JP2009063262A - Heat pump type water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To resolve a problem in a conventional heat pump type water heater wherein, if heating capacity is reduced when a remaining hot water amount is large even at night, and a large amount of hot water is used in a short time, heating capacity of boiling water becomes insufficient, and hot water becomes short. <P>SOLUTION: In the heat pump type water heater heating liquid for hot water supply by using a heat pump unit 2, and storing the heated liquid in a hot water storage tank 1, a control part 16 is provided, varying the heating capacity of the heat pump unit 2 in response to the residual hot water amount in the hot water storage tank 1 when carrying out boiling at night, and maximizing the heating capacity of the heat pump unit 2 irrespective of the residual hot water amount in the hot water storage tank 1 when carrying out boiling in the day time. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a heat pump type water heater.

  Conventional heat pump type water heaters are equipped with heating capacity variable means that varies the heating capacity of the heat pump cycle 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, if the heating capacity is reduced when the amount of remaining hot water is large even during daytime hours, the heating capacity to boil the hot water when a large amount of hot water is used in a short time However, there was a problem of running out of hot water.

  The present invention has been made to solve the above-described problems, and during the nighttime period, the operation sound of the heat pump unit is reduced according to the amount of remaining hot water in the hot water storage tank, and during the daytime period, the amount of remaining hot water is The purpose is to provide a heat pump type water heater that can prevent hot water from running out even when a large amount of hot water is used in a short time by operating the heating capacity of the heat pump unit at the maximum heating capacity. And

The heat pump type hot water heater according to the present invention is a heat pump type hot water heater that heats a liquid for hot water supply using a heat pump unit, and stores the heated liquid in a hot water storage tank.
The heating capacity of the heat pump unit is varied according to the amount of remaining hot water in the hot water storage tank at the time of boiling operation during night time, and the heat pump is independent of the amount of hot water in the hot water storage tank 1 at the time of boiling operation during daytime. It is characterized by comprising a control unit for controlling the heating capacity of the unit to operate at the maximum heating capacity.

  According to the heat pump type water heater according to the present invention, the heating capacity of the heat pump unit is varied according to the amount of remaining hot water in the hot water storage tank at the time of boiling during night time, and the heating capacity of the heat pump unit is increased when the amount of remaining hot water is large. The heating capacity is reduced to reduce the operation sound of the heat pump unit, and the heating capacity of the heat pump unit is operated at the maximum heating capacity regardless of the amount of remaining hot water in the hot water storage tank 1 when boiling in the daytime. Can prevent running out of hot water

Embodiment 1 FIG.
FIG. 1 is a block diagram of a heat pump type water heater according to the first embodiment of the present invention, FIG. 2 is a flowchart of control according to the first embodiment of the present invention, and FIG. 3 is a boiling start temperature and a boiling stop in the daytime period. It is a table | surface which shows the relationship of temperature.
In FIG. 1, a hot water storage tank 1 stores water and hot water, and in a heat pump unit 2 as a heating means, a compressor, a hot water supply heat exchanger, an expansion valve, an outdoor heat exchanger, and an accumulator are sequentially connected by refrigerant piping. A cycle circuit is provided.
A heating circulation circuit 3 is connected to the heat pump unit 2, and the heating circulation circuit 3 is connected to the upper and lower parts of the hot water storage tank 1. The heating circulation circuit 3 is provided with a circulation pump 18 for guiding water from the lower part of the hot water storage tank 1 to the heat pump unit 2, exchanging heat with the outside air by a heat pump cycle, boiling water into high temperature hot water, It is returned to the top of 1.
A fourth boiling temperature sensor 4d is provided on the lower side of the hot water storage tank 1 of the heating circuit 3, and together with the first to third boiling temperature sensors 4a to 4c provided on the outer periphery of the hot water storage tank 1. The boiling state of water in the hot water storage tank 1 is detected. The hot water tank temperature sensor 5 detects the temperature of the upper part of the hot water 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.
The water supply pipe 9 is connected to a water source such as a water pipe, and the pressure reducing valve 11 is attached to the water supply pipe 9 and connected to the lower part of the hot water storage tank 1 via the 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. 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 boiling temperature sensors 4a to 4d, a hot water storage tank temperature sensor 5, a hot water supply temperature sensor 14, and water flow detection. While receiving the signal from the means 13, the heat pump unit 2, the electric hot / cold water mixing valve 6 and the like are controlled.

