JP6134910B2 - Heat pump water heater - Google Patents

Description

  The present invention relates to a heat pump water heater.

Conventionally, this type of heat pump hot-water supply apparatus has a thing like FIG. 22 , for example (for example, refer patent document 1).

FIG. 22 shows a conventional heat pump hot-water supply device described in Patent Document 1. In FIG.

As shown in FIG. 22 , a compressor 104, a water-refrigerant heat exchanger 105, a decompression means 106, and an air heat exchanger (evaporator) 107 are connected in a tubular shape by a refrigerant pipe to form a heat pump cycle.

  The bottom of the hot water storage tank 103, the pump 119, and the water / refrigerant heat exchanger 105 are sequentially connected by an HP pipe 118. Further, the outlet hot water temperature of the water-refrigerant heat exchanger 105 (hereinafter referred to as hot water temperature) is detected by a hot water temperature sensor 121 installed in the middle of the HP pipe 118.

  In the hot water storage operation mode, water at the bottom of the hot water storage tank 103 is transferred to the water / refrigerant heat exchanger 105 by the pump 119, where it is heated to become hot water by heat exchange with the refrigerant in the heat pump cycle, and the HP pipe 118, hot water supply It returns to the upper part of the hot water storage tank 103 via the pipe 120.

  At this time, the hot water temperature, the rotation speed of the pump 119, and the operation control of each component of the heat pump cycle are performed by the control device 125.

  A hot water discharge pipe 120 is connected to the top of the hot water storage tank 103, and a water supply pipe 109 is connected to the bottom of the hot water storage tank 103.

  The hot water mixing valve 111 mixes the hot water in the upper part of the hot water storage tank supplied from the hot water supply pipe 120 and the water supplied from the water supply pipe 109 to supply hot water at a predetermined temperature from the hot water supply terminal 114 via the hot water supply pipe 113. Let The hot water temperature at the outlet of the hot water supply mixing valve 111 is detected by a hot water supply temperature sensor 122 installed in the middle of the hot water supply pipe 113.

  The hot water mixing valve 112 mixes the hot water in the upper part of the hot water storage tank supplied from the hot water pipe 120 and the water supplied from the water supply pipe 109 to supply hot water at a predetermined temperature to the hot water pipe 115 and the hot water on / off valve 116. Hot water is supplied to the bathtub 117 via

  The hot water temperature at the outlet of the hot water mixing valve 112 is detected by a hot water temperature sensor 123 installed in the middle of the hot water pipe 115. Further, the water level of the bathtub 117 is detected by a hot water pressure sensor 129 installed in the hot water pipe 115.

  In addition, the hot water operation to the bathtub 117 has a hot water operation mode, and at the start of the hot water operation mode, the heat pump cycle is started, the hot water on / off valve 116 is opened, and the HP pipe 118 is connected. The hot water passed through and the hot water from the hot water storage tank 103 join together in the hot water discharge pipe 120, and are supplied to the bathtub 117 through the hot water mixing valve 112 and the hot water pipe 115.

  In addition, the coefficient of performance of the heat pump cycle (hereinafter referred to as COP) is reduced by reducing the temperature of the hot water in the hot water operation mode to the temperature of the hot water in the hot water operation mode and lowering the heating capacity. Since the COP is improved over time, an efficient hot water operation can be performed.

Japanese Patent No. 4975067

  However, in the conventional configuration, since the hot water stored in the hot water storage tank and the hot water heated in the heat pump cycle are used in combination in the hot water operation mode, the amount of hot water used in the hot water storage tank fluctuates. The problem was that excess and deficiency would occur in the amount of hot water held in Japan.

  This invention solves the said conventional subject, and it aims at providing the heat pump hot-water supply apparatus excellent in energy-saving property by suppressing the excess and deficiency of the hot water amount stored in a hot water storage tank.

In order to solve the above-described conventional problems, a heat pump hot water supply apparatus of the present invention includes a heat pump cycle in which a compressor, a water refrigerant heat exchanger, a decompression unit, and an evaporator are connected by refrigerant piping, and hot water generated by heating with the heat pump cycle. A hot water storage tank for storing hot water, a pipe for returning hot water generated by heating in the heat pump cycle to the upper part of the hot water storage tank, a first outlet pipe for taking out hot water from the upper part of the hot water storage tank, and hot water stored in the hot water storage tank Hot water storage temperature detecting means for detecting the temperature of the hot water, and control means for executing at least a plurality of operation modes, wherein the plurality of operation modes store hot water generated by the heat pump cycle in the hot water storage tank. And hot water having a temperature lower than that of the hot water storage operation mode by the heat pump cycle, The hot water produced heated by chromatography preparative pump cycle, via a pipe for returning to the upper portion of the hot water storage tank, once, after being introduced into the hot water storage tank, the
A hot water operation mode used for pouring into the bathtub via the first hot water discharge pipe, and the coefficient of performance of the heat pump cycle in the hot water operation mode is from the coefficient of performance of the heat pump cycle in the hot water storage operation mode And the control means shifts to the hot water storage operation mode when the detected temperature of the hot water storage temperature detection means is lower than a first predetermined value when the hot water beam operation mode is completed. To do.

  Thereby, based on the hot water storage temperature, it is possible to determine whether or not to execute the hot water storage operation mode after the hot water beam operation mode is completed so as not to cause excess or shortage of hot water in the hot water storage tank.

  ADVANTAGE OF THE INVENTION According to this invention, the heat pump hot-water supply apparatus excellent in energy saving property can be provided, suppressing the excess and deficiency of the hot water in a hot water storage tank.

The block diagram of the heat pump hot-water supply apparatus in Embodiment 1 of this invention The figure which shows the change of the temperature distribution in the hot water storage tank of the heat pump water heater Control flow chart at the start of hot water operation mode of the heat pump water heater Other control flowchart at the start of hot water operation mode of the heat pump water heater Explanatory drawing which shows the example of the threshold value of the comparison judgment at the time of judging the start of a heat pump cycle in the hot water operation mode of the heat pump hot water supply apparatus Still another control flowchart at the start of the hot water operation mode of the heat pump water heater Explanatory drawing which shows the example of the threshold value of the other comparative judgment at the time of judging the starting of a heat pump cycle in the hot water operation mode of the heat pump hot water supply apparatus The graph which shows the operation | movement sequence of the hot water operation mode of the heat pump water heater The graph which shows the relationship between COP of a heat pump cycle and tapping temperature in the same heat pump water heater The graph which shows the relationship between the heating capacity and compression ratio of the heat pump cycle in the heat pump water heater The graph which shows the relationship between the heating capability of the heat pump cycle and the COP of the heat pump cycle in the hot water beam operation mode of the heat pump water heater The graph which shows the relationship between the heating capability of the heat pump cycle in the hot water operation mode of the same heat pump water heater, and the bath pouring COP The graph which shows the relationship between the compressor rotation speed and bath pouring COP in the hot water operation mode of the heat pump water heater Control flow chart at the end of the hot water operation mode of the heat pump water heater Another control flowchart at the completion of the hot water operation mode of the heat pump water heater Explanatory drawing which shows the example of the threshold value of the comparison judgment at the time of judging the transfer of the operation mode at the time of completion of the hot water operation mode of the heat pump water heater Still another control flowchart at the completion of the hot water operation mode of the heat pump water heater Explanatory drawing which shows the example of the threshold value of the comparison judgment at the time of judging the transfer of the operation mode at the time of completion of the hot water operation mode of the heat pump water heater (A) The figure which showed the change of the temperature distribution in a hot water storage tank when there is a middle temperature hot water supply circuit of a heat pump hot water supply device, (b) The change of the temperature distribution in the hot water storage tank when there is no intermediate temperature hot water supply circuit of a heat pump hot water supply device Illustration shown The block diagram of the heat pump hot-water supply apparatus in Embodiment 2 of this invention The block diagram of the heat pump hot-water supply apparatus in Embodiment 3 of this invention Configuration diagram of conventional heat pump water heater

