JP2713084B2 - Heat pump water heater - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat pump hot water supply apparatus of a hot water storage type.

[0002]

2. Description of the Related Art Conventionally, this type of heat pump hot water supply apparatus has a configuration as disclosed in Japanese Patent Application Laid-Open No. 60-164157. Hereinafter, the configuration will be described with reference to FIGS.

As shown in the figure, a compressor 1, a heat exchanger 2 for hot water, a throttle mechanism 3, an evaporator 4, and an accumulator 5 are connected by an annular refrigerant line to constitute a heat pump cycle.

In addition, a water supply circuit 8 extending from the lowermost part of the hot water storage tank 6 to the hot water heat exchanger 2 via the pump 7, and a hot water storage tank 6 downstream of the hot water heat exchanger 2 via an auxiliary heater 9. The heat pump cycle and the hot water storage tank 6 are connected by a tapping circuit 10 which reaches the hot water supply circuit.

[0005] Reference numeral 11 denotes a water temperature detector for detecting the temperature of the water in the water supply circuit 8.
It has a set value, issues a signal for stopping the operation of the heat pump according to the first set value, and issues a signal for stopping the operation of the auxiliary heater 9 according to the second set value. Reference numeral 12 denotes a hot water temperature detector flowing into the hot water storage tank 6, which controls the number of rotations of the pump 7 to control the amount of circulating water.
The hot water inflow temperature into the hot water tank 6 during the operation is kept constant, and the hot water is sequentially stored from the upper portion of the hot water tank 6. 13 is a blower, 14 is a water supply pipe provided in the hot water storage tank 6, and 15 is a hot water supply pipe.

The operation of the above configuration will be described.
When the detected temperature of the water temperature detector 11 is equal to or lower than the first set value at the time of the high outside air temperature, the hot water temperature detector 12 sequentially stores hot water of a constant temperature from the upper part of the hot water storage tank 6 by the heat pump alone operation in which the auxiliary heater 9 does not operate. . Hot water and hot water tank 6 stored at this time
A temperature boundary layer is formed between the lower temperature water and the lower temperature water. When the boundary layer reaches the water supply circuit 8 and the temperature detected by the water temperature detector 11 exceeds a first set value, the operation of the heat pump is stopped and the auxiliary heater 9 is stopped. Is driven. Thereafter, when the temperature detected by the water temperature detector 11 reaches the second set value, the auxiliary heater 9 stops.
If there is residual hot water in the hot water storage tank 6, the temperature boundary layer is
, The operation time of the heat pump is short, and the operation of the auxiliary heater 9 is long.

At a low outside air temperature, the heat pump and the auxiliary heater 9 operate simultaneously, and when the temperature detected by the water temperature detector 11 exceeds a first set value, the heat pump operation is stopped, and the temperature detected by the water temperature detector 11 is reduced. When the second set value is reached, the auxiliary heater 9 stops. As described above, uniform high-temperature hot water is ensured up to the lowermost portion in the hot water storage tank 6.

[0008]

However, according to the above-mentioned conventional structure, as shown in FIG. 4, during the operation of the heat pump, the temperature boundary layer in the hot water tank 6 reaches the water supply circuit 8 and the water temperature detector 11 sensing the temperature becomes the first set value above T ₁ stops heat-pump operation, the auxiliary heater 9 is operated. At this time, when hot water is supplied from hot water supply pipe 15, water supply pipe 1
4, cold water flows into hot water storage tank 6, so that water temperature detector 11
The detected temperature is a first set value T ₁ follows becomes supplemental heater 9 is OFF, but the heat pump operation is started, the heat capacity of the auxiliary heater 9 and the hot water temperature rise of the heat pump leaves late from the hot water heat exchanger 2 Since the rise is slow, the tapping temperature Tout detected by the hot water temperature detector 12 repeats hunting. Accordingly, the fluctuation of the flow rate of the pump 8 becomes large, and it becomes difficult to control the temperature of the hot water flowing into the hot water storage tank 6 to be constant.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to secure controllability of the temperature of hot water flowing into a hot water storage tank and reliability of the apparatus.