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 7 passes through the pressure reducing valve 9, 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 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 temperature set by the remote controller 15 (for example, 90 The temperature is raised so that the temperature of the hot water storage tank 1 is increased (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 of the fourth boiling temperature sensor 4d becomes equal to or higher than a certain temperature (for example, 70 ° C.), the boiling by the heat pump unit 2 is determined to be complete when the hot water storage tank 1 has been heated. At this time, the boiling heating performance 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 low when the temperature of the entering water is high. Have the characteristics to The hot water in the hot water storage tank 1 expanded by the hot water storage is discharged from the relief valve 10. Further, when the hot water in the hot water storage tank 1 is reduced due to the hot water supply, reheating is performed by the detected temperatures of the first to third boiling temperature sensors 4a to 4c.
For example, the temperature detected by the second boiling temperature sensor 4b in the middle position of the hot water storage tank 1 between 17:00 and 23:00, which requires a large amount of hot water, such as preparation for dinner and hot water in the bath, is 44 ° C. or lower. When the temperature becomes, re-boiling is performed, and when the temperature detected by the third boiling temperature sensor 4c becomes 46 ° C. or higher, the re-boiling is stopped.

  When the faucet or the like is opened to supply hot water, the hot water and water source water stored in the hot water storage tank 1 pass through the hot water supply pipe 7 and the water supply bypass pipe 8 to the electric hot water mixing valve 6, respectively. The mixing ratio of hot water and water in the electric hot / cold water mixing valve 6 is controlled so that the temperature detected by the hot water supply temperature sensor 14 attached to the temperature becomes the 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 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 in step 2 whether or not it is a night time zone. If it is a night time zone, the process proceeds to step S3, and if not, the process proceeds to step S7. Here, the night time zone is from 23:00 to 7:00.

  Step S3 detects the amount of remaining hot water in the hot water storage tank 1 from the detected temperatures of the first to fourth boiling temperature sensors 4a to 4d.

  In step S4, the control unit 16 determines whether or not the remaining hot water amount in the hot water storage tank 1 is 150L or less. If it is 150L or less, the process proceeds to step S5, and if not, the process proceeds to step S6.

In step S5, 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 7.2 KW. In step S6, the control unit 16 sets the heating capacity of the heat pump unit 2 to be small, It operates with a heating capacity of 6.0 KW.
The operation sound of the heat pump unit 2 is 44 dB when operating at a maximum heating capacity of 7.2 KW and 42 dB when operating at a heating capacity of 6.0 KW.

Step S8 starts the heating operation of the circulation pump 18 and the heat pump unit 2 in accordance with an instruction from the control unit 16 and raises the water from the upper part of the hot water storage tank 1. Then, it is determined whether or not the temperature detected by the fourth boiling temperature sensor 4d has reached the boiling stop temperature T1 (for example, 70 ° C.) in the night time zone with respect to the boiling temperature set by the remote controller 15 (step S1). S9) When the temperature detected by the fourth boiling 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 S10).
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 S <b> 7, the controller 16 sets the heating capacity of the heat pump unit 2 to a large value and operates at a maximum heating capacity of 7.2 KW.
That is, during the daytime hours, the heating capacity of the heat pump unit is operated at the maximum to prevent the hot water from running out. In addition, since there are fewer complaints of operation sound in the daytime period than in the nighttime period, there is no problem even if the heat pump unit 2 is operated with the maximum heating capacity of 7.2 KW.