A first invention is a heat pump cycle in which a compressor, a water refrigerant heat exchanger, a decompression means, and an evaporator are connected by refrigerant piping, a hot water storage tank for storing hot water heated and generated by the heat pump cycle, and heating by the heat pump cycle A pipe for returning the generated hot water to the upper part of the hot water storage tank, a first hot water discharge pipe for taking out hot water from the upper part of the hot water storage tank, hot water storage temperature detecting means for detecting the temperature of the hot water stored in the hot water storage tank, Control means for executing a plurality of operation modes, wherein the plurality of operation modes are different from the hot water storage operation mode in which the hot water heated and generated by the heat pump cycle is stored in the hot water storage tank and the hot water storage operation mode by the heat pump cycle. Hot water produced by the heat pump cycle while producing hot water at a lower temperature. , Via a pipe for returning to the upper portion of the hot water storage tank, once, after flowing into the hot water storage tank via the first tapping pipe, a hot water beam operating mode used for pouring into the bathtub, And the coefficient of performance of the heat pump cycle in the hot water operation mode is higher than the coefficient of performance of the heat pump cycle in the hot water storage operation mode, and the control means is the hot water storage temperature detection means when the hot water operation mode is completed When the detected temperature is lower than a first predetermined value, the heat pump hot water supply device is shifted to the hot water storage operation mode.

  This makes it possible to determine whether or not to enter the hot water storage operation mode after the hot water operation mode ends based on the hot water storage temperature, so that the boiling temperature of the heat pump cycle is made lower than the hot water storage temperature to improve COP. In addition, excessive or insufficient hot water in the hot water storage tank can be suppressed.

  In addition, since the heat pump cycle is transferred without stopping the operation of the heat pump cycle from the hot water operation mode performed by starting the heat pump cycle, the energy loss is reduced and the energy consumption efficiency of the heat pump water heater is improved. Can do.

  According to a second aspect of the invention, particularly in the first aspect of the invention, a hot water supply flow rate detecting means for detecting a hot water supply flow rate of hot water supplied to the hot water supply terminal and the bathtub, and a hot water supply temperature of hot water supplied to the hot water supply terminal and the bathtub are detected. Hot water supply temperature detection means, and the control means includes hot water supply heat amount calculation means for calculating and storing an accumulated hot water supply heat amount per day from the hot water supply flow rate and the hot water supply temperature, and the control means includes When the accumulated hot water supply heat quantity is larger than a second predetermined value and the detected temperature of the hot water storage temperature detecting means is lower than the first predetermined value when the hot water operation mode is completed, the process shifts to the hot water storage operation mode. It is characterized by doing.

  This makes it possible to predict whether or not to enter the hot water storage operation mode by predicting the amount of hot water used after hot water supply based on the accumulated amount of hot water supply for each day, thereby suppressing excess or shortage of hot water in the hot water storage tank. And the heat pump hot-water supply apparatus excellent in energy saving property can be provided.

  According to a third aspect of the present invention, particularly in the second aspect of the invention, the apparatus further comprises a bath reheating circuit having a bath heat exchanger for exchanging heat between the hot water in the hot water storage tank and the hot water in the bathtub, and the control means includes the bath reheating circuit. Reheating calorific value calculating means for calculating the heat retaining heat amount of the hot water used in the hot water storage tank and storing it as the accumulated heat retaining heat amount per day, and the control means in the hot water operation mode, And the accumulated heat retention heat amount is larger than the second predetermined value, and the detected temperature of the hot water storage temperature detecting means is lower than the first predetermined value when the hot water operation mode is completed, It shifts to the said hot water storage operation mode, It is characterized by the above-mentioned.

Thereby, based on the accumulated heat retention heat amount every day, the amount of hot water supply after bath hot water is predicted,
Since it can be determined whether or not to shift to the hot water storage operation mode, it is possible to provide a heat pump hot water supply apparatus that is excellent in energy saving by suppressing excessive or insufficient hot water in the hot water storage tank.

A fourth invention is, in particular, the first to third any one of the, obtain Preparations medium temperature hot water pipe to take out hot water from the hot water storage tank below the piping and the first tapping pipe back to the upper portion of the hot water storage tank It is characterized by this.

  Thereby, the hot water heated and generated in the heat pump cycle in the hot water operation mode once flows into the hot water storage tank. Therefore, even if it is in the state which cannot heat water immediately after starting of a heat pump cycle, the hot water which flows out from a 1st tapping pipe and is poured is maintained above predetermined temperature. Therefore, hot water having a predetermined temperature or more can be poured immediately after the start of the heat pump cycle in the hot water operation mode. Further, in the hot water operation mode, hot water having a temperature lower than that of hot water in the hot water storage tank flows from the upper part of the hot water storage tank, and even if medium hot water is generated, the hot water hot water pipe connected below the first hot water discharge pipe. Therefore, it is possible to suppress the diffusion of the intermediate temperature water to the bottom of the hot water storage tank and maintain the heating efficiency of the heat pump cycle high.

  The fifth invention is characterized in that, in any one of the first to fourth inventions, the heat pump cycle operates in a state where the pressure on the high pressure side exceeds the critical pressure of the refrigerant.

  Thereby, since COP when heating water by heat pump cycle and producing hot water can be made high, in both the hot water storage operation mode and the hot water operation mode, the heating efficiency of the heat pump cycle is improved, As a result, the energy saving property of the heat pump water heater can be improved.

  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 diagram showing a configuration of a heat pump hot water supply apparatus according to the first embodiment of the present invention. The heat pump hot water supply apparatus includes a heat pump unit 2a and a hot water storage unit 2b.

  The heat pump unit 2a is provided with a heat pump cycle 1 in which a compressor 4, a water-refrigerant heat exchanger 5, a decompression means 6 such as an expansion valve, and an evaporator 7 which is an air heat exchanger are connected in an annular shape with a refrigerant pipe. A refrigerant is sealed inside the refrigerant pipe. A fan 8 supplies air to the evaporator 7. Carbon dioxide or HFC refrigerant can be used as the refrigerant. When carbon dioxide is used as the refrigerant, the pressure on the high pressure side of the heat pump cycle exceeds the critical pressure of the refrigerant, and the heat pump cycle operates in a supercritical state.

  The hot water storage unit 2b is provided with a boiling circuit in which the bottom of the hot water storage tank 3, the boiling forward piping 32, the water refrigerant heat exchanger 5, the boiling return piping 33, the four-way switching valve 18a, and the hot water storage tank 3 are connected in an annular shape. ing.

  A boiling pump 21 that conveys the water at the bottom of the hot water storage tank 3 to the water-refrigerant heat exchanger 5 is connected to the middle of the boiling piping 32.

A boiling return pipe 33 is connected to the inlet side of the four-way switching valve 18a. The outlet side of the four-way switching valve 18 a is connected to the bottom of the hot water storage tank 3 by a boiling bypass pipe 34, and the other outlet side of the four-way switching valve 18 a is connected to a substantially top part of the hot water storage tank 3 through a heating pipe 35. The other outlet side of the four-way switching valve 18a is connected to the upper part of the hot water storage tank 3 via a hot water return pipe 36.