[0010]

According to the present invention, a first hot water temperature detector is provided in a first tapping circuit extending from a downstream side of a hot water heat exchanger to an auxiliary heater. A second hot water temperature detector is provided in a second tapping circuit extending from the outlet to the top of the hot water tank.
The controller is provided with a controller for selectively using the second hot water temperature detector when the hot water temperature detector, the heat pump, the auxiliary heater are operated in combination, and when the auxiliary heater is operated alone.

[0011]

According to the present invention, when the heat pump is operated, the hot water temperature is controlled by the first hot water temperature detector, the temperature boundary layer in the hot water tank reaches the water supply circuit, and the detected temperature of the water temperature detector rises. When the first set value is reached, the heat pump is stopped, the auxiliary heater is turned on, and the temperature of the hot water is controlled by the second hot water temperature detector. At the same time, by controlling the hot water temperature by the first hot water temperature detector, the heat capacity of the auxiliary heater and the hunting of the tap water temperature caused by the slow rise of the hot water temperature from the hot water heat exchanger when the heat pump starts up are prevented, Hot water of a certain temperature flows into the hot water storage tank.

[0012]

An embodiment of the present invention will be described below with reference to FIG.

In FIG. 1, the same reference numerals as those in FIG. 3 denote the same members, and have the same functions. Therefore, detailed description will be omitted, and different points will be mainly described.

In FIG. 1, reference numeral 16 denotes a first tapping circuit extending from the outlet of the heat exchanger for hot water to the inlet of the auxiliary heater 9;
It is a first hot water temperature detector provided therein. Reference numeral 18 denotes a second hot water outlet circuit extending from the outlet of the auxiliary heater 9 to the upper portion of the hot water storage tank 6, and 19 denotes a second hot water temperature detector provided in the circuit 18. 20
Is a controller that controls the auxiliary heater 9, the pump 7, and the compressor 1 in accordance with signals from the water temperature detector 11, the first and second hot water temperature detectors 17, 19, as described later.

The operation of the above configuration will be described with reference to the control flow of FIG. First, the single operation of the heat pump will be described. In FIG. 2, when the device is turned on (S1), first, the pump 7 is turned on (S2), and the compressor 1 is turned on.
(S3).

Thus, the water in the hot water storage tank 6 is heated by the pump 7 through the water supply circuit 8 and is heated by the heat exchanger 2 for hot water by the heat of condensation of the heat pump, and is sequentially stored from the upper part of the hot water storage tank 6. Here, the first hot water temperature detector 17 detects the hot water temperature Tout at the outlet of the hot water heat exchanger 2 (S4), and controls the rotation speed of the pump 7 so that Tout becomes equal to the set value TA. (S5, S6) Next, the water temperature T of the water supply circuit 8 is detected by the water temperature detector 11 (S7). If the first set value T ₁ > T, the control of the pump 7 is continued, and conversely, T ₁ < If T, it is determined that the temperature boundary layer in the hot water tank 6 has reached the water supply circuit 8 (S8), the compressor 1 is turned off (S9), and the heat pump operation is stopped. At the same time, the hot water temperature detection is changed from the first hot water temperature detector 17 to the second hot water temperature detector 19 (S1).
0), the auxiliary heater 9 is turned on (S11), the hot water temperature Tout at the outlet of the auxiliary heater 9 is detected by the second hot water temperature detector 19 (S12), and the pump is set so that Tout becomes equal to the set value TA. 7 is controlled (S13, S14).

Next, the water temperature T of the water supply circuit 8 is detected by the water temperature detector 11.
Is detected (S15), and the second set value T _TwoAnd T.
(S16) T_TwoIf <T, uniform down to bottom of hot water tank 6
The auxiliary heater 9 is turned off (S1
7), the pump 7 is turned off (S18).

Conversely, if T ₂ > T, the first set value T ₁ > again
T or determined (S9), T ₁ is turned OFF auxiliary heater 9 from the T <continued control of the pump 7 returns to S12 if T, T ₁ is the case where it is tapped from the hot water supply pipe 15> (S
20) At the same time, the hot water temperature is detected by the second hot water temperature detector 19.
Is replaced with the first hot water temperature detector 17 (S21), and the process returns to S3 to start the heat pump operation. When the heat pump and the auxiliary heater 9 are simultaneously operated, the conventional hot water temperature control is performed only by the second hot water temperature detector 19. The above operation is performed by the controller 20.

