JP2014052154A - Water heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce noise due to boiling-up operation in a night time zone.SOLUTION: A water heater 1 includes a plurality of hot water supply units 2 each of which performs a boiling-up operation in a night time zone. Each of the hot water supply units 2 includes a heat pump unit 4 and a hot water storage tank 10 for storing hot water heated by the heat pump unit 4. One of the hot water supply units 2 has an earlier timing of starting up the boiling-up operation and an earlier timing of finishing the boiling-up operation in the night time zone than the others of the hot water supply units 2.

Description

  The present invention relates to a hot water supply apparatus including a plurality of hot water supply units each having a hot water storage tank and a heat pump unit.

  The hot water supply apparatus includes a hot water storage tank that stores hot water supplied to the hot water supply terminal, and a heat pump unit that heats the hot water stored in the hot water storage tank (see, for example, Patent Document 1). The heat pump unit has a refrigerant circuit including a compressor and a water heat exchanger. The hot water supply apparatus heats the low-temperature water taken out from the hot water storage tank by heat exchange with the refrigerant in the water heat exchanger and returns it to the tank. This boiling operation is automatically performed at night time when electricity charges are low.

  Moreover, as a hot water supply apparatus for business use, there is one provided with a plurality of hot water supply units each having a hot water storage tank and a heat pump unit (heat source unit) (see, for example, Patent Document 2).

JP 2002-122362 A JP 2005-134064 A

  However, in a conventional hot water supply apparatus having a plurality of hot water supply units, since all the hot water supply units simultaneously perform a boiling operation during the night time, the operation sound of the heat pump unit is increased. Therefore, noise is a problem when the location of the hot water supply device is close to a house.

  Then, an object of this invention is to provide the hot water supply apparatus which can reduce the noise by the boiling operation in a night time zone.

  A hot water supply apparatus according to a first aspect of the present invention includes a plurality of hot water supply units that perform boiling operation during night time, and the hot water supply unit includes a heat pump unit and a hot water storage tank that stores hot water heated by the heat pump unit. The one hot water supply unit is characterized in that the start timing and the end timing of the boiling operation in the night time zone are earlier than another hot water supply unit.

  In this hot water supply apparatus, two hot water supply units out of a plurality of hot water supply units have different boiling time periods during the nighttime period, and therefore, compared with a case where all the hot water supply units simultaneously perform the boiling operation during the nighttime period. Thus, noise caused by boiling operation during night hours can be reduced.

  A hot water supply apparatus according to a second invention is characterized in that, in the first invention, the hot water supply unit that starts boiling operation first in a night time zone starts boiling operation at a start time of the night time zone. To do.

  In this hot water supply device, since the first boiling operation in the night time zone is started at the start time of the night time zone, it is possible to prevent hot water shortage when the amount of hot water supply in the night time zone is large.

  A hot water supply apparatus according to a third aspect of the present invention is the hot water supply apparatus according to the first or second aspect, wherein the hot water supply unit that starts the boiling operation last in the night time zone can end the boiling operation at the end time of the night time zone. The boiling operation is started at the start time determined based on the remaining hot water amount in the hot water storage tank.

  In this hot water supply apparatus, since the boiling operation last started in the night time zone ends around the end time of the night time zone, the boiling operation of all the hot water supply units ends in the middle of the night time zone. In comparison, it is possible to reduce the heat dissipation of hot water in the hot water storage tank at night time.

  A hot water supply apparatus according to a fourth aspect of the present invention is that in any one of the first to third aspects, when the boiling operation of one of the hot water supply units is completed, another hot water supply unit starts the boiling operation. Features.

  In this hot water supply apparatus, two hot water supply units among a plurality of hot water supply units do not overlap in the time zone during which the boiling operation is performed, and therefore noise can be reduced more reliably.

  As described above, according to the present invention, the following effects can be obtained.

