JP2003156254A - Heat pump type water heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat pump type water heater requiring less power consumption by preventing the worse heating efficiency of a heat pump body to preclude the start of heating operation of the heat pump body in a daytime zone even in the case of a less amount of boiled water and a less amount of hot water supplied after completing boiling. SOLUTION: The heat pump type water heater comprises boiling starting residual hot water amount changing means 10a for preventing the worse heating efficiency of the heat pump body 12 by using a less amount of boiled water than the capacity of a hot water storage tank 2 and a less amount of boiled water with a high temperature water supplied to the heat pump body 12 and for changing the amount of a residual hot water at starting boiling after completing boiling in accordance with the amount of the boiled water in the storage tank 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to control of boiling operation of a heat pump type water heater.

[0002]

_2. Description of the Related Art Recently, a heat pump type water heater using a CO ₂ refrigerant is known. This water heater has the advantage that it can heat the boiling temperature to a high temperature of 90 ° C. or higher and has high heating efficiency, but the liquid supplied to the heat pump body that heats the liquid for hot water supply using the heat pump cycle As the temperature rises, the heating efficiency decreases.
Therefore, when the amount of hot water used is small, it is necessary to make the amount of boiling water smaller than the capacity of the hot water storage tank so as not to raise the temperature of the liquid supplied to the heat pump body.

On the other hand, if the boiling amount is reduced, the hot water tends to run out when the usage amount increases. Therefore, when the amount of remaining hot water in the hot water storage tank falls below a predetermined amount, it is necessary to start the boiling.

FIG. 3 is a block diagram of a conventional heat pump type water heater, FIG. 4 is a block diagram of a conventional heat pump body, and FIG. 5 is a flowchart of a conventional boiling control operation. In FIG. 3, 1 is a water heater main body, 2 is the main body 1
A hot water storage tank provided inside, 3 is a water supply pipe connected to the lower part of the hot water storage tank 2, 3a is a pressure reducing valve provided in the water supply pipe 3, and 4 is a hot water supply connected to the upper part of the hot water storage tank 2. Pipings, 4a are relief valves, 5 is a hot water supply pipe, and is a flow rate sensor for detecting the maximum or average hot water supply amount for one day or one week, and 6 is attached to the outer wall surface of the hot water storage tank 2. When the temperature sensor A for detecting the temperature of the water in the hot water storage tank 2 is attached to a position of a predetermined capacity on the outer wall surface of the hot water storage tank 2, the heat pump body 12 is used when the amount of hot water used is small.
The temperature for stopping the heating operation is detected, and the amount of remaining hot water in the hot water storage tank 2 is also detected from the detected temperature at the mounting position. 7a is also a temperature sensor B similar to the temperature sensor A6, which is attached to the upper portion of the hot water storage tank 2 as compared with the temperature sensor A6 and can detect a residual hot water amount smaller than that of the temperature sensor A6. Reference numeral 8 denotes a temperature sensor D that is attached to the lower pipe of the hot water storage tank 2 and detects the temperature for stopping the heating operation of the heat pump body 12 when the hot water storage tank 2 is completely boiled.

Reference numeral 9 replaces the heat generated in the heat cycle of the heat pump body 12 with the water in the hot water storage tank 2,
It is a circulation pump that circulates the water in the hot water storage tank 2 with the heat pump body 12 by a cold water pipe 12a and a hot water pipe 12b. Cold water pipe 12a connected to the bottom of the hot water storage tank 2
Further, water is supplied to the heat pump body 12 by the circulation pump 9, and the water heated by the heat pump body 12 is returned by the hot water pipe 12b connected to the upper portion of the hot water storage tank 2 to store hot water from the upper portion inside the hot water storage tank 2.

Reference numeral 10 denotes a controller for boiling water in the hot water storage tank 2, controlling the start / stop of operation of the heat pump body 12, and calculating the amount of hot water to be boiled based on the amount of hot water used per day. , The start and stop of the heating operation of the heat pump main body 12 and the operation of the circulation pump 9 are controlled based on the detected values of the temperature sensor B7a and the temperature sensor D8 and the input values from the operation unit 11 for setting the boiling temperature and the like. .