According to the configuration of this embodiment, during the heat pump operation, the hot water temperature is controlled by the first hot water temperature detector 17, the temperature boundary layer in the hot water storage tank 6 reaches the water supply circuit 8, and the water temperature detector 11 Rises in the first set value T
_{When the} temperature reaches ₁ , the heat pump is stopped, the auxiliary heater 9 is turned on, the hot water temperature is controlled by the second hot water temperature detector 19, and the temperature detected by the water temperature detector 11 decreases due to hot water and the operation is switched to the heat pump operation. At the same time, the first hot water temperature detector 17 controls the hot water temperature. This prevents hunting of the tap water temperature caused by a slow rise in the heat capacity of the auxiliary heater 9 and the temperature of the hot water flowing out of the hot water heat exchanger 2 when the heat pump rises, and allows hot water of a constant temperature to flow into the hot water storage tank 6. Can improve the reliability of the pump.

[0020]

As described in the above embodiment, the heat pump hot water supply apparatus of the present invention includes a first temperature detector in the first tapping circuit extending from the downstream side of the hot water heat exchanger to the auxiliary heater, and the auxiliary heater. A second hot water temperature detector is provided in the second hot water circuit from the hot water outlet to the top of the hot water tank. When the heat pump is operated alone, the first hot water temperature detector, heat pump, auxiliary heater are used together, and the auxiliary heater is operated alone At the time, a controller for selecting and using the second hot water detector is provided.
The hot water temperature is controlled by the hot water temperature detector, the temperature boundary layer in the hot water tank reaches the water supply circuit, the detected temperature of the water temperature detector rises, and when the temperature reaches the first set value, the heat pump is stopped and the auxiliary heating is performed. When the heater is turned on and the hot water temperature is controlled by the second hot water temperature detector, the temperature detected by the water temperature detector drops due to hot water and the like, and the operation is switched to the heat pump operation.
The hot water temperature is controlled by a hot water temperature detector.

This prevents the heat capacity of the auxiliary heater at the time of switching from the auxiliary heater operation to the heat pump operation and the hunting of the tap water temperature caused by the slow rise of the hot water temperature from the hot water heat exchanger. Hot water at a constant temperature can flow into the inside, and the reliability of the pump is also improved.

[Brief description of the drawings]

FIG. 1 is a circuit configuration diagram of a heat pump water heater according to one embodiment of the present invention.

FIG. 2 is a control flowchart of FIG. 1;

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

FIG. 4 is a characteristic diagram showing a relationship between time, water temperature, and water flow rate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 2 Heat exchanger for hot water 3 Throttle mechanism 4 Evaporator 6 Hot water tank 7 Pump 8 Water supply circuit 9 Auxiliary heater 11 Water temperature detector 16 1st tapping circuit 17 1st hot water temperature detector 18 2nd tapping circuit 19th 2 Hot water temperature detector 20 Controller

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-211359 (JP, A) JP-A-5-312405 (JP, A) JP-B-2-60950 (JP, B2)

Claims (1)

(57) [Claims] 1. A heat pump in which a compressor, a heat exchanger for hot water, a throttle mechanism, and an evaporator are connected by an annular refrigerant pipe, and water supply from the lowermost part of the hot water storage tank to the heat exchanger for hot water via the pump. Circuit, a water temperature detector in the water supply circuit, a first hot water circuit from a downstream side of the hot water heat exchanger to an auxiliary heater, a first hot water temperature detector in the first hot water circuit, and the auxiliary heater A second tapping circuit extending from the outlet to the top of the hot water tank;
The hot water supply circuit includes a second hot water temperature detector and a controller. The controller performs the operation and stop of the heat pump and the operation and stop of the auxiliary heater according to the temperature detected by the water temperature detector. (1) A heat pump hot water supply device which performs control for selecting and using the second hot water temperature detector when the combined use of the hot water temperature detector, the heat pump, and the auxiliary heater is performed and the auxiliary heater is operated alone.