  In the first invention, two hot water supply units out of the plurality of hot water supply units have different boiling time periods during the night time period, and therefore when all the hot water supply units simultaneously perform the boiling operation during the night time period. In comparison, noise caused by boiling operation during night time can be reduced.

  In the second invention, since the first boiling operation in the night time zone is started at the start time of the night time zone, it is possible to prevent hot water shortage when the amount of hot water supply in the night time zone is large.

  In the third aspect of the invention, the boiling operation last started in the night time zone ends at the end time of the night time zone, so that the boiling operation of all the hot water supply units ends in the middle of the night time zone. Compared with, it is possible to reduce the heat dissipation of hot water in the hot water storage tank at night time.

  In 4th invention, since the hot water supply unit among the several hot water supply units does not overlap the time zone which performs boiling operation, it can reduce noise more reliably.

It is a figure which shows the structure of the hot water supply apparatus which concerns on 1st Embodiment of this invention. It is a piping system diagram of the hot water supply unit with which the hot water supply device is provided. In 1st Embodiment, it is a flowchart which shows the procedure which determines the start time of the boiling operation in a night time zone. In 1st Embodiment, it is a graph which shows the specific example of boiling operation in case the total value of boiling required time is below the time of a night time zone. In 1st Embodiment, it is a graph which shows an example of the boiling operation in case the total value of boiling required time exceeds the time of a night time zone. In 1st Embodiment, it is a graph which shows an example of the boiling operation in case the total value of boiling required time exceeds the time of a night time zone. In 2nd Embodiment, it is a graph which shows an example of the boiling operation in case the total value of boiling required time exceeds the time of a night time zone. In 3rd Embodiment, it is a graph which shows an example of boiling operation when the total value of boiling required time exceeds the time of a night time zone.

<First Embodiment>
Hereinafter, the hot water supply apparatus according to the first embodiment of the present invention will be described.
As shown in FIG. 1, a hot water supply device 1 of the present embodiment is a device for supplying hot water to a hot water supply terminal, and includes four hot water supply units 2 (2A to 2D), a hot water supply terminal, and four hot water supply units 2. And a hot water supply pipe 6 for connecting a water supply source and the four hot water supply units 2 to each other. As shown in FIGS. 1 and 2, each hot water supply unit 2 has a hot water storage unit 3 having a hot water storage tank 10 and two heat pump units 4 connected to the hot water storage unit 3. The heat pump unit 4 is for heating the hot water stored in the hot water storage tank 10.

  Each hot water supply unit 2 is provided with two refrigerant circuits 8 and two boiling circuits 7. The refrigerant circuit is provided in the heat pump unit 4, and the boiling circuit 7 is provided across the hot water storage unit 3 and the heat pump unit 4.

The refrigerant circuit 8 includes a compressor 21, a water heat exchanger 22, an electric expansion valve 23, an air heat exchanger 24, and a refrigerant pipe that connects them in order, for example, a refrigerant such as CO ₂ circulates. To do. The refrigerant circuit 8 also includes a gas heat exchanger 25 for exchanging heat between the high-temperature and high-pressure refrigerant coming out of the water heat exchanger 22 and the cold and low-pressure refrigerant coming out of the air heat exchanger 24. A fan 26 for adjusting the capacity of the air heat exchanger 24 is disposed in the vicinity of the air heat exchanger 24.

  The refrigerant compressed by the compressor 21 is cooled by heat exchange with hot water in the water heat exchanger 22 and then further cooled by the gas heat exchanger 25. Thereafter, the refrigerant is depressurized by the electric expansion valve 23, heated by the heat exchange with the outside air in the air heat exchanger 24, and returned to the compressor 21.

  The boiling circuit 7 is a circuit in which the hot water storage tank 10, the pump 31, the water heat exchanger 22, and the three-way valve 32 are connected in order. The hot water storage tank 10, the pump 31, and the three-way valve 32 are provided in the hot water storage unit 3, and the water heat exchanger 22 is provided in the heat pump unit 4.