  That is, the hot water in the boiling return pipe 33 conveyed by the boiling pump 21 returns to the bottom of the hot water storage tank 3 by the four-way switching valve 18a and the upper part of the hot water storage tank 3 (boiling pipe 35 or hot water). It is possible to switch between returning to the return pipe 36).

  Moreover, the incoming water temperature detection means 41 which is the incoming water temperature sensor which detects the water temperature of the inlet of the water-refrigerant heat exchanger 5, and the outgoing hot water temperature detection means 42 which is the outgoing water temperature sensor which detects the water temperature of the outlet of the water-refrigerant heat exchanger 5. Is provided.

  A plurality of remaining hot water thermistors (temperature sensors) 40a to 40e as hot water storage temperature detecting means are installed on the wall surface of the hot water storage tank 3, and the amount of heat stored in the hot water storage tank 3 is grasped based on the temperature of the remaining hot water thermistors 40a to 40e. can do.

  Water from the water supply is supplied to the hot water storage tank 3, a third mixing valve 14, and a first mixing valve 15, which will be described later, via a water supply pipe 11 to which a pressure reducing valve 20 is connected. The water supply pipe 11 branches into a second water supply branch pipe 12 a, a third water supply branch pipe 12 b, and a first water supply branch pipe 12 c at the water supply branch section 12, and the second water supply branch pipe 12 a is formed at the bottom of the hot water storage tank 3. The third water supply branch pipe 12 b is connected to the third mixing valve 14, and the first water supply branch pipe 12 c is connected to the first mixing valve 15.

  A first hot water discharge pipe 9 is connected to the upper part of the hot water storage tank 3. An intermediate temperature hot water discharge pipe 10 is connected to a position below the position where the first hot water discharge pipe 9 and the hot water return pipe 36 are connected in the vertical direction of the hot water storage tank 3 and above the bottom of the hot water storage tank 3. The other end of the first hot water pipe 9 branches into a hot water branch pipe 16 and a reheating pipe 25, the hot water branch pipe 16 is connected to the second mixing valve 13, and the reheating pipe 25 is connected to the bath heat exchanger 24. Has been.

  The hot water supply circuit mixes the hot water in the hot water storage tank 3 and the water supplied from the water supply with the second mixing valve 13, the third mixing valve 14, and the first mixing valve 15 to obtain hot water at a predetermined temperature. It is a circuit for supplying hot water to a hot water supply terminal (not shown) such as a shower or a bathtub.

  The second mixing valve 13 mixes the hot water supplied from the first hot water discharge pipe 9 and the hot water supplied from the intermediate hot water hot water pipe 10 and causes the hot water to flow out from the hot water joining pipe 17. The outgoing hot water junction pipe 17 branches into a first outgoing hot water joint pipe branch pipe 17a and a second outgoing hot water joint pipe branch pipe 17b. The first outgoing hot water joint pipe branch pipe 17a is connected to the third mixing valve 14 and the second outgoing hot water joint pipe. The branch pipes 17b are connected to the first mixing valve 15, respectively.

  The third mixing valve 14 mixes hot water supplied from the first outlet hot water merging pipe branch pipe 17a and water supplied from the third water supply branch pipe 12b, and causes the hot water to flow out from the hot water pipe 28 to supply hot water such as a currant or shower. Hot water of a predetermined temperature is supplied from a terminal (not shown).

  The hot water supply pipe 28 connected to the outlet side of the third mixing valve 14 is provided with a hot water supply temperature sensor 43a as a first hot water supply temperature detection means. When hot water is supplied from a hot water supply terminal, the hot water supply temperature sensor 43a detects the hot water supply temperature sensor 43a. The control unit 51 controls the mixing ratio of the third mixing valve 14 so that the temperature becomes the target set temperature (set by the user from the remote controller 50).

The first mixing valve 15 mixes the hot water supplied from the second outlet hot water junction branch pipe 17b and the water supplied from the first water supply branch pipe 12c and causes the hot water to flow out from the bath pouring pipe 27. Then, hot water having a predetermined temperature is poured into the bathtub 31 through the bath going-out pipe 29 and the bath return pipe 30.

  The bath pouring pipe 27 connected to the outlet side of the first mixing valve 15 is provided with a bath hot water temperature sensor 43b as a second hot water temperature detecting means. The control unit 51 controls the mixing ratio of the third mixing valve 14 so that the detected temperature of the sensor 43b becomes the target set temperature (set by the user from the remote controller 50).

  Hot water pouring into the bathtub 31 using the first mixing valve 15 can be started by operating the remote controller 50 as setting operation means. For example, it can be started by pressing an automatic bath hot water button provided on the remote controller 50. When bath remote hot water is instructed from the remote controller 50 to the control means 51, the control means 51 opens the pouring valve 19 and pours water into the bathtub 31 through the first mixing valve 15 and the bath pouring pipe 27.

  The hot water supply pipe 28 is provided with a hot water supply flow rate sensor 47a as a first hot water supply flow rate detection means, and the bath pouring pipe 27 is provided with a bath hot water supply flow rate sensor 47b as a second hot water supply flow rate detection means. Can be detected as the hot water supply flow rate. The detected hot water flow rate is sent as a signal to the control means 51 for processing. The hot water supply heat amount calculating means 52 can calculate and store the accumulated hot water supply amount per day using this, and the hot water supply heat amount is combined with the detected temperatures of the hot water temperature sensor 43a and the bath hot water temperature sensor 43b. Can be calculated and stored.

  The bath reheating circuit can heat the hot water in the bathtub 31 to a predetermined temperature by exchanging heat between the hot water in the hot water storage tank 3 and the hot water in the bathtub 31 by the bath heat exchanger 24.

  The bath reheating circuit is configured by connecting the hot water storage tank 3, the first hot water discharge pipe 9, the reheating pipe 25, the bath heat exchanger 24, the reheating pump 22, the reheating return pipe 26, and the hot water storage tank 3 in an annular shape. A primary circuit and a secondary circuit configured by connecting the bathtub 31, the bath return pipe 30, the bath circulation pump 23, the bath heat exchanger 24, the bath outlet pipe 29, and the bathtub 31 in an annular shape are provided. . Further, in the middle of the recirculation return pipe 26, in the middle of the recuperation return temperature sensor 44 for detecting the temperature of hot water returning from the bath heat exchanger 24 to the hot water storage tank 3 via the reheating pump 22, and in the middle of the bath return pipe 30. Are provided with a bath temperature sensor 45 as a bath temperature detecting means for detecting a hot water temperature in the bathtub 31 and a water level sensor 46 as a bathtub water level detecting means. The reheating heat amount calculation means 53 (not shown) keeps the heat amount of the hot water used to heat or reheat the hot water in the bathtub 31 from the reheating return temperature detected by the reheating temperature sensor 44. It can be calculated as the amount of heat, and can be stored as the accumulated heat retaining heat amount for each day.

  Moreover, the heat pump hot water supply apparatus of the present invention activates the heat pump cycle 1 to store the hot water heated in the heat pump cycle 1 in the hot water storage tank 3 and when the hot water is poured into the bathtub 31, and the hot water storage operation mode. And a hot water operation mode in which water is heated and generated at a lower temperature than in the case of heating at

  The control means 51 performs operation control of the heat pump cycle 1 in the hot water storage operation mode and the hot water operation mode. At this time, the control means 51 receives, as signals, the integrated hot water supply heat amount calculated and stored by the hot water supply heat amount calculation means 52 and the integrated heat retention heat amount calculated and stored by the reheating heat amount calculation means 53. Used for control.

  About the heat pump hot water supply apparatus comprised as mentioned above, operation | movement of the operation mode of a heat pump hot water supply apparatus is demonstrated.

