circulating bath water is reflected in the detected pressure of the pressure sensor 18. Accordingly, when the differential pressure of the pressure sensor 18 becomes equal to or greater than the predetermined value P1, the control circuit 19 opens the bypass circuit on-off valve 14 from the closed state, branches the bathtub water circuit in the bath heat exchanger 7, and The connected bypass circuit 13 is opened. Accordingly, a part of the bath water flows through the bypass circuit 13, and further, the pressure loss of the bath water circuit 8 decreases, so that the total circulation flow of the bath water conveyed by the bath water pump 8 increases.
[0035]
If the flow rate of the bathtub water circulating in the bathtub water circuit 8 is increased, the convection of the bathtub water in the bathtub 9 is promoted, and the low-temperature bathtub water at the bottom of the bathtub 9 is effectively combined with the bathtub water having a high surface layer temperature. It is stirred by convection. Accordingly, the temperature distribution in the bathtub 9 becomes gradually uniform. When the temperature of the circulating bath water increases, the viscosity of the bath water decreases, and the pressure loss of the bath water in the bath heat exchanger 7 decreases.
[0036]
When the differential pressure detected by the pressure sensor 18 becomes equal to or less than the predetermined value P1, it is determined that the temperature distribution of the bathtub water in the bathtub 9 has become uniform, and the bypass circuit opening / closing valve 14 is changed from open to closed by the control means 19. To do. FIG. 6 shows the temperature change of the circulating bath water when the above operation is repeated. By repeatedly controlling the bypass circuit on / off valve 14, the temperature of the entire bathtub water in the bathtub 9 gradually decreases, and if the system can be operated until it reaches a predetermined temperature or lower, the bathtub water in the bathtub 9 is obtained. It was possible to effectively use the heat of water for heating hot water. Since the heat exchange capacity of the bath heat exchanger 7 is reduced by passing a part of the bath water through the bypass circuit 13 under the control of the control means 17, the bath water temperature returning to the bath 9 rises. The temperature distribution is easy to be made uniform.
[0037]
In the present embodiment, the predetermined pressures P1 and P2 are constant values, but may be specified as a function of the number of repetitions or the operation time, and the same effect can be obtained.
[0038]
Moreover, in a present Example, it can apply also when heating bathtub water. That is, it becomes possible to heat the bathtub water of the bathtub 9 uniformly. Therefore, a highly efficient bathtub heating operation can be performed.
[0039]
(Example 4)
FIG. 7 schematically shows the configuration of a heat pump bath water heater in Embodiment 4 of the present invention. In addition to the conventional configuration, the heat pump bath water heater of this embodiment has a bypass circuit 13, a bypass circuit on-off valve 14, and a temperature branching the bathtub water circuit in the bath heat exchanger 7 and connecting it to the outlet. The sensor 20 and the control means 21 are provided. The temperature sensor 20 is a means for detecting the refrigerant inlet temperature of the bath heat exchanger 7.
[0040]
The control means 21 is a control means for opening and closing the bypass circuit on-off valve 14 based on the temperature detected by the temperature sensor 20. In this embodiment, a thermistor is used for the temperature sensor 20, but a thermocouple, a resistance temperature detector, or the like may be used. Further, the installation position may be the refrigerant outlet of the bath heat exchanger.
[0041]
Next, the operation and action will be described. When the hot water of the bathtub 9 is used to heat the hot water supply, the same operation as in the conventional example is performed, but the bypass circuit on-off valve 14 is closed and the bathtub water is not passed through the bypass circuit 13. . As the heating operation of the hot water is continued using the temperature of the bath water, a temperature distribution as shown in FIG. When the bath water temperature flowing into the bath heat exchanger 7 decreases, the evaporation pressure of the heat pump circuit decreases, so the temperature of the refrigerant flowing into the bath heat exchanger 7 also decreases. That is, the temperature of the circulating bath water is reflected in the temperature detected by the temperature sensor 20.