  A hot water supply outlet 11 and an upper return port 12 are provided in the upper part of the hot water storage tank 10, and a water supply port 13, an outlet 14, and a lower return port 15 are provided in the lower part of the hot water storage tank 10. . The upper return port 12, the outlet 14, and the lower return port 15 are connected to the boiling circuit 7. The upper return port 12, the outlet 14, and the lower return port 15 are shared by the two boiling circuits 7.

  A plurality of tank thermistors 16 for detecting the temperature of the hot water in the hot water storage tank 10 are attached to the outer surface of the hot water storage tank 10 side by side in the vertical direction. It is possible to detect how much hot water remains in the hot water storage tank 10 based on the temperature detected by the tank thermistor 16 (detection of remaining hot water).

  The three-way valve 32 switches the outlet side of the water heat exchanger 22 so as to communicate with either the upper return port 12 or the lower return port 15, and the temperature of the hot water heated by the water heat exchanger 22 ( It can be switched according to the temperature When the tapping temperature is low (for example, immediately after the start of the boiling operation), the three-way valve 32 is switched so that the water heat exchanger 22 communicates with the lower return port 15, and when the tapping temperature approaches the target tapping temperature, The three-way valve 32 is switched so that the water heat exchanger 22 communicates with the upper return port 12.

  During the boiling operation, the compressor 21 and the fan 26 of the refrigerant circuit 8 are driven, and the pump 31 of the boiling circuit 7 is driven, and hot water is taken out from the outlet 14 of the hot water storage tank 10, and the water heat exchanger 22 is supplied. The hot water is heated in the water heat exchanger 22 and then returned to the hot water storage tank 10 from the upper return port 12 or the lower return port 15.

  The hot water storage unit 3 includes a hot water supply pipe 33 that connects the hot water supply outlet 11 of the hot water storage tank 10 and the hot water supply pipe 5, and a water supply pipe 34 that connects the water supply port 13 of the hot water storage tank 10 and the water supply pipe 6.

  When hot water is supplied to the hot water supply terminal, hot water is discharged from the hot water supply outlet 11 of the hot water storage tank 10, and at the same time, water from the water supply source is supplied into the hot water storage tank 10 from the water supply port 13. Therefore, except for the case where all the hot water in the hot water storage tank 10 is heated to a high temperature, the temperature of the hot water in the hot water storage tank 10 is high at the top and low at the bottom. The flow rates discharged from the four hot water storage tanks 10 at the time of one hot water supply differ because the lengths of the hot water supply pipes from the four hot water storage tanks 10 to the hot water supply terminals are different. Therefore, the remaining hot water amounts of the four hot water storage tanks 10 may be different.

  Next, the control part (illustration omitted) of the hot water supply apparatus 1 is demonstrated. The control unit controls the boiling operation of the four hot water supply units 2. The control unit controls the four hot water supply units 2 to perform a boiling operation during a night time zone (for example, from 22:00 to 7:00) where the electricity rate is inexpensive. The boiling operation in this case is referred to as nighttime automatic boiling operation. Moreover, a control part controls so that the hot water supply unit 2 which has the hot water storage tank 10 performs boiling operation, when the remaining hot water amount of the hot water storage tank 10 becomes less than predetermined amount irrespective of a time slot | zone. The boiling operation in this case is referred to as a hot water boiling operation.

  When the boiling operation start condition based on the time or the amount of remaining hot water is satisfied for one hot water supply unit 2, the control unit drives the compressors 21 and the fans 26 of the two heat pump units 4 included in the hot water supply unit 2, and the hot water supply. The two pumps 31 of the hot water storage unit 3 included in the unit 2 are driven to start the boiling operation. During the boiling operation, the control unit controls the three-way valve 32 based on the temperature of the hot water heated by the water heat exchanger 22. Further, the controller ends the boiling operation when the temperature of the hot water in the hot water storage tank 10 reaches the target boiling temperature.