  The hot water storage operation mode is a mode in which the water at the bottom of the hot water storage tank 3 is heated by the heat pump cycle 1 and then stored in the upper part of the hot water storage tank 3. It is normal to use cheap electricity at midnight (23:00 to 7:00 the next morning), but if the amount of hot water in the hot water storage tank 3 decreases and the risk of running out of hot water arises, the daytime There is a case of driving from (7 o'clock to 23 o'clock).

  During the hot water storage operation, the refrigerant sealed in the heat pump cycle 1 of the heat pump unit 2a is sucked into the compressor 4 in a low-pressure gas state, compressed into a high-temperature and high-pressure state, and then transferred to the water-refrigerant heat exchanger 5. It exchanges heat with the water transported from the hot water storage tank 3 and becomes itself in a low temperature and high pressure state.

  Thereafter, the refrigerant becomes a gas-liquid two-phase refrigerant expanded to a low-temperature and low-pressure state by the decompression means 6 such as an expansion valve, and the evaporator 7 absorbs heat from the outside air blown by the fan 8 to become a low-pressure gas refrigerant. Repeatedly inhaling.

  On the other hand, the water at the bottom of the hot water storage tank 3 is conveyed to the water / refrigerant heat exchanger 5 via the boiling forward pipe 32 by the boiling pump 21, and is heated by exchanging heat with the refrigerant of the heat pump cycle 1. It becomes warm water. Thereafter, the heated hot water is returned to the top or bottom of the hot water storage tank 3 through the boiling return pipe 33 and the four-way switching valve 18a.

  The temperature of the hot water at the outlet of the water-refrigerant heat exchanger 5 does not reach the target hot water temperature immediately after the heat pump cycle 1 is started, but takes some time. While the temperature detected by the hot water temperature detection means 42 (hereinafter referred to as the detected temperature) is lower than the target hot water temperature (for example, when the temperature difference between the target hot water temperature and the detected temperature is greater than or equal to a predetermined value), boiling is performed. The hot water in the return pipe 33 is returned to the bottom of the hot water storage tank 3 through the boiling bypass pipe 34 by the four-way switching valve 18a.

  Thereafter, when the detected temperature approaches the target hot water temperature (for example, when the temperature difference between the target hot water temperature and the detected temperature becomes less than a predetermined value), the four-way switching valve 18a is switched to warm water in the boiling return pipe 33. Is returned to the upper part of the hot water storage tank 3 through the boiling pipe 35 and the first hot water discharge pipe 9. With the above operation, the hot temperature heated in the heat pump cycle 1 is stored in the hot water storage tank 3.

  Next, the operation of the medium temperature hot water by the second mixing valve 13 in the hot water supply circuit will be described. FIG. 2 shows an example of the temperature distribution in the hot water storage tank 3 after supplying a predetermined amount of hot water from a state where the entire amount of the hot water storage tank 3 is boiled. The solid line in FIG. 2 indicates the case where the medium temperature hot water is performed, and the broken line indicates the case where the medium temperature hot water is not performed.

  When hot water is supplied to the hot water supply terminal or the bathtub 31 at the target hot water supply temperature T1 (° C.) set by the user, hot water supplied from the upper part of the hot water storage tank 3 via the first hot water discharge pipe 9 and the hot water branch pipe 16; Hot water supplied from a substantially central portion of the hot water storage tank 3 via the intermediate hot water discharge pipe 10 is mixed by the second mixing valve 13, and hot water having a temperature higher than the target hot water supply temperature T1 by a predetermined temperature difference δT (K). As shown in FIG.

  When hot water is supplied to the hot water supply terminal at the target hot water supply temperature T1 (° C.), hot water of T1 + δT (° C.) supplied from the second mixing valve 13 via the hot water joining pipe 17 and the first hot water joining pipe branch pipe 17a; The third mixing valve is mixed with the water supplied from the water supply pipe 11 via the second water supply branch pipe 12b by the third mixing valve 14 so that the detected temperature of the hot water supply temperature sensor 43a becomes the target hot water supply temperature T1. 14 is controlled by the control means 51.

When hot water is supplied to the bathtub 31 at the target hot water supply temperature T1 (° C.), the hot water of T1 + δT (° C.) supplied from the second mixing valve 13 via the hot water joining pipe 17 and the second hot water joining pipe branch pipe 17b. And the water supplied from the water supply pipe 11 via the first water supply branch pipe 12c are mixed by the first mixing valve 15 so that the detected temperature of the bath hot water temperature sensor 43b becomes the target hot water temperature T1. The mixing ratio of the 1 mixing valve 15 is controlled by the control means 51.

  In the present embodiment, the temperature sensor is not installed on the outlet side of the second mixing valve 13, and the hot water temperature supplied from the first hot water discharge pipe 9 and the hot water temperature supplied from the intermediate hot water hot water pipe 10 remain. It is detected by the hot water thermistors 40a to 40e and controlled so that the outlet temperature becomes T1 + δT (° C.). A second mixing valve outlet temperature sensor is added to the outlet of the second mixing valve 13, and this second mixing is performed. The second mixing valve 13 may be controlled so that the temperature detected by the valve outlet temperature sensor becomes T1 + δT (K).

  Through the above operation, the boundary layer between the hot water in the upper part of the hot water storage tank 3 and the low temperature water in the bottom of the hot water storage tank 3 (hereinafter referred to as “medium temperature layer”), Medium temperature water is discharged from the intermediate temperature hot water discharge pipe 10 to the outside of the hot water storage tank 3, so that an increase in the water temperature (ΔT) at the bottom of the hot water storage tank 3 can be suppressed as shown in FIG.

  As a characteristic of the heat pump cycle 1, it is known that the coefficient of performance (COP) decreases as the incoming water temperature during the boiling operation, that is, the inlet water temperature of the water-refrigerant heat exchanger 5 increases. Therefore, by suppressing the rise in the water temperature at the bottom of the hot water storage tank 3 by the medium temperature hot water, the COP of the heat pump cycle 1 during the boiling operation can be improved and the energy saving can be improved.

  Next, the hot water operation mode will be described.

  FIG. 3 shows a control flowchart during pouring (bath hot water) into the bathtub 31. In FIG. 3, a bath hot water command by the user is input via the remote controller 50 (step 1). Thereby, the control means 51 detects a hot water bath. In addition to the operation of the remote controller 50 as described above, the detection of this hot water is not limited to the amount of continuous hot water supplied from the hot water storage tank detected by the hot water supply flow rate sensor 47a and the bath hot water supply flow rate sensor 47b. May be detected.

  Next, the temperature of the remaining hot water thermistors 40a to 40e installed on the wall surface of the hot water storage tank 3 to detect the remaining hot water amount is detected (step 2), and in order to determine whether the remaining hot water amount is large or small, It is compared whether the temperature of the hot water thermistor 40d is higher or lower than a predetermined temperature (step 3). Note that the amount of remaining hot water may be determined based on the amount of stored heat calculated by the plurality of remaining hot water thermistors 40. That is, it may be determined whether the heat storage heat amount is larger or smaller than a predetermined heat storage heat amount.

  For example, if the temperature (T40d) of the remaining hot water thermistor 40d at a height of 10 or less at step 3 is 60 ° C. or less at step 3, it is determined that the amount of remaining hot water is small, and the heat pump cycle 1 is operated in the hot water operation mode ( Step 4) and hot water bathing is performed using both hot water from the hot water storage tank 3 and hot water boiled in the heat pump cycle 1.

  On the other hand, when the temperature (T40d) of the remaining hot water thermistor 40d is higher than 60 ° C. in step 3, it is determined that the amount of remaining hot water is large, and the heat pump cycle 1 operation in the hot water operation mode is not performed (step 5). Do hot water bath with only hot water.