In FIG. 4, the heat pump cycle of the heat pump body 12 includes a compressor 13, a hot water heat exchanger 14,
Expansion valve 15, outdoor heat exchanger 16, accumulator 17
Are sequentially connected by a refrigerant pipe 12c.
Here, in order to absorb heat to the outdoor heat exchanger 16, the fan 18
Is attached, and the heat exchanger 14 for hot water supply exchanges heat between the high-pressure gas refrigerant discharged from the compressor 13 and the water for hot water supply. The refrigerant passage 14a through which the refrigerant flows and the water for hot water supply. It has a flowing hot water supply passage 14b.

Next, regarding the conventional boiling control operation,
This will be described with reference to the flowchart of FIG. First, when the boiling control is started (S1), the flow rate sensor 5 detects the maximum or average amount of hot water used for one day or one week in the control unit 10 (S2). A certain amount of hot water is used (eg 2
It is determined whether or not it is 50 L or more (S3), and a predetermined amount (250
L) or more, it is determined that the amount of hot water used is large, and the total amount (for example, 370 L) in the hot water storage tank 2 is boiled (S
4). If the amount is not more than the predetermined amount (250 L), it is determined that the amount of hot water used is small, and the amount of boiling water is set to 250 L to boil (S5).

Next, the temperature of the wall surface of the hot water storage tank 2 is detected by the temperature sensor B7a to determine whether or not the predetermined residual hot water amount for starting boiling is reached (S6). When the temperature sensor B7a becomes equal to or lower than a predetermined temperature, it is determined that the amount becomes equal to or lower than a predetermined remaining hot water amount (150 L) (S7), and the circulation pump 9 and the heat pump cycle are operated by the instruction of the control unit 10 to heat the heat pump main body 12 to a constant temperature. The heating operation is started with the capacity (for example, 4.5 KW) (S8), and the hot water is boiled from the upper portion of the hot water storage tank 2 at the boiling temperature T ° C. (for example 90 ° C.) set by the operation unit 11. When the entire amount (for example, 370L) in the hot water storage tank 2 is boiled (S4), when the temperature sensor D8 detects the predetermined temperature T ₁ (for example, 60 ° C.) (S9), the control unit 1
With the instruction of 0, the heating operation of the heat pump main body 12 is stopped (S10), and the boiling control is ended (S11). When the boiling water amount is 250 L (S5), the temperature sensor A6
Detects a predetermined temperature T ₁ (for example, 60 ° C.) (S
9) Then, the heating operation of the heat pump body 12 is stopped according to an instruction from the control unit 10 (S10), and the boiling control is ended (S11).

[0010]

In the conventional heat pump type hot water heater, the boiling amount is variable according to the amount of hot water used based on the detection value of the flow rate sensor 5, and when the amount of hot water used is small, for example, the temperature of the water to be supplied is high and the hot water storage tank. When the amount of hot water used in 2 is small and the amount of remaining hot water is large, when the next boiling is started in the heat pump body 12, when the entire amount of the hot water storage tank 2 is boiled, the amount of remaining hot water is large. The temperature of the liquid supplied to the water becomes high during the boiling process. When the water supply temperature becomes high, the heating efficiency decreases from the middle of boiling. Therefore, in order to reduce the amount of boiling water to be supplied at high temperature, the amount of boiling water should be made smaller than the capacity of the hot water storage tank 2 and the amount of boiling water to be supplied at high temperature. Is reduced to prevent the heating efficiency of the heat pump body 12 from being deteriorated. However, since the amount of remaining hot water at the start of boiling is always constant, if the amount of boiling water is reduced, the heating operation of the heat pump body 12 will start during the daytime only by supplying a small amount of hot water after completion of boiling. However, there was a problem that the electricity bill was high.

