JP6596242B2 - Heat pump water heater - Google Patents

Description

  The present invention relates to a heat pump type water heater provided with a hot water storage tank.

  2. Description of the Related Art As a heat pump type hot water supply apparatus, one that uses a heat pump cycle, boils low-temperature water into hot water having a desired temperature, and stores it in a hot water storage tank is known. More specifically, low-temperature hot water stored in the lower part of the hot water storage tank is heated by a heat source unit using a heat pump cycle, converted into hot hot water and returned to the upper part of the hot water storage tank, thereby boiling the hot water in the hot water storage tank. It is supposed to be raised.

  Hot water obtained by boiling the water in the hot water storage tank is used for hot water supply in the home, etc. However, since a general heat pump type water heater has a small heating capacity and requires time to complete the boiling operation, the boiling operation is performed at midnight. The system uses hot water stored in hot water for the next morning.

  Moreover, it has the function to change the temperature at the time of boiling operation according to a user's hot water supply usage (for example, 65 degreeC-90 degreeC), and adjust the heat storage amount in a hot water storage tank. As mentioned above, heat pump water heaters perform boiling operation at midnight, so that it is possible to set a pause that does not perform boiling operation as a response to a day when the user is absent due to travel and the use of hot water does not occur It has improved energy saving.

  When the user sets the pause, the boiling operation is not performed, but the hot water generated by the boiling operation before the pause setting and the remaining hot water remaining for the use of hot water until immediately before the setting remain in the hot water storage tank. become. Since this remaining hot water is not used for hot water supply, the temperature drops due to heat dissipation from the hot water storage tank. If the remaining hot water temperature in the hot water storage tank immediately before setting is, for example, 80 ° C, the setting is canceled due to the temperature decrease due to heat dissipation. Sometimes it drops to, for example, 50 ° C to 60 ° C.

  For this reason, in the boiling operation after canceling the suspension setting, the boiling operation is completed within a short time from the start of the boiling operation due to the influence of the remaining hot water in the hot water storage tank, and hot water runs out during hot water supply, Since the temperature of water entering the heat pump unit during the boiling operation is high (for example, 30 ° C. to 60 ° C.), there is a problem that the efficiency of the heating operation in the heat pump unit decreases and the energy saving performance is impaired. In order to solve such a problem, at the time of boiling operation after canceling the suspension setting, a proposal has been made to perform operation with the boiling target temperature as the maximum hot water storage temperature (Patent Document 1).

Japanese Patent No. 3840988

  By the way, in the case of the technique shown in Patent Document 1, since the target boiling temperature after the suspension is canceled is set to the maximum hot water storage temperature, the problem of running out of hot water is solved, but the operation of the heat pump unit at the maximum hot water storage temperature is reduced. Therefore, energy saving performance is impaired. In addition, when the amount of hot water used before the pause setting is small, the target boiling temperature is set low as an operation to reduce the amount of heat storage. When the amount is small, there is a problem that a large amount of remaining hot water is generated in the hot water storage tank.

  Therefore, the present invention provides a heat pump water heater that can be operated with an appropriate amount of boiling heat without impairing energy saving even when the user cancels the pause setting of the heat pump water heater. is there.

  The above-described problems are solved by the invention described in the claims.

  According to the present invention, it is possible to provide a heat pump type hot water heater that can be operated with an appropriate amount of boiling heat without losing energy-saving performance when a pause setting for stopping a heating operation by a heat pump unit is canceled by a user. it can.

The block diagram of the heat pump type water heater which concerns on embodiment. 6 is an operation flowchart at the time of pause setting according to the first embodiment. The schematic diagram regarding the relationship between the boiling temperature and the heat pump unit operating efficiency at the time of the temperature of incoming water to the heat pump unit being 50 ° C. 9 is an operation flowchart at the time of setting a pause according to the second embodiment. 12 is an operation flowchart at the time of pause setting according to the third embodiment. 10 is an operation flowchart at the time of pause setting according to the fourth embodiment.

  Embodiments of the present invention will be described in detail with reference to the drawings as appropriate.

  FIG. 1 is a configuration diagram of the heat pump type water heater of the first embodiment. This water heater is composed of a hot water storage unit 1 and a heat pump unit 2, and is connected by a heat pump water inlet connection pipe 9 and a heat pump hot water outlet connection pipe 10.