  Hereinafter, a method of determining the start time (hereinafter referred to as boiling start time) of the nighttime automatic boiling operation of the four hot water supply units 2 by the control unit will be described with reference to the flowchart shown in FIG.

  The control unit determines the boiling start time before the night time zone. First, the control unit calculates the required boiling time of each of the four hot water supply units 2 from the amount of remaining hot water in each of the four hot water storage tanks 10 (step S1).

  When the total time of the four boiling required times is equal to or less than the time of the night time zone (hereinafter referred to as night time) (step S2, NO), the control unit, based on the calculated boiling required time, The boiling start times of the four hot water supply units 2 are determined so that the boiling operation times of the four hot water supply units 2 do not overlap (step S3). More specifically, the boiling operation time of the four hot water supply units 2 is packed on the start time side of the night time zone (prepared) or on the end time side of the night time zone (post-packed). Thus, the boiling start time is determined. Whether to use front-packing or back-packing may be determined in advance, or may be selected by operating a remote controller.

  Fig.4 (a) is a specific example in the case of determining the boiling start time by the last preparation. In Fig.4 (a), the start time of night time is made into the boiling start time of the hot water supply unit 2A. Also, the time obtained by adding the required boiling time of the hot water supply unit 2A to the boiling start time of the hot water supply unit 2A is set as the boiling start time of the hot water supply unit 2B. The description of the boiling start time of the hot water supply units 2C and 2D is the same as that of the hot water supply unit 2B, and will be omitted.

  FIG.4 (b) is a specific example in the case of determining the boiling start time by backpacking. In FIG. 4B, the time obtained by subtracting the required boiling time of the hot water supply unit 2A from the end time of the night time zone is set as the boiling start time of the hot water supply unit 2A. The time obtained by subtracting the required boiling time of the hot water supply unit 2B from the boiling start time of the hot water supply unit 2A is set as the boiling start time of the hot water supply unit 2B. The description of the boiling start time of the hot water supply units 2C and 2D is the same as that of the hot water supply unit 2B, and will be omitted.

  Since the boiling time in FIG. 4 (a) and FIG. 4 (b) is calculated based on the amount of remaining hot water before the night time zone, when hot water is supplied during the night time zone, The actual boiling time is longer than the boiling time in the figure. Therefore, the next boiling operation may start before the boiling operation of one hot water supply unit 2 ends. In addition, in the case of back-packing, the last boiling operation may end after the end time of the night time zone.

  When the total time of the four boiling required times exceeds the night time (step S2, YES), the control unit sets the four boiling required times for each group to be equal to or less than the night time. The hot water supply units 2 are divided into a plurality of groups (step S4).

For example, as shown in FIG. 5, when the required boiling time of the hot water supply units 2A to 2D is 5 hours, 4 hours, 3 hours, and 3 hours, the hot water supply units 2A and 2C are group 1 and the hot water supply units 2B, 2B, Let 2D be Group 2.
For example, as shown in FIG. 6, when the required boiling time of the hot water supply units 2A to 2D is 6 hours, 5 hours, 3.5 hours, and 3.5 hours, the hot water supply unit 2A is group 1 and Units 2B and 2C are group 2 and hot water supply unit 2D is group 3.

  The control unit determines the boiling start time of the hot water supply units 2 in the odd-numbered groups and sets the hot water supply in the even-numbered groups so that the boiling operations of the hot water supply units 2 in the odd-numbered groups are arranged in the above-mentioned order. The boiling start times of the hot water supply units 2 in the even-numbered groups are determined so that the boiling operations of the units 2 are arranged in the last order (step S5) (see FIGS. 5 and 6).

