JP2009287794A - Heat pump type water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat pump type water heater preventing running-out of hot water and reducing operation noise of a heat pump. <P>SOLUTION: This heat pump type water heater for heating a liquid for hot water supply by using a heat pump unit 2 and storing the heated liquid in a hot water storage tank 1, is provided with: an outside air temperature sensor 2c detecting an outside air temperature; a plurality of temperature sensors 4a-4d detecting the amount of hot water remaining in the hot water storage tank 1; and a heating capacity variable means (control section 16) for making a heating capacity of the heat pump unit 2 variable. The control section 16 is disposed to vary the heating capacity of the heat pump unit 2 according to the outside air temperature in performing a defrosting operation by the heat pump unit 2 and the amount of hot water remaining in the hot water storage tank 1 in a heating-up operation in a nighttime zone, and to operate the heat pump unit 2 while maximizing the heating capacity of the heat pump unit regardless of the outside air temperature and the amount of hot water remaining in the hot water storage tank 1 in a heating-up operation in a daytime zone. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a heat pump type hot water heater that heats a hot water supply liquid using a heat pump and stores the heated liquid in a hot water storage tank.

  Conventional heat pump type water heaters are equipped with heating capacity variable means that varies the heating capacity of the heat pump according to the amount of remaining hot water in the hot water storage tank, and when there is a large amount of remaining hot water, the heating capacity is reduced to reduce operating noise. (For example, refer to Patent Document 1).

Japanese Unexamined Patent Publication No. 2003-90606 (first page, FIGS. 1, 2)

  However, in the heat pump type water heater as described above, the heating capacity is always reduced when the amount of remaining hot water is large, and in the winter when the outside air temperature is low, the heating capacity is reduced other than the boiling immediately before the defrosting operation. As a result, the heating ability to boil hot water is insufficient, and there is a problem of running out of hot water. Further, in winter when the outside air temperature is low, frost adheres to the air heat exchanger of the heat pump unit, and there is a problem that the flow of the air flowing through the air heat exchanger changes and the operation sound of the heat pump increases.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a heat pump type water heater that can prevent hot water from running out and reduce the operation sound of the heat pump.

The heat pump type water heater according to the present invention is a heat pump type water heater that heats a liquid for hot water supply using a heat pump and stores the heated liquid in a hot water storage tank.
An outside air temperature detecting means for detecting the outside air temperature, a remaining hot water amount detecting means for detecting the remaining hot water amount in the hot water storage tank, and a heating capacity variable means for varying the heating capacity of the heat pump,
The heating capacity variable means varies the heating capacity of the heat pump in accordance with the outside air temperature and the amount of remaining hot water in the hot water storage tank during the boiling operation at night time, and the outside air temperature and the hot water storage during the daytime heating operation. Regardless of the amount of hot water in the tank, the heating capacity of the heat pump is set to the maximum heating capacity and is operated.

  According to the heat pump type water heater according to the present invention, the heating capacity of the heat pump is varied according to the outside air temperature and the amount of remaining hot water in the hot water storage tank at the time of boiling at night time, and the outside air temperature at the time of boiling at day time Regardless of the amount of remaining hot water in the hot water storage tank, the heating capacity of the heat pump cycle is set to the maximum heating capacity and operated to set the heating capacity of the heat pump small when the outside air temperature is low and the amount of remaining hot water is large. The operation sound of the heat pump can be reduced and the operation sound of the heat pump can be reduced while preventing hot water from running out.