[0042]
Accordingly, when the temperature of the temperature sensor 20 becomes equal to or lower than the predetermined temperature T3, the bypass circuit on / off valve 14 is opened from the closed state by the control means 21, and the bathtub water circuit in the bath heat exchanger 7 is branched and connected to the outlet. The bypass circuit 13 is opened. Accordingly, a part of the bath water flows through the bypass circuit 13, and further, the pressure loss of the bath water circuit 8 decreases, so that the total circulation flow of the bath water conveyed by the bath water pump 8 increases.
[0043]
If the flow rate of the bathtub water circulating in the bathtub water circuit 8 is increased, the convection of the bathtub water in the bathtub 9 is promoted, and the low-temperature bathtub water at the bottom of the bathtub 9 is effectively combined with the bathtub water having a high surface layer temperature. It is stirred by convection. Accordingly, the temperature distribution in the bathtub 9 becomes gradually uniform. As the temperature distribution becomes uniform, the temperature of the circulating bath water becomes higher. Therefore, when the temperature detected by the temperature sensor 20 becomes equal to or higher than the predetermined temperature T4, the temperature distribution of the bath water in the bath 9 becomes uniform. Judgment is made and the bypass circuit opening / closing valve 14 is changed from open to closed by the control means 21.
[0044]
FIG. 8 shows the temperature change of the circulating bath water when the above operation is repeated. By repeatedly controlling the bypass circuit on / off valve 14, the temperature of the entire bathtub water in the bathtub 9 gradually decreases, and if the system can be operated until it reaches a predetermined temperature or lower, the bathtub water in the bathtub 9 is obtained. It was possible to effectively use the heat of water for heating hot water. Control of the control means 21 causes a part of the bath water to pass through the bypass circuit 13, so that the heat exchange capacity of the bath heat exchanger 7 decreases, but the bath water temperature that returns to the bath 9 rises. The temperature distribution is easy to be made uniform.
[0045]
In addition, in order to control a heat pump cycle, if a temperature sensor is installed in the refrigerant | coolant inlet of a bathtub water heat exchanger, or an exit, a present Example can be implemented using this. On the contrary, when not installed, the heat pump cycle can be controlled using the temperature sensor installed in the present embodiment.
[0046]
In the present embodiment, the predetermined temperatures T3 and T4 are constant values, but may be specified as a function of the number of repetitions or the operation time, and the same effect can be obtained.
[0047]
Moreover, in a present Example, it can apply also when heating bathtub water. That is, it becomes possible to heat the bathtub water of the bathtub 9 uniformly. Therefore, a highly efficient bathtub heating operation can be performed.
[0048]
(Example 5)
FIG. 9 schematically shows the configuration of a heat pump bath water heater in Embodiment 5 of the present invention. In addition to the conventional configuration, the heat pump bath water heater of this embodiment has a bypass circuit 13, a bypass circuit on-off valve 14, and a pressure branching from the bathtub water circuit in the bath heat exchanger 7 and connected to the outlet portion. The sensor 22 and the control means 23 are provided. The pressure sensor 22 is a means for detecting the refrigerant inlet pressure of the bath heat exchanger 7. The control means 23 is a control means for opening and closing the bypass circuit on-off valve 14 based on the pressure detected by the pressure sensor 22. In this embodiment, the pressure sensor 22 is installed at the refrigerant inlet of the bath heat exchanger 7, but the installation position may be the refrigerant outlet of the bath heat exchanger.
[0049]
Next, the operation and action will be described. When the hot water of the bathtub 9 is used to heat the hot water supply, the same operation as in the conventional example is performed, but the bypass circuit on-off valve 14 is closed and the bathtub water is not passed through the bypass circuit 13. . As the heating operation of the hot water is continued using the temperature of the bath water, a temperature distribution as shown in FIG. When the bath water temperature flowing into the bath heat exchanger 7 decreases, the pressure at which the refrigerant in the heat pump circuit evaporates decreases. That is, the temperature of the circulating bath water is reflected in the detected pressure of the pressure sensor 22.