  A hot water storage tank 3 for storing hot water boiled by the heat pump unit 2 is provided in the hot water storage unit 1, and water is supplied from the water supply pipe 4 to the lower part of the hot water storage tank 3 through the water supply connection pipe 5. A hot water storage tank temperature sensor 11 including 11a to 11e is provided on the surface of the hot water storage tank 2 in order to grasp the hot water temperature at each height in the tank.

  On the other hand, the heat pump unit 2 houses a refrigeration cycle for boiling water in the hot water storage tank 3 into warm water and a water-refrigerant heat exchanger. Boiling of the water in the hot water storage tank 3 is performed using the heat pump unit 2. Water is supplied to the heat pump unit 2 through a heat pump water inlet connection pipe 9 connected to the lower part of the hot water storage tank 3. The high-temperature and high-pressure refrigerant discharged from the compressor in the refrigeration cycle provided in the heat pump 2 and the supplied water are boiled into hot water by exchanging heat in the water-refrigerant heat exchanger. The hot water boiled by the heat pump unit 2 is returned to the upper part of the hot water storage tank 3 by the heat pump hot water connection pipe 10 connected to the upper part of the hot water storage tank 3. Carbon dioxide refrigerant is used as the refrigerant for the refrigeration cycle. However, R410A and R32 which are fluorocarbon refrigerants, propane which is a natural refrigerant, or the like may be used as the refrigerant.

  Hot water stored in the hot water storage tank 3 is supplied to a hot water supply facility (not shown) in which the user uses hot water via a hot water supply connection pipe 6 provided at the top, a mixing valve 7 and a hot water supply pipe 8. At this time, the hot water in the hot water storage tank 2 and the water supplied from the branch pipe from the water supply connection pipe 5 can be mixed in the mixing valve 7 and mixed with the hot water temperature desired by the user to supply hot water. is there. The mixing valve 7 is controlled so that the temperature detected by the hot water supply temperature sensor 12 becomes the target temperature desired by the user.

  The hot water storage unit 1 is provided with a hot water storage unit control unit 13 for controlling the operation of the entire heat pump type hot water heater. The hot water storage unit control unit 13 includes a CPU, a ROM, a RAM, various interfaces, an electronic circuit, and the like. The hot water heater of the present embodiment is comprehensively controlled according to a program stored therein.

  The hot water storage unit control unit 13 is connected to a hot water storage tank temperature sensor 11, a hot water supply temperature sensor 12, a heat pump control unit (not shown), a remote controller 14, and a hot water supply flow rate sensor 15. The remote controller 14 is installed in the user's home and functions as a user interface.

  The remote control 14 is provided with a pause setting function for stopping the boiling operation by the heat pump unit 2 for a desired number of days when the user is absent due to travel or the like and the heat pump hot water heater is not used. When the stop setting is made, the information is transmitted from the remote controller 14 to the hot water storage unit control unit 13, and the hot water storage unit 13 stops the boiling operation by the heat pump unit 2 for the set number of days.

  Further, the hot water storage unit control unit 13 learns the amount of hot water used by the user of the heat pump water heater daily from the information obtained from the hot water storage tank temperature sensor 11 and the hot water supply flow rate sensor 15, and estimates the amount of hot water stored in the hot water storage tank 3. Thus, the target boiling temperature of the hot water storage tank 3 by the heat pump unit 2 is determined. Further, since the boiling operation of the hot water storage tank 3 by the heat pump unit 2 in the heat pump type hot water heater is generally performed at midnight when the amount of electric power used is small, the hot water storage unit controller 13 is obtained from the hot water tank temperature sensor 11. The boiling operation start time in midnight is calculated from the amount of remaining hot water in the stored hot water tank 3, the target boiling temperature determined before the boiling operation, and the heating capacity of the heat pump unit 2, and the hot water storage tank after the boiling operation Control to reduce loss due to heat radiation from 3 is performed.

  Next, the operation of the water heater of the present embodiment will be described using the flowchart of FIG.

  When the user operates the remote controller 14 to set the pause setting for n days, for example, the hot water storage unit control unit 13 maintains the pause setting until the set n days elapses, and the hot water storage tank 3 by the heat pump unit 2 is maintained. The water boiling operation is stopped (step S1).