Embodiment 1 FIG.
1 is a configuration diagram of a heat pump type water heater in Embodiment 1 of the present invention, FIG. 2 is a flowchart of control in Embodiment 1 of the present invention, and FIG. 3 is a boiling start temperature and a boiling stop in a daytime period. It is a table | surface which shows the relationship of temperature.
In FIG. 1, a hot water storage tank 1 is connected by a heating circuit 3 to a heat pump unit 2 that is a heating means. The heat pump unit 2 includes a heat pump circuit in which a compressor, a hot water supply heat exchanger, an expansion valve, an air heat exchanger 2d, and an accumulator are sequentially connected by a refrigerant pipe, a fan 2a, a defrost temperature sensor 2b, and an outside air temperature sensor 2c. Yes.
The heating circulation circuit 3 is connected to the heat pump unit 2 at the upper and lower parts of the hot water storage tank 1, and a circulation pump 18 is provided in a pipe portion connecting the lower part of the hot water storage tank 1 and the heat pump unit 2. The water taken out from the lower part is guided into the heat pump unit 2, boiled into hot water in the heat pump unit 2, and returned to the upper part of the hot water storage tank 1.
First to third temperature sensors 4a to 4c are provided on the outer circumference of the hot water storage tank 1 at different heights at appropriate intervals, and a fourth lower side of the hot water storage tank of the heating circulation circuit 3 is also provided. A temperature sensor 4d is provided, and the first to fourth temperature sensors 4a to 4d function as remaining hot water amount detecting means for detecting the remaining hot water amount in the hot water storage tank 1, and detect the temperature of the hot water at that position. The hot water storage tank temperature sensor 5 is provided in the upper part of the hot water storage tank 1 and detects the temperature of the hot water heated by the heat pump unit 2 and returned to the upper part of the hot water storage tank 1. The electric hot / cold water mixing valve 6 serving as a mixing means generates hot water with an appropriate temperature by changing the mixing ratio of hot water and water by electric control.

On the other hand, one end of the hot water supply pipe 7 is connected to the upper part of the hot water storage tank 1, the other end is connected to the hot water supply port of the electric hot water mixing valve 6, and hot water stored in the hot water storage tank 1 is supplied to the electric hot water mixing valve 6. It is piping for doing. The hot water storage tank temperature sensor 5 is attached in the vicinity of the hot water supply pipe 7.
One end of the water supply pipe 9 is connected to a water source such as a water pipe, is attached to the water supply pipe 9, and the other end is connected to the lower part of the hot water storage tank 1 via a pressure reducing valve 11 that reduces the water source water pressure.
One end of the water supply bypass pipe 8 is connected to the water supply pipe 9 downstream of the pressure reducing valve 11, and the other end is connected to the water supply port of the electric hot / cold water mixing valve 6 to supply water from the water source to the electric hot water / mixing valve 6.
The feed water temperature sensor 17 detects the temperature of water passing through the feed water bypass pipe 8. One end of the mixed hot water supply pipe 10 is connected to the mixed hot water outlet of the electric hot water mixed valve 6 and the other end is connected to a hot water outlet such as a faucet. The hot water supply pipe 7 in the vicinity of the upper part of the hot water storage tank 1 is provided with a relief valve 12 for releasing (discharging) the hot water in the hot water storage tank 1 which has undergone volume expansion during boiling. The water flow detection means 13 detects the flow rate flowing through the mixed hot water supply pipe 10. The hot water supply temperature sensor 14 is attached to the mixed hot water supply pipe 10 in order to perform temperature correction by the electric hot water mixing valve 6 and detects the temperature of the hot water flowing through the mixed hot water supply pipe 10.

  The control unit 16 serving as a control device includes a hot water supply temperature and a boiling temperature set by the remote controller 15, first to fourth temperature sensors 4 a to 4 d, a hot water storage tank temperature sensor 5, a hot water supply temperature sensor 14, and a water flow detection means 13. In addition to controlling the heat pump unit 2 and the electric hot / cold water mixing valve 6 and the like, it also discriminates between the night time zone and the day time zone, and the remaining hot water amount detected by the first to fourth temperature sensors 4a to 4d and the outside air A heating capacity varying means is provided for varying the heating capacity of the heat pump unit 2 in accordance with the outside air temperature detected by the temperature sensor 2c.