  Therefore, only when the amount of remaining hot water is relatively small, the heat pump cycle 1 is operated in the hot water operation mode to perform hot water for bathing. It is possible to reduce energy loss due to remaining hot water after the use of hot water is completed.

  Here, the presence or absence of activation of the heat pump cycle 1 is determined using the detected temperature of the remaining hot water thermistor 40d, but the presence or absence of activation of the heat pump cycle 1 is determined using a plurality of remaining hot water thermistors. Also good. For example, when the detected temperature of the remaining hot water thermistor 40d provided closest to the intermediate warm hot water pipe 10 is higher than 60 ° C. at a height equal to or lower than the intermediate hot water hot pipe 10, it is determined that the amount of remaining hot water is large. It is possible not to start the heat pump cycle 1 in the hot water operation mode. Further, in the height direction, the detection temperature of the remaining hot water thermistor 40c that is closest to the intermediate temperature hot water pipe 10 and is provided at substantially the same height as the intermediate temperature hot water pipe 10 is a temperature of 60 ° C. or less, and in the hot water operation mode. When the temperature is equal to or higher than the temperature of the hot water generated by the heat pump cycle 1, the hot water can be taken out from both the first hot water discharge pipe 9 and the medium temperature hot water supply pipe 10 and poured into the bathtub 31. Further, when the temperature detected by the remaining hot water thermistor 40c is lower than the temperature of hot water generated by the heat pump cycle 1 in the hot water operation mode, the heat pump cycle 1 is started and the hot water from the hot water storage tank 3 and the heat pump cycle 1 are used. It is possible to pour hot water into the bathtub 31 using both hot water generated by heating.

  In addition to the comparison of the remaining hot water thermistor temperature for grasping the remaining hot water amount, based on the accumulated hot water supply heat amount for each day (for example, the average for the past 7 days) calculated and stored by the hot water supply heat amount calculating means 52, It may be determined whether or not to operate the heat pump cycle 1 in the hot water operation mode when bath water is applied. FIG. 4 shows a control flowchart at the start of bath water in this case. Note that the term “one day” here does not have to be at midnight. For example, the integrated hot water supply calorie can be calculated with 3:00 am as the boundary of the day.

  As shown in FIGS. 4 and 5, the temperature of the remaining hot water thermistors 40a to 40e is detected (step 2), and in addition to determining whether the remaining hot water amount is large or small depending on the temperature of the remaining hot water thermistors 40a to 40e, Whether or not the heat pump cycle 1 is operated in the hot water operation mode is determined by comparison with the accumulated hot water supply heat amount Q every day (step 3).

  For example, even if the temperature (T40d) of the remaining hot water thermistor 40d is 60 ° C. or less and the remaining hot water amount is small, if the accumulated hot water supply heat amount Q per day is equal to or less than a predetermined value (hot water supply heat amount Qa), It is determined that the amount of remaining hot water is sufficient, and the operation of the heat pump cycle 1 in the hot water operation mode is not performed (step 5). On the other hand, even if the temperature (T40d) of the remaining hot water thermistor 40d is 60 ° C. or less, if the accumulated hot water supply heat amount Q per day is larger than the preset hot water supply heat amount Qa, it is determined that the remaining hot water amount is insufficient. The operation of the heat pump cycle 1 in the hot water operation mode is started (step 4).

  Here, as shown in FIG. 5, a plurality of hot water supply heat quantities (Qa, Qb, where Qa <Qb) may be used as a comparison target of the integrated hot water supply heat quantity Q. For example, when the accumulated hot water supply heat quantity Q is Qa or less, the operation of the heat pump cycle 1 in the hot water operation mode may not be performed regardless of the temperature of the remaining hot water thermistor 40d. Further, when the accumulated hot water supply heat quantity Q is larger than Qa and the detected temperature of the remaining hot water thermistor 40d is lower than the first predetermined value, the operation of the heat pump cycle 1 in the hot water operation mode may be performed. Good. Furthermore, you may use both the detection temperature of the remaining hot water thermistors (40d, 40e) adjacent to an up-down direction. For example, in the range of Qb <Q, the detected temperature of the remaining hot water thermistor 40d is higher than the first predetermined value (60 ° C.), and the detected temperature of the remaining hot water thermistor 40e adjacent to the lower hot water thermistor 40d is the first predetermined temperature. If the value is less than the value, the heat pump cycle may be operated in the hot water operation mode. Further, when the temperature detected by the lowermost remaining hot water thermistor 40e is higher than the first predetermined value, the operation of the heat pump cycle 1 in the hot water operation mode is not performed regardless of the integrated hot water supply heat amount Q. Good. Here, as the remaining hot water thermistor adjacent in the vertical direction, it is preferable to use a remaining hot water thermistor on the lower side of the medium temperature hot water pipe 10.

  Further, in addition to the comparison of the remaining hot water thermistor temperature for grasping the remaining hot water amount and the daily hot water supply heat amount calculated and stored by the hot water supply heat amount calculating means 52, the reheating heat amount calculating means 53 calculates and stores it. Whether or not the heat pump cycle 1 is operated in the hot water operation mode may be determined based on the accumulated heat retention heat amount (for example, the past seven days). FIG. 6 shows a control flowchart at the start of hot water in this case.

  As shown in FIG. 6 and FIG. 7, in addition to detecting the temperature of the remaining hot water thermistors 40a to 40e (step 2) and determining whether the remaining hot water amount is large or small depending on the temperature of the remaining hot water thermistors 40a to 40e, Whether or not the heat pump cycle 1 is operated in the hot water operation mode is determined by comparing with the total q of the accumulated hot water supply heat amount and the accumulated heat retention heat amount every day (step 3).

  For example, even if the temperature (T40d) of the remaining hot water thermistor 40d is 60 ° C. or less and the amount of remaining hot water is small, if the amount of heat q used for hot water supply and heat retention every day is equal to or less than a preset total heat amount qa Therefore, it is determined that the amount of remaining hot water is sufficient, and the operation of the heat pump cycle 1 in the hot water operation mode is not performed (step 5). On the other hand, even if the temperature (T40d) of the remaining hot water thermistor 40d is 60 ° C. or less, if the amount of heat q used for hot water supply and heat retention per day is greater than the preset total heat amount qa, the amount of remaining hot water is insufficient. It is judged that there is, and the operation of the heat pump cycle 1 in the hot water operation mode is started (step 4). As in the case shown in FIG. 5, a plurality of heat quantity and temperature thresholds may be provided.

  FIG. 8 shows a control sequence in the case where the operation of the heat pump cycle 1 is started together with the start of bath hot water in the hot water operation mode. In FIG. 8, when a bath hot water command is input by the user via the remote controller 50, the remaining hot water amount is detected as shown in FIG. 3 (or FIGS. 4 and 6), and it is determined that the remaining hot water amount is small. In this case, when the compressor 4 is activated, the heat pump cycle 1 is activated and the boiling pump 21 is operated.

  In addition, the pouring valve 19 is opened, and the four-way switching valve 18a is switched so that the boiling return pipe 33 and the hot water return pipe 36 communicate with each other.