[0050]
Therefore, when the detected pressure of the pressure sensor 22 becomes equal to or lower than the predetermined value P3, the bypass circuit opening / closing valve 14 is opened from the closed state by the control means 23, the bathtub water circuit in the bath heat exchanger 7 is branched, The connected bypass circuit 13 is opened. Accordingly, a part of the bath water flows through the bypass circuit 13 and the pressure loss of the bath water circuit 8 is further reduced, so that the total circulation flow rate of the bath water conveyed by the bath water pump 12 is increased. If the flow rate of the bathtub water circulating in the bathtub water circuit 8 is increased, the convection of the bathtub water in the bathtub 9 is promoted, and the low-temperature bathtub water at the bottom of the bathtub 9 is effectively combined with the bathtub water having a high surface layer temperature. It is stirred by convection. Accordingly, the temperature distribution in the bathtub 9 becomes gradually uniform.
[0051]
As the temperature distribution becomes uniform, the temperature of the circulating bath water becomes higher. Therefore, when the detected pressure of the pressure sensor 22 becomes equal to or higher than the predetermined value P4, the temperature distribution of the bath water in the bath 9 becomes uniform. Judgment is made and the bypass circuit opening / closing valve 14 is changed from open to closed by the control means 23. FIG. 10 shows the temperature change of the circulating bath water when the above operation is repeated.
[0052]
By repeatedly controlling the bypass circuit on / off valve 14, the temperature of the entire bathtub water in the bathtub 9 gradually decreases, and if the system can be operated until it reaches a predetermined temperature or lower, the bathtub water in the bathtub 9 is obtained. It was possible to effectively use the heat of water for heating hot water. Control of the control means 23 causes a part of the bath water to pass through the bypass circuit 13, so that the heat exchange capacity of the bath heat exchanger 7 decreases, but the bath water temperature that returns to the bath 9 rises. The temperature distribution is easy to be made uniform.
[0053]
In addition, in order to control a heat pump cycle, if a pressure sensor is installed in the refrigerant | coolant inlet of a bathtub water heat exchanger, or an exit, a present Example can be implemented using this. On the contrary, when not installed, the heat pump cycle can be controlled using the pressure sensor installed in the present embodiment.
[0054]
In the present embodiment, the predetermined pressures P3 and P4 are constant values, but may be specified as a function of the number of repetitions or the operation time, and the same effect can be obtained.
[0055]
Moreover, in a present Example, it can apply also when heating bathtub water. That is, it becomes possible to heat the bathtub water of the bathtub 9 uniformly. Therefore, a highly efficient bathtub heating operation can be performed.
[0056]
According to the heat pump bath water heater described in the above embodiment, the following effects can be obtained.
[0057]
(1) When performing hot water heating operation using the temperature of the bath water, even if a bath water temperature distribution that is disadvantageous in operating efficiency is formed in the depth direction of the bath, the bath water flows through the bypass circuit. Thus, the temperature distribution of the bathtub can be made uniform.
[0058]
Therefore, since the temperature of the bathtub water can be effectively used for heating the hot water supply, high efficiency can be achieved when the hot water heating operation is performed using the temperature of the bathtub water.
[0059]
(2) When the bypass circuit is opened, the circulating flow rate increases, so that dirt is less likely to adhere to the bathtub, the bathtub water circuit, and the bath heat exchanger.
[0060]
(3) Even if clogging occurs due to dirt or corrosion in the bath water at the outlet of the bath heat exchanger, it is possible to exchange heat with the bath water in the bath heat exchanger by using the bypass circuit. Life extension is possible.
[0061]
(4) Since the added temperature sensor can be used as a means to sense the safety of the device, the safety of the device is improved, and this temperature sensor is also used to control the temperature of the bath water. You can also.
[0062]
(5) When the bath heat exchanger becomes dirty and the pressure loss in the bath water flow path increases, this state can be detected by the pressure sensor. Therefore, it is possible to provide a function for notifying the maintenance time.
[0063]
(6) Since the temperature sensor can be used for heat pump cycle control, the use of this temperature sensor can increase the efficiency of the apparatus.