The operation of the first embodiment configured as described above will be described with reference to FIG.
First, the water sent from the water source to the water supply pipe 9 passes through the pressure reducing valve 11, is depressurized and flows into the hot water storage tank 1, and the hot water storage tank 1 is always kept full. In this state, the heating operation by the heat pump unit 2 is performed.
When the boiling operation is performed, the water in the hot water storage tank 1 is taken out from the lower part of the hot water storage tank 1 to the heating circulation circuit 3 by the operation of the circulation pump 18, exchanges heat with the heat pump unit 2, and the hot water storage set by the remote controller 15. The temperature is raised to a temperature (for example, 90 ° C.) and returned to the upper part of the hot water storage tank 1 (arrow a in FIG. 1).
Thereby, in the hot water storage tank 1, 90 degreeC hot water is stored little by little from the upper part.

When the temperature detected by the fourth temperature sensor 4d becomes equal to or higher than a certain temperature (for example, 70 ° C.), it is determined that the hot water storage tank 1 has been completely heated, and the boiling by the heat pump unit 2 is terminated. At this time, the heating performance of the boiling by the heat pump unit 2 is high when the temperature of the water entering the heat pump unit 2 is low, but the heating efficiency of the boiling is high when the temperature of the entering water is high. Has a deteriorating property. The hot water in the hot water storage tank 1 expanded by the hot water storage is discharged from the relief valve 12. Further, when the hot water in the hot water storage tank 1 decreases due to the hot water supply, the re-boiling operation is performed according to the detected temperatures of the first to third temperature sensors 4a to 4c.
For example, the temperature detected by the second temperature sensor 4b at the intermediate position of the hot water storage tank 1 is 44 ° C. during the time period from 17:00 to 23:00 when a large amount of hot water such as preparation for dinner or hot water in the bath is required. When it becomes below, the re-boiling operation is started, and when the temperature detected by the third temperature sensor 4c becomes 46 ° C. or higher, the re-boiling operation is stopped.

  When the faucet or the like is opened to supply hot water, the hot water stored in the hot water storage tank 1 and the water source water pass through the hot water supply pipe 7 and the water supply bypass pipe 8, respectively, to the electric hot water mixing valve 6, where the mixed hot water supply pipe The control unit 16 controls the mixing ratio of hot water and water in the electric hot / cold water mixing valve 6 so that the temperature detected by the hot water supply temperature sensor 14 attached to 10 becomes a set temperature set by the remote controller 15. At this time, when the water flow detection means 13 attached to the mixed hot water supply pipe 10 detects whether hot water is flowing through the mixed hot water supply pipe 10 and detects the flow of hot water (for example, a flow rate of 1.5 L / min or more), Feedback control is started on the electric hot / cold water mixing valve 6 by the temperature detected by the temperature sensor 14, the hot water storage tank temperature sensor 5 and the feed water temperature sensor 17.

  The defrosting operation of the heat pump unit 2 is performed in order to prevent frost from getting on the air heat exchanger 2d during the winter boiling operation in which the outside air temperature is low, and the heating capacity of the heat pump being reduced. When the temperature detected by the defrost temperature sensor 2b falls below a predetermined value (for example, −3 ° C.) during the boiling operation, the defrosting operation is started, and the temperature detected by the defrost temperature sensor 2b becomes equal to or higher than the predetermined value (for example, 5 ° C.). Then, the defrosting operation is stopped.

Next, the above operation will be described in more detail with reference to the flowchart of FIG.
In step S1, the control unit 16 detects the energization time zone, and determines whether or not it is a night time zone in step S2. If it is a night time zone, the process proceeds to step S3, and if not, the process proceeds to step S8. Here, the night time zone is from 23:00 to 7:00.

In step S3, it is determined whether or not the temperature detected by the outside air temperature sensor 2c provided in the heat pump unit 2 is 5 ° C. or less. If it is 5 ° C. or less, the process proceeds to step S4.
The outside air temperature of 5 ° C. or lower is a temperature at which the heat pump unit 2 is likely to enter the defrosting operation during the boiling operation, and frost adheres to the air heat exchanger 2d immediately before the defrosting operation and the heat pump unit 2 The wind flow by the fan 2a changes and the driving sound becomes very loud.