  By this operation, the water at the bottom of the hot water storage tank 3 is conveyed to the water / refrigerant heat exchanger 5 by the boiling pump 21, where it is heated and exchanged with the refrigerant of the heat pump cycle 1, and then heated to the boiling return pipe 33. It passes through the four-way switching valve 18 a and the hot water return pipe 36 and once enters the hot water storage tank 3. Thereafter, it is mixed with hot water in the hot water storage tank 3, and the first outlet pipe 9, the second mixing valve 13, the first mixing valve 15, the bath pouring pipe 27, the pouring valve 19, the bath outlet pipe 29, and the bath return pipe 30. The hot water is poured into the bathtub 31 via

  At the beginning of the heat pump cycle 1, the outlet water temperature of the water-refrigerant heat exchanger 5 does not rise immediately, but the hot water flowing out of the water-refrigerant heat exchanger 5 passes through the hot water return pipe 36 and temporarily stores hot water. It enters the tank 3, is mixed with hot water in the hot water storage tank 3, and is supplied via the first hot water discharge pipe 9. Therefore, since hot water is stored in the hot water storage tank 3, the temperature of the hot water finally supplied from the hot water supply terminal and the bathtub does not fall below the target hot water temperature.

  FIG. 9 shows the relationship between the coefficient of performance (COP) of the heat pump cycle and the tapping temperature. Here, the coefficient of performance (COP) of the heat pump cycle in the hot water storage operation mode is represented by COPA, and the coefficient of performance (COP) of the heat pump cycle in the hot water operation mode is represented by COPB.

The hot water temperature in the hot water storage operation mode (detected temperature of the hot water temperature detection means 42) is generally 65 ° C. to 90 ° C., but the hot water temperature in the hot water operation mode is lower than the hot water temperature in the hot water operation mode (for example, , 35 ° C.), COPB can be improved over COPA and energy can be saved.

  As a specific means for lowering the hot water temperature in the hot water operation mode to be lower than the hot water temperature in the hot water operation mode, increasing the flow rate by increasing the rotation speed of the boiling pump 21 than in the hot water operation mode. Thus, the outlet temperature of the water-refrigerant heat exchanger 5 can be made lower than the outlet temperature in the hot water storage operation mode.

  FIG. 10 shows the relationship between the heating capacity of the heat pump cycle 1 and the compression ratio in the hot water operation mode. When the rotation speed of the compressor 4 is the same, the higher the compression ratio, the higher the discharge pressure, and the higher the discharge temperature and the higher the heating capacity. However, the characteristics increase slightly to the right (solid line).

  Furthermore, when the tapping temperature is the same, the discharge pressure is almost the same regardless of the heating capacity, but the higher the heating capacity, the higher the rotation speed of the compressor 4 and the lower the suction pressure, so the compression ratio increases. It becomes the characteristic of rising to the right (dashed line).

  For example, if the compression ratio that can ensure the reliability of the compressor 4 is d (broken line), it can be seen that the lower the heating capacity, the lower the rotation speed of the compressor 4 but the higher the hot water temperature.

  FIG. 11 shows the relationship between the heating capacity of the heat pump cycle 1 in the hot water operation mode and COPB, which is the coefficient of performance (COP) of the heat pump cycle in the hot water operation mode. In the compression ratio d in FIG. 10, when the heating capacity in the hot water storage operation mode is 4.5 (kW), COPB peaks at e1 (kW) lower than the heating capacity.

  However, in the hot water operation mode, hot water from the hot water storage tank 3 and hot water from the heat pump cycle 1 are used in combination, so that if the heating capacity of the heat pump cycle 1 is low, a large amount of hot water from the hot water storage tank 3 is required. Become.

  FIG. 12 shows the relationship between the heating capacity of the heat pump cycle 1 and the bath pouring COP in the hot water operation mode. Here, the bath pouring COP is represented by (Equation 1).

風呂注湯ＣＯＰは、貯湯運転モードにおけるＣＯＰＡ（例えば、加熱能力が４．５ｋＷ）、湯はり時に貯湯タンク３から使用した熱量、湯はり運転モードにおけるＣＯＰＢ（例えば、加熱能力を３．０ｋＷ、３．５ｋＷ、４．０ｋＷ、４．５ｋＷ、５．０ｋＷ）と湯はり時にヒートポンプサイクル１で沸き上げた熱量および湯はり熱量で表される。

The bath pouring COP has a COPA in the hot water storage operation mode (for example, a heating capacity of 4.5 kW), an amount of heat used from the hot water storage tank 3 during hot water filling, and a COPB in the hot water operation mode (for example, a heating capacity of 3.0 kW, 3 .5 kW, 4.0 kW, 4.5 kW, 5.0 kW) and expressed by the amount of heat boiled in the heat pump cycle 1 and the amount of hot water.

Here, the hot water heat amount is the heat amount of hot water that has entered the bathtub 31, and is represented by the sum of the heat amount used from the hot water storage tank 3 and the heat amount boiled in the heat pump cycle 1. The amount of heat boiled in the heat pump cycle 1 is calculated by the product of the heating capacity of the heat pump cycle 1 and the operation time. Therefore, the amount of heat used from the hot water storage tank 3 is calculated as the difference between the amount of heat of the hot water that has entered the bathtub 31 and the amount of heat that has been boiled in the heat pump cycle 1.

  As can be seen from FIG. 12, when the heating capacity in the hot water storage operation mode is 4.5 (kW), the bath pouring COP peaks at e2 (kW), which is larger than the heating capacity.

  FIG. 13 shows the relationship between the rotational speed of the compressor 4 and the bath pouring COP in the hot water operation mode. As in FIG. 12, for example, the compressor rotation speed is changed to 30 Hz, 35 Hz, 40 Hz, 45 Hz, and 50 Hz, and the bath pouring COP is calculated from the heating capability for each rotation speed.

  As can be seen from FIG. 13, in the hot water pouring COP, when the rotational speed of the compressor 4 in the hot water storage operation mode is 45 (Hz), for example, e3 (Hz) higher than the rotational speed peaks. .

  As described above, the bath hot water can be detected by a user command via the remote controller 50 or by detecting that the amount of continuous hot water supply from the hot water storage tank exceeds a predetermined amount. If pouring into the bathtub in the hot water operation mode is started by an instruction from 50, the heat pump cycle 1 can be started in the hot water operation mode almost simultaneously with the start of pouring into the bathtub. The amount of heat of boiling water is maximized. Therefore, since “the amount of heat boiled by the heat pump” in (Equation 1) is maximized and “the amount of heat used from the hot water storage tank” is minimized, the bath pouring COP can be maximized.

  Next, the stop time of the hot water operation mode will be described.

  FIG. 14 shows a control flowchart when the hot water bath is completed. In FIG. 14, during bath hot water while operating the heat pump cycle 1 in the hot water operation mode (step 1), when a predetermined amount of hot water is measured in the water level sensor 46 or the like, the completion of bath hot water is detected (step 2). ) And the temperature of the remaining hot water thermistors 40a to 40e installed on the wall surface of the hot water storage tank 3 in order to grasp the remaining hot water amount (step 3).

  Next, in order to determine whether the amount of remaining hot water is large or small, it is compared whether the temperature of the remaining hot water thermistor 40b is higher or lower than a predetermined temperature (step 4). For example, when the temperature (T40b) of the remaining hot water thermistor 40b is less than 60 ° C. in step 4, it is determined that the remaining hot water amount is small, and the operation of the hot water pump operation mode is shifted to the hot water storage operation mode without stopping the operation of the heat pump cycle 1. (Step 5). In the hot water storage operation mode, when a predetermined condition is satisfied, the hot water storage operation is completed (step 6), and the operation of the compressor 4 of the heat pump cycle 1 is stopped (step 7).