  When n days have passed and the pause setting is canceled, the hot water storage unit control unit 13 measures the temperature of hot water in the hot water storage tank 3 using the temperature sensor 11 (step S2). Then, among the temperatures measured by the temperature sensors 11a to 11e, the maximum temperature (for example, 50 ° C.) is determined as the hot water temperature in the tank, and the boiling efficiency ( COP) is being improved. In this embodiment, a temperature at which boiling can be performed with the highest boiling efficiency from the measured hot water temperature in the tank is set as the boiling target temperature (step S3).

  Here, the relation between the boiling target temperature and the boiling efficiency in the case where the tank hot water temperature is 50 ° C. will be described with reference to FIG. In the case where the hot water temperature in the tank is 50 ° C., if the target boiling temperature is set high, for example, 90 ° C., the boiling efficiency decreases as the boiling temperature rises, so it is desirable to suppress the boiling target temperature to some extent. . On the other hand, if the boiling target temperature is lowered to, for example, 65 ° C., there arises a problem that the temperature difference between the inlet and outlet of the heat pump unit 2 is reduced and the boiling efficiency is deteriorated. Therefore, it is necessary to raise the boiling target temperature to some extent. There is also. Therefore, by setting an appropriate boiling target temperature that can minimize both adverse effects, it is possible to achieve boiling at the highest efficiency. If the highest efficiency boiling target temperature can be set for every hot water in the tank, the boiling target temperature that achieves the highest efficiency can be selected regardless of the hot water temperature in the tank when the pause setting is canceled. Note that the boiling target temperature corresponding to the hot water temperature in each tank may be obtained by experiment and stored in the hot water storage unit control unit 13 in advance, or the mathematical characteristics may be stored in the hot water storage unit control unit 13. Accordingly, the boiling target temperature that achieves the highest efficiency may be calculated.

  After setting the boiling target temperature in step S3, the start time of the boiling operation by the heat pump unit 2 is set from the amount of remaining hot water in the hot water storage tank 3 and the target boiling temperature measured in step S2, and the start time has elapsed. Then, the hot water boiling operation in the hot water storage tank by the heat pump unit 2 is started (step S4). At this time, if the boiling operation start time has not elapsed, steps S2 and S3 are repeated to measure the hot water temperature in the tank and set the boiling target temperature, so that the standby time until the operation start time elapses. Also, it is possible to follow changes in hot water temperature in the hot water storage tank 3 that may be generated due to heat radiation from the tank or use of hot water by the user, and to perform the boiling operation by the heat pump unit 2 more efficiently. Is possible. After the tank boiling operation is started, the operation is continued until the condition for ending the boiling operation is satisfied, and after the condition is satisfied, the tank boiling operation by the heat pump unit 2 is ended (step S5).

  According to the heat pump type water heater of Example 1 as described above, after the user cancels the pause setting for stopping the heating operation by the heat pump unit, the boiling target optimal for the hot water temperature in the tank at the start of boiling is reached. Since boiling is performed by setting the temperature, it is possible to achieve the effect of being able to operate with an appropriate amount of boiling heat without impairing energy saving performance.

  Next, the operation | movement flowchart at the time of the rest setting of the heat pump type water heater of Example 2 is demonstrated using FIG. The description up to step S7 common to the first embodiment is omitted.

  In step S3 of the first embodiment, the target boiling temperature that is the highest efficiency corresponding to the hot water temperature in the tank is set. In step S8 of the second embodiment, after the hot water temperature in the tank (for example, 50 ° C.) is determined, A tank boiling target temperature (for example, 75 ° C.) obtained by adding α ° C. (for example, 25 ° C.) to the measured hot water temperature in the tank is set as a boiling target value in the next boiling operation (step S8).

  After setting the boiling target temperature, the start time of the boiling operation by the heat pump unit 2 is set from the amount of remaining hot water in the hot water storage tank 3 and the target boiling temperature measured in step S7. After the start time has elapsed, the heat pump The hot water boiling operation in the hot water storage tank by the unit 2 is started (step S9). At this time, if the boiling operation start time has not elapsed, steps S7 and S8 are repeated to measure the hot water temperature in the tank and set the boiling target temperature, thereby waiting for the operation start time to elapse. It is also possible to follow changes in hot water temperature in the hot water storage tank 3 that may be generated by heat radiation from the tank or use of hot water by the user. After the tank boiling operation is started, the operation is continued until the condition for ending the boiling operation is satisfied, and after the condition is satisfied, the tank boiling operation by the heat pump unit 2 is ended (step S10).