  In the hot water supply apparatus 1 of the present embodiment, the start time of the nighttime automatic boiling operation of the four hot water supply units 2 is determined by one or both of the pre-packing and the post-packing. Therefore, at least two hot water supply units 2 among the plurality of hot water supply units 2 are out of time during which the boiling operation is performed during the night time. Therefore, compared with the case where all the hot water supply units 2 perform the boiling operation at the same time during the night time, noise due to the boiling operation during the night time can be reduced.

  In the present embodiment, when there is no hot water supply during the night time period, when the boiling operation of one hot water supply unit 2 is completed, another hot water supply unit 2 starts the boiling operation. The hot water supply unit 2 does not overlap the time zone during which the boiling operation is performed. Therefore, noise can be reduced more reliably.

  In addition, when the boiling start time is determined by the last preparation, the first boiling operation in the night time zone is started at the start time in the night time zone, so the hot water runs out when there is a large amount of hot water supply in the night time zone. Can be prevented.

  In addition, when the boiling start time is determined by backpacking, the boiling operation that was started last in the night time zone ends at the end time of the night time zone, so all hot water supply units are in the middle of the night time zone. Compared with the case where the boiling operation is completed, it is possible to reduce the heat radiation of the hot water in the hot water storage tank 10 during the night time.

Second Embodiment
Next, a hot water supply apparatus according to a second embodiment of the present invention will be described. However, about the thing which has the structure similar to the said 1st Embodiment, the description is abbreviate | omitted suitably using the same code | symbol.
The hot water supply apparatus of this embodiment differs from the first embodiment in the method for determining the start time of nighttime automatic boiling operation of four hot water supply units by the control unit. Other configurations are the same as those in the first embodiment.

  When determining the start time of the nighttime automatic boiling operation, the control unit first determines the boiling time of the four hot water supply units 2 based on the remaining hot water amount of the four hot water storage tanks 10 as in the first embodiment. calculate.

  When the total time of the four boiling required times is equal to or less than the night time, the controller is configured so that the boiling operation times of the four hot water supply units 2 are pre-packed or post-packed as in the first embodiment. The boiling start times of the four hot water supply units 2 are determined.

  When the total time of the four boiling times exceeds the night time, the control unit arranges the boiling operation times of the four hot water supply units 2 from the front end to the rear end and still in the night time zone. When all the boiling operation times do not fit, the boiling start times of the four hot water supply units 2 are determined by arranging the remaining boiling operation times in front-alignment. A specific example is shown in FIG. In FIG. 7, the boiling operation time of the four hot water supply units 2 is within the night time zone only by the front packing and the back packing. When there is hot water supply during the night time, the timing of actually ending the boiling operation may be later than that in FIG.

  In the hot water supply apparatus of the present embodiment, as in the first embodiment, it is possible to reduce noise due to the boiling operation during the night time period, as compared to the case where all the hot water supply units 2 perform the boiling operation simultaneously during the night time period.

<Third Embodiment>
Next, a hot water supply apparatus according to a third embodiment of the present invention will be described. However, about the thing which has the structure similar to the said 1st Embodiment, the description is abbreviate | omitted suitably using the same code | symbol.
The hot water supply apparatus of this embodiment differs from the first embodiment in the method for determining the start time of nighttime automatic boiling operation of four hot water supply units by the control unit. Other configurations are the same as those in the first embodiment.

  When determining the start time of the nighttime automatic boiling operation, the control unit first determines the boiling time of the four hot water supply units 2 based on the remaining hot water amount of the four hot water storage tanks 10 as in the first embodiment. calculate.

  When the total time of the four boiling required times is equal to or less than the night time, the controller is configured so that the boiling operation times of the four hot water supply units 2 are pre-packed or post-packed as in the first embodiment. The boiling start times of the four hot water supply units 2 are determined.