  On the other hand, when the temperature (T40b) of the remaining hot water thermistor 40b is 60 ° C. or higher at step 4, even if it is determined that the amount of remaining hot water is large, the remaining hot water thermistor 40c closest to the connecting portion of the intermediate hot water discharge pipe 10 When the temperature (T40c) is less than 30 ° C., it is determined that the intermediate temperature water is stored above the connecting portion of the intermediate temperature hot water pipe 10 (step 8), and the hot water beam operation is performed without stopping the operation of the heat pump cycle 1 The mode is shifted to the hot water storage operation mode (step 5). In the hot water storage operation mode, when a predetermined condition is satisfied, the hot water storage operation is completed (step 6), and the operation of the compressor 4 of the heat pump cycle 1 is stopped (step 7).

In addition to the comparison of the remaining hot water thermistor temperature for grasping the remaining hot water amount, the hot water supply heat amount calculating means 52 calculates and stores the daily hot water supply heat amount (for example, the average of the past seven days). It may be determined whether or not to continue the operation without stopping the operation of the heat pump cycle 1 by shifting from the hot water operation mode to the hot water storage operation mode after the hot water is completed.
FIG. 15 shows a control flowchart at the completion of bath water filling in this case.

  As shown in FIGS. 15 and 16, in addition to detecting the temperature of the remaining hot water thermistors 40a to 40e (step 3) and determining whether the amount of remaining hot water is large or small depending on the temperature of the remaining hot water thermistors 40a to 40e, Compared with the daily hot water supply heat quantity Q, the heat pump cycle 1 is shifted from the hot water operation mode to the hot water storage operation mode to determine whether or not to continue the operation (step 4).

  For example, even if the temperature (T40a) of the remaining hot water thermistor 40a is less than 60 ° C. and the amount of remaining hot water is relatively small, if the accumulated hot water supply heat amount Q per day is equal to or less than a preset hot water supply heat amount Qc, the remaining hot water amount Is determined to be sufficient, and the process proceeds to a determination of whether or not the medium-temperature water is stored above the connecting portion of the medium-temperature hot water pipe 10 (step 8). On the other hand, even if the temperature (T40a) of the remaining hot water thermistor 40a is less than 60 ° C., if the accumulated hot water supply heat amount Q per day is greater than the preset hot water supply heat amount Qc, it is determined that the remaining hot water amount is insufficient. The heat pump cycle 1 is shifted from the hot water operation mode to the hot water storage operation mode, and the operation is continued (step 5).

  Here, as shown in FIG. 16, a plurality of hot water supply heat amounts (Qc, Qd, where Qc <Qd) may be used as a comparison target of the accumulated hot water supply heat amount Q. For example, when the accumulated hot water supply heat quantity Q is equal to or less than Qc, the operation of the heat pump cycle in the hot water operation mode may be stopped regardless of the temperature of the remaining hot water thermistor 40a. Further, when the accumulated hot water supply heat quantity Q is larger than Qc and the detected temperature of the remaining hot water thermistor 40a is lower than the first predetermined value, the hot water operation mode may be shifted to the hot water storage operation mode.

  Further, in addition to the comparison of the remaining hot water thermistor temperature for grasping the remaining hot water amount and the comparison of the accumulated hot water supply heat amount for each day calculated and stored by the hot water supply heat amount calculating means 52, the reheating heat amount calculating means 53 calculates Based on the accumulated heat storage amount per day (for example, the past seven days) stored in the memory, the hot pump operation mode is shifted from the hot water operation mode to the hot water storage operation mode after completion of the hot water bath without stopping the operation of the heat pump cycle 1. It may be determined whether or not to continue driving. FIG. 17 shows a control flowchart when the bath water filling is completed in this case.

  As shown in FIGS. 17 and 18, in addition to detecting the temperature of the remaining hot water thermistors 40a to 40e (step 3) and determining whether the remaining hot water amount is large or small depending on the temperature of the remaining hot water thermistors 40a to 40e, Compared with the amount of heat q used for daily hot water supply and heat retention, the heat pump cycle 1 is shifted from the hot water operation mode to the hot water storage operation mode to determine whether or not to continue the operation (step 4).

  For example, even if the temperature (T40a) of the remaining hot water thermistor 40a is less than 60 ° C. and the amount of remaining hot water is relatively small, the amount of heat q used for daily hot water supply and heat insulation is not more than a preset total heat amount qc. Then, it is determined that the amount of remaining hot water is sufficient, the amount of remaining hot water is determined to be sufficient, and the process proceeds to a determination as to whether or not intermediate hot water is stored above the connecting portion of the intermediate hot water discharge pipe 10 (step 8). On the other hand, even if the temperature (T40a) of the remaining hot water thermistor 40a is less than 60 ° C., if the amount of heat q used for daily hot water supply and heat insulation is greater than the preset total heat amount qc, the amount of remaining hot water is insufficient. Judgment is made, the heat pump cycle 1 is shifted from the hot water operation mode to the hot water storage operation mode, and the operation is continued (step 5).

Therefore, when the amount of remaining hot water is small, the compressor is shifted from the hot water operation mode to the hot water storage operation mode without stopping, so that the start-up loss can be reduced as compared with the case of newly operating in the hot water storage operation mode. In addition, when the amount of remaining hot water is large, the hot water operation mode is completed and the compressor operation is stopped, so that energy loss due to excess hot water can be reduced, and even if the amount of remaining hot water is sufficiently large, When hot water is stored above the intermediate temperature hot water discharge pipe 10, the hot water heated and generated by the heat pump cycle 1 in the hot water storage operation mode is stored from the approximate top of the hot water storage tank 3, and the intermediate temperature water reaches the vicinity of the intermediate temperature hot water discharge pipe 10. By pushing down, the medium temperature water in the hot water storage tank 3 can be taken out.

  FIG. 19A is a diagram showing changes in the temperature distribution in the hot water storage tank when there is an intermediate temperature hot water circuit. 61 is the temperature distribution before performing hot water in the hot water operation mode, 62 is the temperature distribution after performing hot water in the hot water operation mode, and 63 is the temperature distribution after performing hot water supply and boiling operation thereafter. Show.

  By performing hot water heating in the hot water operation mode, the temperature of the upper part of the hot water storage tank 3 decreases (61 → 62). Thereafter, by performing hot water supply and boiling operation while performing medium temperature hot water, the angle of the temperature distribution changes from α → β (β> α) (62 → 63). This means that the temperature distribution deteriorated by hot water in hot water operation mode has been improved by the medium temperature hot water, and it is possible to avoid a decrease in the efficiency of the subsequent night boiling operation and save energy. Sex is not impaired.

  Moreover, since the boiling pipe 35 is connected to the approximate top of the hot water storage tank 3, the hot water heated by the heat pump cycle 1 is stored in the top of the hot water storage tank 3 in the hot water storage operation mode, and to the bathtub in the hot water operation mode. Even after the hot water is poured, the hot water temperature in the hot water storage tank 3 can be kept high. Thereby, even when hot water such as hot water for Karan or hot water in a bathtub is required, the comfort and convenience of the user are not impaired.

  FIG. 19B is a diagram showing a change in temperature distribution in the hot water storage tank when there is no intermediate temperature hot water supply circuit. 61 is the temperature distribution before performing hot water in the hot water operation mode, 64 is the temperature distribution after performing hot water in the hot water operation mode, and 65 is the temperature distribution after performing hot water supply and boiling operation thereafter. Show.

  By performing hot water heating in the hot water operation mode, the temperature of the upper part of the hot water storage tank 3 decreases (61 → 64). Thereafter, even if hot water supply or boiling operation is performed, the angle of temperature distribution does not change γ (β> α> γ) (64 → 65). This means that the temperature distribution deteriorated by performing hot water in hot water operation mode could not be improved because there was no intermediate temperature hot water circuit, and the efficiency of night boiling operation performed thereafter was reduced. Energy conservation will be impaired.