  Step S4 detects the amount of remaining hot water in the hot water storage tank 1 from the detected temperatures of the first to fourth temperature sensors 4a to 4d.

In step S5, the control unit 16 determines whether or not the remaining hot water amount in the hot water storage tank 1 is equal to or less than a predetermined value. If it is equal to or less than the predetermined value, the process proceeds to step S6.
For example, when detecting whether or not the remaining hot water amount in the hot water storage tank 1 is 150 L or less, it is determined that the remaining hot water amount is 150 L or less when the temperature detected by the second temperature sensor 4 b is 44 ° C. or less.

In step S6, the control unit 16 sets the heating capacity of the heat pump unit 2 to be large and operates at a maximum heating capacity of 6.0 KW. In step S7, the control unit 16 sets the heating capacity of the heat pump unit 2 to be small, It operates with a heating capacity of 4.5 KW.
Incidentally, the operation sound of the heat pump unit 2 has a measurement result of 49 dB immediately before the defrosting operation with the maximum heating capacity of 6.0 KW and 47 dB immediately before the defrosting operation with the heating capacity of 4.5 KW.

In step S9, the heating operation of the circulation pump 18 and the heat pump unit 2 is started by the instruction of the control unit 16 and the water is heated from the upper part of the hot water storage tank 1. Then, it is determined whether or not the temperature detected by the fourth temperature sensor 4d has reached the boiling stop temperature T1 (for example, 70 ° C.) during the night time with respect to the boiling set temperature set by the remote controller 15 (step S10). When the temperature detected by the fourth temperature sensor 4d reaches the boiling stop temperature T1 (for example, 70 ° C.) during the nighttime period, the heating operation of the heat pump unit 2 is stopped (step S11).
For example, when the boiling set temperature of the remote controller 15 is 90 ° C., the boiling stop temperature T1 in the night time zone is 70 ° C. The boiling heating performance by the heat pump system is such that when the temperature of the water entering the heat pump unit 2 is low, the heating efficiency of the boiling is high, but when the temperature of the entering water is high, the heating efficiency of the boiling is reduced. Therefore, the boiling is stopped at a temperature lower than the boiling setting temperature.

In step S8, the control unit 16 sets the heating capacity of the heat pump unit 2 to be large, and operates with a maximum heating capacity of 6.0 KW.
That is, during the daytime period, the heating capacity of the heat pump unit 2 is set to the maximum, and the operation is performed to prevent the hot water from running out. In addition, since the daytime time zone has more sounds around the nighttime zone and the sound generated by the heat pump 2 does not bother much, there is no problem even if the heat pump unit 2 is operated with a maximum heating capacity of 6.0 KW. .

In step S12, it is determined whether or not the detected temperature of the first to third temperature sensors 4a to 4c has reached the boiling start temperature T2 in the daytime time zone. 18. The operation of the heat pump unit 2 starts and boils from the hot water storage tank 1 (step 13).
Here, in the case of the first embodiment, as shown in FIG. 3, in the heating operation in the daytime time zone, the boiling start temperature T2 or the temperature sensor that detects the boiling start temperature T2 varies depending on the time zone. It is That is, in the case of 7 o'clock to 9 o'clock, boiling is started when the temperature detected by the third temperature sensor 4c becomes 60 ° C. or lower, and in the case of 9 o'clock to 15 o'clock, the detection of the second temperature sensor 4b is started. When the temperature becomes 44 ° C. or lower, boiling is started. In the case of 15 to 17 o'clock, the boiling starts when the temperature detected by the third temperature sensor 4c becomes 44 ° C. or lower, and from 17:00 to 23:00 In this case, when the temperature detected by the second temperature sensor 4b becomes 44 ° C. or lower, boiling is started.