[0064]
【The invention's effect】
As described above, according to the heat pump bath water heater of the present invention, the temperature of the bath water can be effectively used for heating the hot water supply, and an improvement in efficiency can be expected.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating the configuration of a heat pump bath water heater in Embodiment 1 of the present invention. FIG. 2 is a diagram showing the relationship between the operation time of the heat pump bath water heater and the bath water temperature. FIG. 4 is a diagram illustrating the configuration of the heat pump bath water heater in Example 2. FIG. 5 is a diagram showing the relationship between the operation time of the heat pump bath water heater and the bath water temperature. FIG. FIG. 6 is a diagram illustrating the relationship between the operation time of the heat pump bath water heater and the bath water temperature. FIG. 7 is a diagram illustrating the configuration of the heat pump bath water heater in Embodiment 4 of the present invention. FIG. 9 is a diagram illustrating the relationship between the operation time of the heat pump bath water heater and the bath water temperature. FIG. 9 is a diagram illustrating the configuration of the heat pump bath water heater in Embodiment 5 of the present invention. Fig. 11 is a diagram illustrating the relationship between the bath temperature and the bath water temperature. Fig. 11 is a diagram illustrating the configuration of a conventional heat pump bath water heater. Fig. 12 is a diagram illustrating the relationship between the bath water depth and the bath water temperature of the heat pump bath water heater. Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Compressor 2a, 2b Expansion valve 3 Refrigerant circuit 4 Hot water supply heat exchanger 5 Hot water supply circuit 6 Hot water storage tank 7 Bath heat exchanger 8 Bath water circuit 9 Bath 10 Heat collector 11a, 11b, 11c Open / close valve 12 Bath water pump 13 Bypass Circuit 14 Bypass circuit on / off valve 15 Control means for controlling bypass circuit on / off valve based on operating time 16, 20 Temperature sensor 17, 21 Control means for controlling bypass circuit on / off valve based on temperature detected by temperature sensor 18, 22 Pressure Sensors 19, 23 Control means for controlling the bypass circuit on-off valve based on the pressure detected by the pressure sensor

Claims (5)

A heat pump circuit having a compressor, a bathtub, a hot water supply circuit having a hot water heat exchanger for exchanging heat between the refrigerant of the heat pump circuit and hot water, and a bathtub water pump and the heat pump circuit for recovering the heat of the bathtub water A bath water circuit having a bath heat exchanger, a bypass circuit branched from the middle of the bath heat exchanger and connected to a bath water outlet of the bath heat exchanger, and the bypass circuit a bypass circuit switch valve for opening and closing, in conjunction with the upper and lower temperature difference between the bath water within the bath and control means for controlling the bypass circuit switch valve, the upper and lower temperature difference of the bath water in the bathtub is higher than a predetermined value when it becomes a part of the middle of the bath water, which is endothermic in the bath heat exchanger by the action of the bath water pump causes it flows through the bypass circuit, and flows all the bath heat exchanger Circulate in the circulatory system together with the rest of the bathtub water, thereby suppressing the decrease in the temperature of the bathtub water returning to the bathtub and increasing the total circulation amount of the bathtub water returning to the bathtub by a short circulation path via the bypass circuit. A heat pump bath water heater characterized by stirring the bathtub water in the bathtub and reducing the temperature difference between the top and bottom .   The heat pump bath water heater according to claim 1, wherein the difference in temperature between the upper and lower sides of the bathtub water in the bathtub is estimated by the operation time.   The heat pump bath water heater according to claim 1, wherein the temperature difference between the upper and lower sides of the bathtub water in the bathtub is detected based on the temperature of the bathtub water in the bathtub water circuit.   The heat pump bath water heater according to claim 1, wherein the temperature difference between the upper and lower sides of the bathtub water in the bathtub is detected based on the pressure of the bathtub water flowing through the bath heat exchanger.   The heat pump bath water heater according to claim 1, wherein the temperature difference between the upper and lower water in the bathtub is detected based on the temperature or pressure of the refrigerant flowing in the bath heat exchanger.

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