  When the total time of the four boiling required times exceeds the night time, the control unit subtracts the difference between the total time of the four boiling required times and the night time by one from the number of the hot water supply units 2 ( In this embodiment, it is divided by 3). The control unit arranges the boiling-up times of the four hot water supply units 2 by shifting them from the start time to the end time of the night time zone while overlapping the calculated time by the calculated time. Determine the start time. That is, the time obtained by subtracting the calculated time from the time obtained by adding the required boiling time to the boiling start time of one hot water supply unit 2 (scheduled boiling end time) is the boiling start time of another hot water supply unit 2. And Specific example 1 is shown in FIG. In FIG. 8, the total value of the four boiling required times is 12 hours, and the overlapping time of the boiling operation is 1 hour. When there is hot water supply during the night time, the timing of actually ending the boiling operation may be later than that in FIG.

  In the hot water supply apparatus of the present embodiment, as in the first embodiment, it is possible to reduce noise due to the boiling operation during the night time period, as compared to the case where all the hot water supply units 2 perform the boiling operation simultaneously during the night time period.

  As mentioned above, although embodiment of this invention was described, it should be thought that the specific structure of this invention is not limited to the said 1st-3rd embodiment. The scope of the present invention is shown not only by the description of the above-described embodiment but also by the scope of claims for patent, and further includes meanings equivalent to the scope of claims for patent and all modifications within the scope.

  In the first and second embodiments described above, when determining the boiling start time by backpacking, the last boiling start time in the night time zone is the time obtained by subtracting the boiling required time from the end time of the night time zone. However, even if there is hot water supply during the night time zone, the boiling time is subtracted from the time slightly earlier (for example, 1 hour) than the end time of the night time zone so that the boiling operation can be completed within the night time zone. The time may be the boiling start time.

  The method for determining the start time of the nighttime automatic boiling operation of the four hot water supply units 2 is such that one hot water supply unit 2 starts and ends more quickly than another hot water supply unit 2. If it is a method, methods other than the said 1st-3rd embodiment may be sufficient. In the first to third embodiments, the boiling start times of all the hot water supply units 2 are determined before the night time zone, but based on the remaining hot water amount in the night time zone, The boiling start time of some hot water supply units 2 may be determined.

  In the first to third embodiments, the nighttime automatic boiling operation of the four hot water supply units 2 is always performed at different times, but the nighttime automatic boiling operation of all the hot water supply units 2 is performed simultaneously, It may be shifted as in the third embodiment or selected with a remote controller.

  In the said 1st-3rd embodiment, although the number of the heat pump units 4 which one hot water supply unit 2 has is two, it may be one or three or more. Further, the number of heat pump units 4 may be different for each of the plurality of hot water supply units 2.

  In the said 1st-3rd embodiment, although the number of the hot water supply units 2 which the hot water supply apparatus 1 has is four, as long as it is plural, it may be three or less, or may be five or more.

  If this invention is utilized, the noise by the boiling operation in a night time zone can be reduced.

DESCRIPTION OF SYMBOLS 1 Hot water supply apparatus 2 (2A-2D) Hot water supply unit 3 Hot water storage unit 4 Heat pump unit 7 Boiling circuit 8 Refrigerant circuit 10 Hot water storage tank

Claims (4)

Equipped with multiple hot water supply units that perform boiling operation at night time,
The hot water supply unit includes a heat pump unit and a hot water storage tank for storing hot water heated by the heat pump unit,
One of the hot water supply units has a timing for starting and ending boiling-up operation in a night time zone earlier than another hot water supply unit.   The hot water supply device according to claim 1, wherein the hot water supply unit that starts boiling operation first in a night time zone starts boiling operation at a start time of the night time zone.   Boiling operation at the start time determined based on the remaining amount of hot water in the hot water storage tank so that the hot water supply unit that starts boiling operation at the end of the night time period can finish the boiling operation at the end time of the night time period The hot water supply apparatus according to claim 1, wherein the hot water supply apparatus is started.   The hot water supply apparatus according to any one of claims 1 to 3, wherein when the boiling operation of one of the hot water supply units is finished, another hot water supply unit starts the boiling operation.