  According to the heat pump type water heater of Example 2 as described above, when the pause setting for stopping the heating operation by the heat pump unit is canceled by the user, the boiling target temperature after the cancellation of the pause is inadvertently increased. Or, since it is possible to avoid a decrease in efficiency of the boiling operation due to a low boiling target temperature with respect to the remaining hot water temperature in the hot water storage tank 3, there is an effect that the operation can be performed with an appropriate boiling heat amount without impairing energy saving performance. be able to.

  Next, the operation | movement flowchart at the time of the rest setting of the heat pump type water heater of Example 3 is demonstrated using FIG. Note that the description of the points in common with the first or second embodiment will be omitted.

  When the user sets the stop (the number of stop days is n days) by the remote controller 14 (step S11), the latest value of the boiling target temperature of the hot water storage tank 3 by the heat pump unit 2 at the set time is set. Store (step S12).

  The hot water storage unit controller 13 stops the boiling operation of the water in the hot water storage tank 3 by the heat pump unit 2 until the set n days elapses, and cancels the pause setting after elapse of n days (step S13). After canceling the pause setting, the hot water storage unit control unit 13 measures the temperature of the hot water in the hot water storage tank 3 using the temperature sensor 11 (step S14). Of the temperatures of the temperature sensors 11a to 11e measured at this time, the highest temperature (for example, 50 ° C.) is determined as the hot water temperature in the tank. After determining the hot water temperature in the tank (for example, 50 ° C.), when the hot water temperature in the tank is boiled, the boiling target temperature at which the efficiency of the boiling operation in the heat pump unit 2 is maximized is set as the highest efficiency boiling target temperature. (Step S15). The maximum efficiency boiling target temperature may be measured by experiments as detailed in the description of the first embodiment, and the temperature at which the obtained efficiency is maximized may be stored in the hot water storage unit controller 13 as a numerical target value. In addition, the hot water storage unit control unit 13 may formulate the characteristics and calculate them.

  After setting the maximum efficiency boiling target temperature, the value of the latest boiling target temperature (step S11) stored when the pause is set is compared with the value of the maximum efficiency boiling target temperature, and the target becomes a high value. The temperature is set to the tank boiling target temperature (step S16). After setting the tank boiling target temperature, after setting the start time of boiling operation by the heat pump unit 2 from the remaining hot water amount in the hot water storage tank 3 and the tank boiling target temperature measured in step S14, and after the start time has elapsed The boiling operation of the hot water in the hot water storage tank by the heat pump unit 2 is started (step S17).

  At this time, if the boiling operation start time has not elapsed, steps S14 to S16 are repeated, and the standby time until the operation start time elapses by measuring the hot water temperature in the tank and setting the tank boiling target temperature. In addition, it is possible to follow the change in hot water temperature in the hot water storage tank 3 that may be generated due to heat dissipation from the tank or the use of hot water by the user, and the boiling operation by the heat pump unit 2 is performed more efficiently. It becomes possible. After the tank boiling operation is started, the operation is continued until the condition for ending the boiling operation is satisfied, and after the condition is satisfied, the tank boiling operation by the heat pump unit 2 is ended (step S18).

  According to the heat pump type water heater of Example 3 as described above, when the user cancels the pause setting for stopping the heating operation by the heat pump unit, the energy consumption is not impaired, and the daily amount of hot water used by the user In addition, it is possible to achieve an operational effect that enables operation with an appropriate amount of boiling heat in consideration of the above.

  Next, the operation | movement flowchart at the time of the rest setting of the heat pump type water heater of Example 4 is demonstrated using FIG. Note that the description of the points in common with the first to third embodiments is omitted.