The present invention has been made in order to solve the above-mentioned problems, and in order to prevent deterioration of the heating efficiency of the heat pump body, even when the amount of boiling water is small,
It is an object of the present invention to provide a heat pump type water heater that can reduce the electricity bill by reducing the boiling during the daytime.

[0012]

A heat pump type water heater according to a first aspect of the present invention heats a liquid for hot water supply using a heat pump cycle, and heats the heated liquid to the upper part of a hot water storage tank of a water heater body. When the temperature of the liquid that has been stored more and returned to the heat pump body that is the heating source from the bottom of the hot water storage tank and returned to the hot water storage tank or the heat pump body reaches a preset temperature lower than the hot water storage temperature, the heating operation of the heat pump body is stopped and used. When the amount of boiling water in the hot water storage tank is changed based on the amount of hot water, and when the amount of remaining hot water in the hot water storage tank falls below a predetermined amount, the heat pump type water heater that starts the heating operation of the heat pump body is based on the amount of boiling water in the hot water storage tank. Then, a boiling start residual hot water amount changing means for changing the residual hot water amount at the start of boiling is provided.

Further, in the heat pump type hot water supply apparatus according to the present invention, the boiling start residual hot water amount changing means changes the residual hot water amount at the start of boiling to a small amount when the boiling hot water amount in the hot water storage tank is small. It is a thing.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. 1 is a configuration diagram of a heat pump type water heater showing Embodiment 1 of the present invention, FIG.
3 is a flowchart showing a boiling control operation according to Embodiment 1 of the present invention. The first embodiment of the present invention
Since the configuration diagram of the heat pump body 12 in FIG. 3 is the same as the conventional configuration shown in FIG. 4, the description thereof will be omitted.

The difference between the configuration diagram in the first embodiment of the present invention shown in FIG. 1 and the configuration diagram of the conventional heat pump type water heater shown in FIG. 3 is in the first embodiment of the present invention.
The configuration of the control unit 10 and the temperature sensor C7b are attached. That is, in the first embodiment of the present invention, the control unit 10 controls the boiling of water in the hot water storage tank 2 and the start / stop of the operation of the heat pump body 12, and also the boiling start residual hot water amount changing means 10a. And also
The temperature sensor C7b is attached to the upper portion of the hot water storage tank 2 as compared with the temperature sensor B7a, and can detect a residual hot water amount smaller than that of the temperature sensor B7a.

The boiling control operation of the heat pump water heater according to the first embodiment will be described with reference to the flowchart of FIG. The description of the same or corresponding parts as those of the conventional example will be omitted.

First, when the boiling control is started (S
1) The controller 10 detects the maximum or average amount of hot water used for one day or one week by the flow rate sensor 5 (S2). It is determined whether or not the amount of hot water used is equal to or greater than a predetermined amount (for example, 250 L) (S3).
Boil L) (S4). The temperature sensor B7a detects the temperature of the wall surface of the hot water storage tank 2 to determine whether or not the amount of remaining hot water has reached the start of boiling (S6). When the temperature sensor B7a falls below a predetermined temperature, it is determined that the remaining hot water amount (150 L) has fallen below (S7), and the circulating pump 9 and the heat pump main body 12 have a constant heating capacity (for example, 4.
The heating operation is started at 5 KW (S8), and the hot water is boiled from the upper part of the hot water storage tank 2 at the boiling temperature T ° C. (for example, 90 ° C.) set by the operation unit 11. And the temperature sensor D8
Detects a predetermined temperature T ₁ (for example, 60 ° C.) (S
9) Then, the heating operation of the heat pump body 12 is stopped according to an instruction from the control unit 10 (S10), and the boiling control is ended (S11).