In step S14, it is determined whether or not the detected temperature of the first to fourth temperature sensors 4a to 4d has reached the boiling stop temperature T3 in the daytime period, and if it has reached, the heating operation of the heat pump unit 2 is stopped. (Step S15).
Here, in the case of the first embodiment, as shown in FIG. 3, even in the heating operation during the daytime period, the temperature sensor for detecting the boiling stop temperature T3 or the boiling stop temperature is varied depending on the time period. ing. That is, in the case of 7:00 to 9:00, the boiling is stopped when the detected temperature of the third temperature sensor 4c becomes 62 ° C. or higher, and in the case of 9:00 to 15:00, the detection of the third temperature sensor 4c is stopped. When the temperature reaches 46 ° C. or higher, the boiling is stopped. In the case of 15 to 17 o'clock, the boiling is stopped when the temperature detected by the fourth temperature sensor 4d becomes 46 ° C. or higher. In this case, when the temperature detected by the third temperature sensor 4c becomes 46 ° C. or higher, the boiling is stopped.

Since the heat pump type water heater shown in the first embodiment operates as described above, the heating capacity of the heat pump unit 2 is increased according to the outside air temperature and the amount of remaining hot water in the hot water storage tank 1 during the heating operation at nighttime. Variable, when the outside air temperature is low and the amount of remaining hot water is large, the heating capacity of the heat pump unit 2 is reduced to reduce the operating noise of the heat pump unit 2, and the outside air temperature during the daytime heating operation Even if hot water is used in a large amount of time in a short time by setting the heating capacity of the heat pump unit 2 to the maximum heating capacity regardless of the amount of remaining hot water in the hot water storage tank 1, Can be prevented.

It is a block diagram of the heat pump type water heater of Embodiment 1 of this invention. It is a flowchart which shows the control of Embodiment 1 of this invention. It is a table | surface which shows the relationship between the boiling start temperature of the daytime time slot | zone of Embodiment 1 of this invention, and a boiling stop temperature.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hot water storage tank 2 Heat pump unit 2c Outside temperature sensor 3 Heating circulation circuit 4a 1st temperature sensor 4b 2nd temperature sensor 4c 3rd temperature sensor 4d 4th temperature sensor 15 Remote control 16 Control part 18 Circulation pump

Claims (4)

In a heat pump type hot water heater that heats a liquid for hot water supply using a heat pump and stores the heated liquid in a hot water storage tank,
An outside air temperature detecting means for detecting the outside air temperature, a remaining hot water amount detecting means for detecting the remaining hot water amount in the hot water storage tank, and a heating capacity variable means for varying the heating capacity of the heat pump,
The heating capacity variable means varies the heating capacity of the heat pump in accordance with the outside air temperature and the amount of remaining hot water in the hot water storage tank during the boiling operation at night time, and the outside air temperature and the hot water storage during the daytime heating operation. A heat pump type hot water supply apparatus that operates by setting the heating capacity of the heat pump to a maximum heating capacity regardless of the amount of remaining hot water in the tank.   The heating capacity variable means is configured to provide a heating capacity of the heat pump when the outside air temperature is lower than a preset predetermined temperature and the amount of remaining hot water in the hot water storage tank is greater than a preset predetermined value at the time of heating operation at night time. The heat pump type hot water heater according to claim 1, wherein the heat pump type hot water heater is operated with a small value.   A plurality of the remaining hot water detection means are provided with a predetermined interval in the vertical direction of the hot water storage tank, and detect the amount of remaining hot water at the start of boiling and the stop of boiling according to the time of day during the heating operation during the daytime. The heat pump type water heater according to claim 1 or 2, wherein the temperature sensors are different.   A plurality of the remaining hot water detection means are provided with a predetermined interval in the vertical direction of the hot water storage tank, and detect the amount of remaining hot water at the start of boiling and the stop of boiling according to the time of day during the heating operation during the daytime. The heat pump type water heater according to claim 1 or 2, wherein the temperature sensor has a different set temperature.

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