  When the user of the heat pump hot water heater sets the stop (the number of stop days is n) by the remote controller 14 (step S19), the boiling target temperature of the hot water storage tank 3 by the heat pump unit 2 at the set time Is stored (step S20). The hot water storage unit control unit 13 stops the boiling operation of the water in the hot water storage tank 3 by the heat pump unit 2 until the set n days elapses, and cancels the pause setting after the elapse of n days (step S21). After canceling the pause setting, the hot water storage unit controller 13 measures the temperature of the hot water in the hot water storage tank 3 using the temperature sensor 11 (step S22). Of the temperatures of the temperature sensors 11a to 11e measured at this time, the highest temperature (for example, 50 ° C.) is determined as the hot water temperature in the tank. After the tank hot water temperature (for example, 50 ° C.) is determined, a tank boiling target temperature (for example, 75 ° C.) obtained by adding α ° C. (for example, 25 ° C.) to the measured tank water temperature is set as an addition-type boiling target value. (Step S23). After setting the additive boiling target temperature, the value of the latest boiling target temperature (step S20) stored when the pause is set is compared with the value of the additive boiling target temperature, and the target becomes a high value. The temperature is set to the tank boiling target temperature (step S24). After setting the tank boiling target temperature, after setting the start time of the boiling operation by the heat pump unit 2 from the remaining hot water amount in the hot water storage tank 3 and the tank boiling target temperature measured in step S22, and after the start time has elapsed Then, the boiling operation of the hot water in the hot water storage tank by the heat pump unit 2 is started (step S25). At this time, if the boiling operation start time has not elapsed, steps S22 to S24 are repeated, and the standby time until the operation start time elapses by measuring the hot water temperature in the tank and setting the tank boiling target temperature. In addition, it is possible to follow the change in hot water temperature in the hot water storage tank 3 that may be generated due to heat dissipation from the tank or the use of hot water by the user, and the boiling operation by the heat pump unit 2 is performed more efficiently. It becomes possible. After the tank boiling operation is started, the operation is continued until the condition for ending the boiling operation is satisfied, and after the condition is satisfied, the tank boiling operation by the heat pump unit 2 is ended (step S26).

  According to the heat pump type water heater of Example 4 as described above, when the pause setting for stopping the heating operation by the heat pump unit is canceled by the user, the boiling target temperature after the cancellation of the pause is inadvertently increased. Or, since it is possible to avoid lowering the efficiency of the boiling operation due to the lower boiling target temperature relative to the remaining hot water temperature in the hot water storage tank 3, the energy saving performance is not impaired, and an appropriate amount considering the daily hot water usage amount of the user is also considered. The effect which can be drive | operated with the amount of boiling heat can be show | played.

1 hot water storage unit, 2 heat pump unit, 3 hot water storage tank, 4 water supply piping,
5 water supply connection piping, 6 hot water supply connection piping, 7 mixing valve, 8 hot water supply piping,
9 Heat pump water inlet connection pipe, 10 Heat pump hot water outlet connection pipe,
11 Hot water storage tank temperature sensor, 11a Hot water storage tank temperature sensor-1,
11b Hot water storage tank temperature sensor-2, 11c Hot water storage tank temperature sensor-3,
11d Hot water storage tank temperature sensor-4, 11e Hot water storage tank temperature sensor-5,
12 Hot water temperature sensor, 13 Hot water storage unit controller, 14 Remote control 15 Hot water flow rate sensor

Claims (3)

A heat pump for boiling liquid,
A tank for storing liquid boiled by the heat pump;
A temperature sensor for measuring the temperature of the liquid in the tank;
In a heat pump type hot water heater provided with a control unit capable of setting the heat pump to rest for a predetermined period of time by a user operation,
The boiling target temperature used in the boiling operation after the pause setting is canceled is a temperature obtained by adding a predetermined temperature to the liquid temperature in the tank measured by the temperature sensor before the boiling operation. Heat pump type water heater. A heat pump for boiling liquid,
A tank for storing liquid boiled by the heat pump;
A temperature sensor for measuring the temperature of the liquid in the tank;
In a heat pump type hot water heater provided with a control unit capable of setting the heat pump to rest for a predetermined period of time by a user operation,
The boiling target temperature used in the boiling operation after the pause setting is canceled is the temperature at which the boiling efficiency from the liquid temperature in the tank measured by the temperature sensor before the boiling operation is maximized. A heat pump type hot water heater characterized by comparing the latest boiling target temperature stored when the person sets a pause and setting the temperature to the higher one . A heat pump for boiling liquid,
A tank for storing liquid boiled by the heat pump;
A temperature sensor for measuring the temperature of the liquid in the tank;
In a heat pump type hot water heater provided with a control unit capable of setting the heat pump to rest for a predetermined period of time by a user operation,
The boiling target temperature used in the boiling operation after the pause setting is canceled, the temperature obtained by adding a predetermined temperature to the liquid temperature in the tank measured by the temperature sensor before the boiling operation, and the user pauses. A heat pump type hot water heater characterized by comparing the latest boiling target temperature memorized at the time of setting and setting the higher one of them.

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