On the other hand, if the amount of hot water used is equal to or less than the predetermined amount (250 L) (S3), it is judged that the amount of hot water used is small, and the boiling water amount is set to 250 L and the water is boiled (S5). Whether or not the amount of remaining hot water for starting boiling has reached a predetermined value, temperature sensor C7
The temperature of the wall surface of the hot water storage tank 2 is detected in b (S12). When the temperature sensor C7b falls below a predetermined temperature, it is determined that the remaining hot water amount (75L) has dropped below a predetermined level (S13), and the control unit 1
With the instruction of 0, the circulation pump 9 and the heat pump main body 12 start the heating operation with a constant heating capacity (for example, 4.5 KW) (S8), and the boiling temperature T ° C. set by the operation unit 11 from the upper portion of the hot water storage tank 2 is started. Boiling water is heated (for example, 90 ° C.) (S14). Since the amount of boiling water is 250 L, when the temperature sensor A6 attached to the outer wall surface of the hot water storage tank 2 detects a predetermined temperature T ₁ (for example, 60 ° C.) (S
15) Then, the heating operation of the heat pump body 12 is stopped according to an instruction from the control unit 10 (S10), and the boiling control is ended (S11). Thus, when the amount of hot water used is 250 L or less (S3), the amount of remaining hot water at the start of boiling is changed from 150 L or less (S7) to 75 L or less (S13).

Therefore, according to the first embodiment, even when the amount of boiling water is reduced to prevent deterioration of heating efficiency, the amount of residual hot water at the start of boiling is reduced from 150 L or less (S7) to 75 L or less (S13). Since it has been changed, when the amount of boiling water is reduced, the heating operation of the heat pump body 12 will not start during the daytime hours by only supplying a small amount of hot water after boiling is completed. Boil up less and electricity cost can be reduced.

[0020]

As described above, according to the heat pump type water heater of claim 1 of the present invention, the boiling water amount is high in the summer when the temperature of the water to be supplied is high and the amount of hot water used in the hot water tank is small and the amount of remaining hot water is large. Since the heat pump body can reduce the boiling of hot water by making it smaller than the capacity of the hot water storage tank, the deterioration of heating efficiency can be prevented, and even when the boiling water volume is reduced, the boiling start remaining hot water volume can be changed. Therefore, after the boiling is completed, even if a small amount of hot water is supplied, the heating operation of the heat pump body is not started during the daytime, and the effect of reducing the electricity bill can be obtained.

Further, according to the water heater of claim 2, the amount of boiling start remaining hot water is reduced even when the amount of boiling water is reduced, so even if a small amount of hot water is supplied after the completion of boiling, it will be in the daytime hours. It is possible to reliably reduce the electricity bill without starting the heating operation of the heating device.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a heat pump type water heater showing a first embodiment of the present invention.

FIG. 2 is a flowchart of a boiling control operation according to the first embodiment of the present invention.

FIG. 3 is a configuration diagram of a conventional heat pump water heater.

FIG. 4 is a configuration diagram of a conventional heat pump body.

FIG. 5 is a flowchart of a conventional boiling control operation of the water heater.

[Explanation of symbols]

1 water heater main body, 2 hot water storage tank, 5 flow rate sensor, 6
Temperature sensor A, 7a Temperature sensor B, 7b Temperature sensor C, 10 Control unit, 10a Boiling start residual hot water amount changing means, 12 Heat pump body.

Claims (2)

[Claims] 1. A heat pump cycle is used to heat a liquid for hot water supply, the heated liquid is stored from an upper part of a hot water storage tank of a water heater main body, and returned from a lower part of the hot water storage tank to a heat pump main body serving as a heating source, or a hot water storage tank or When the temperature of the liquid returned to the heat pump main body becomes lower than the hot water storage temperature, the heating operation of the heat pump main body is stopped, and the boiling water amount of the hot water storage tank is changed based on the amount of hot water used. When the amount of remaining hot water becomes equal to or less than a predetermined amount, in the heat pump type water heater that starts the heating operation of the heat pump body, based on the amount of boiling water in the hot water storage tank, the boiling start remaining hot water amount changing means for changing the amount of remaining hot water to start boiling is provided. A heat pump type water heater characterized by being equipped. 2. The boiling start residual hot water amount changing means changes the residual hot water amount at the start of boiling to a small amount when the boiling hot water amount in the hot water storage tank is small.
Heat pump water heater described.