In step S11, it is determined whether or not the temperature detected by the first to third boiling temperature sensors 4a to 4c has reached the boiling start temperature T2 in the daytime time zone. Then, the circulation pump 18 and the heat pump unit 2 start to operate and boil from the upper part of the hot water storage tank 1 (step 12).
For example, as shown in FIG. 3, the boiling start temperature T2 in the daytime period varies depending on the time period, and the boiling temperature sensor for detecting the temperature also varies. In the case of 7:00 to 9:00, the boiling starts when the temperature detected by the third boiling temperature sensor 4c becomes 60 ° C. or lower, and in the case of 9:00 to 15:00, the second boiling temperature is started. When the temperature detected by the sensor 4b becomes 44 ° C or lower, boiling is started. In the case of 15 to 17 o'clock, when the temperature detected by the third boiling temperature sensor 4c becomes 44 ° C or lower, boiling is started. In the case of 17:00 to 23:00, when the temperature detected by the second boiling temperature sensor 4b becomes 44 ° C. or lower, the boiling is started.

In step S13, it is determined whether or not the detected temperatures of the first to fourth boiling temperature sensors 4a to 4d have reached the boiling stop temperature T3 in the daytime period. If the temperature has reached, the heating of the heat pump unit 2 is determined. The operation is stopped (step S14).
For example, as shown in FIG. 3, the boiling stop temperature T3 in the daytime time zone is also different depending on the time zone, and the boiling temperature sensor for detecting the temperature is also different. That is, in the case of 7:00 to 9:00, the boiling is stopped when the temperature detected by the third boiling temperature sensor 4c becomes 62 ° C. or more, and in the case of 9:00 to 15:00, the third boiling is stopped. When the temperature detected by the temperature sensor 4c is 46 ° C or higher, the boiling is stopped. In the case of 15 to 17 o'clock, the temperature is increased when the temperature detected by the fourth temperature sensor 4d is 46 ° C or higher. In the case of 17:00 to 23:00, when the temperature detected by the third boiling temperature sensor 4c reaches 46 ° C. or higher, the boiling is stopped.

Since the heat pump type hot water heater shown in the first embodiment operates as described above, the heating capacity of the heat pump cycle is varied according to the amount of remaining hot water in the hot water storage tank at the time of boiling in the night time, and the amount of remaining hot water When there is a large amount of heat, the heating capacity of the heat pump cycle is reduced to reduce the operation sound of the heat pump cycle, and the heat pump cycle is heated regardless of the amount of remaining hot water in the hot water storage tank 1 during boiling during daytime hours. By operating at the maximum heating capacity, it is possible to prevent running out of hot water even when hot water is used in a large amount for a short time.

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 3 Heating circulation circuit 4a-4d Temperature sensor 15 for boiling of 1st-4th Remote control 16 Control part 10 Circulation pump

Claims (3)

In a heat pump type hot water heater that heats a hot water supply liquid using a heat pump unit and stores the heated liquid in a hot water storage tank,
The heating capacity of the heat pump unit is varied according to the amount of remaining hot water in the hot water storage tank at the time of boiling operation during night time, and the heat pump is independent of the amount of hot water in the hot water storage tank 1 at the time of boiling operation during daytime. A heat pump type hot water heater comprising a control unit for controlling the heating capacity of the unit to operate at the maximum heating capacity.   The controller is configured to control the heating capacity of the heat pump unit to be set to a small value when the amount of remaining hot water in the hot water storage tank is larger than a predetermined value during the heating operation at night time. The heat pump type water heater according to claim 1.   The controller is configured to detect a temperature sensor that detects a boiling start temperature and a boiling stop temperature, or a temperature sensor that detects a boiling start temperature and a boiling stop temperature, depending on the time of day, during boiling operation during daytime. The heat pump type hot water heater according to claim 1 or 2, wherein the temperature is different.

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