  Accordingly, since the intermediate temperature hot water supply circuit is provided, the hot water is poured in the hot water operation mode, the temperature distribution of the hot water storage tank 3 that is slightly broken can be improved, the lowering of the operation efficiency of the heat pump unit 2 can be avoided, and the energy is saved. Sex is not impaired.

  As described above, the intermediate temperature hot water discharge pipe 10 for taking out hot water from between the top and bottom of the hot water storage tank 3 is provided, and the intermediate temperature hot water supply pipe 10 is arranged below the hot water return pipe 36. it can. The hot water heated and generated by the heat pump cycle 1 in the hot water operation mode flows from the upper part of the hot water discharge pipe 10 in the hot water storage tank 3. Here, the hot water that does not flow out from the first hot water pipe 9 and flows down to the lower part in the hot water storage tank 3 can be taken out from the intermediate hot water hot water pipe 10, thereby reducing the amount of intermediate temperature water in the hot water storage tank 3, The temperature of the water flowing into the heat pump cycle 1 can be kept low, and the COP related to the boiling of the heat pump cycle 1 can be improved.

By connecting the hot water return pipe 36 to the hot water storage tank 3, the temperature of the hot water supplied from the hot water storage tank 3 to the bathtub is substantially the same as the temperature of the hot water in the upper part of the hot water storage tank 3. The temperature of the hot water to be supplied can be recognized as the hot water storage temperature detected by the hot water storage temperature detection means 40. Therefore, while using the temperature generated by heating in the hot water operation mode for the hot water beam, it is possible to easily control the hot water temperature to the bath so as not to fall below a desired temperature.

(Embodiment 2)
FIG. 20 is a configuration diagram of a heat pump hot water supply apparatus according to the second embodiment of the present invention.

  The difference between the present embodiment and the first embodiment is that the hot water return pipe 36 is shared with the boiling pipe 35 and the four-way switching valve 18a is replaced with the three-way switching valve 18b. is there.

  Thus, according to the present embodiment, the hot water return pipe 36 can be reduced, and not only the same effect can be obtained at a low cost, but also a heat dissipation loss from the pipe can be reduced, and energy saving performance can be achieved. improves.

  In addition, the boiling piping which supplies the hot water boiled by the heat pump cycle to a hot water storage tank can also be connected to the approximate top part of a hot water storage tank. Thereby, hot water is supplied into the hot water storage tank from the upper part of the hot water storage tank. Therefore, by taking out hot water from the upper part of the hot water storage tank, it is possible to respond to a load that requires high-temperature hot water, such as hot water supply for hot water or hot water in a bathtub, without running out.

(Embodiment 3)
FIG. 21 is a configuration diagram of a heat pump hot water supply apparatus according to the third embodiment of the present invention.

  The third embodiment is different from the second embodiment in that the boiling pipe 35 is connected not to the hot water storage tank 3 but to the first hot water discharge pipe 9 and the number of pipe connections to the hot water storage tank 3 main body is reduced. This is a reduction.

  Thus, according to the third embodiment of the present invention, the number of pipe connections to the hot water storage tank body can be reduced, and not only the same effect can be obtained at a low cost, but also heat dissipation from the pipe connection. Loss can be reduced and energy saving is improved.

  As described above, the heat pump hot water supply device according to the present invention is excellent in energy saving without impairing the comfort and convenience of the user, so that it can be applied to a hot water supply device for home use as well as a heat source and a hot water storage tank. It can also be applied to business use in the system it has.

DESCRIPTION OF SYMBOLS 1 Heat pump cycle 3 Hot water storage tank 4 Compressor 5 Water refrigerant | coolant heat exchanger 6 Pressure reducing means 7 Evaporator 9 1st hot water pipe 10 Medium temperature hot water pipe 11 Water supply pipe 12 Water supply branch part 13 2nd mixing valve (intermediate mixing valve)
14 Third mixing valve (hot water mixing valve)
15 First mixing valve (bath mixing valve)
16 Hot water branch pipe 17 Hot water junction pipe 18a Four-way switching valve 19 Hot water valve 20 Pressure reducing valve 21 Boiling pump 27 Bath pouring pipe 28 Hot water pipe 31 Bath 32 Heating pipe 33 Heating return pipe 40a-40e Hot water storage temperature detection means (Remaining hot water thermistor)
41 Incoming water temperature detecting means 42 Hot water temperature detecting means (hot water temperature sensor)
43a Hot water supply temperature sensor 43b Bath hot water temperature sensor 44 Reheating temperature sensor 47a Hot water flow rate sensor 47b Bath hot water flow rate sensor 51 Control means 52 Hot water supply heat amount calculation means 53 Reheating heat amount calculation means

Claims (5)

A heat pump cycle in which a compressor, a water refrigerant heat exchanger, a decompression means, and an evaporator are connected by refrigerant piping;
A hot water storage tank for storing hot water heated and generated by the heat pump cycle;
Piping for returning the hot water generated by heating in the heat pump cycle to the top of the hot water storage tank;
A first hot water pipe for removing hot water from the upper part of the hot water storage tank;
Hot water storage temperature detecting means for detecting the temperature of hot water stored in the hot water storage tank;
Control means for executing at least a plurality of operation modes,
The plurality of operation modes are:
A hot water storage operation mode in which hot water generated by the heat pump cycle is stored in the hot water storage tank; and
While generating hot water having a temperature lower than that of the hot water storage operation mode by the heat pump cycle, the hot water generated by the heat pump cycle is temporarily returned to the upper part of the hot water tank via a pipe. A hot water beam operation mode used for pouring into the bathtub through the first hot water discharge pipe ,
The coefficient of performance of the heat pump cycle in the hot water operation mode is higher than the coefficient of performance of the heat pump cycle in the hot water storage operation mode, and
The control means shifts to the hot water storage operation mode when the temperature detected by the hot water storage temperature detection means is lower than a first predetermined value when the hot water operation mode is completed. Hot water flow rate detecting means for detecting the hot water flow rate of hot water supplied to the hot water supply terminal and the bathtub,
A hot water supply temperature detecting means for detecting a hot water supply temperature of hot water supplied to the hot water supply terminal and the bathtub,
The control means includes a hot water supply calorific value calculating means for calculating and storing an accumulated hot water supply heat amount per day from the hot water flow rate and the hot water supply temperature,
The control means, when the accumulated hot water supply heat amount is larger than a second predetermined value, and when the temperature detected by the hot water storage temperature detecting means is lower than a first predetermined value when the hot water operation mode is completed, The heat pump hot water supply device according to claim 1, wherein the heat pump operation mode is shifted to a hot water storage operation mode. A bath reheating circuit having a bath heat exchanger for exchanging heat between the hot water in the hot water storage tank and the hot water in the bathtub,
The control means has a reheating heat amount calculating means for calculating a heat retention heat amount of the hot water in the hot water storage tank used in the bath reheating circuit and storing it as an accumulated heat retention heat amount every day,
In the hot water operation mode, the control means detects the hot water storage temperature when the sum of the integrated hot water supply heat amount and the integrated heat retention heat amount is greater than the second predetermined value and when the hot water operation mode is completed. The heat pump hot water supply apparatus according to claim 2, wherein when the temperature detected by the means is lower than a first predetermined value, the hot water storage operation mode is entered. According to any one of claims 1 to 3, wherein the obtaining Bei the hot water storage tank medium temperature hot water pipe for taking out the hot water from the hot water storage tank below the piping and the first tapping pipe back to the upper part of Heat pump water heater. The heat pump hot water supply apparatus according to any one of claims 1 to 4, wherein the heat pump cycle operates in a state where a pressure on a high pressure side exceeds a critical pressure of the refrigerant.

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