JP3855795B2 - Heat pump water heater - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a heat pump water heater.
[0002]
[Prior art]
Conventionally, this type of heat pump water heater includes, for example, those disclosed in JP-A-60-221661, JP-A-9-68369, and JP-A-2001-201177. FIG. 6 shows a conventional heat pump water heater described in JP-A-60-221661.
[0003]
In FIG. 6, a heat pump circuit 5 comprising a compressor 1, a heat exchanger 2, a pressure reducing device 3, an evaporator 4 and a circulation pump 6 for sending water from a hot water tank 7 to the heat exchanger 2, a power converter 8 for the compressor 1, and outside air A temperature sensor 9, a heat exchanger inlet water temperature sensor 10, a feed water temperature sensor 11, a rotation speed detector 12, and a calculation control device 13 are provided. The calculation control device 13 receives a signal from each sensor, and supplies a hot water supply load and required heating capacity. Then, the heating capacity, power consumption, and efficiency are calculated, the minimum rotation speed at which the heating capacity is equal to the required heating capacity is obtained, and the optimum compressor rotation speed at which the efficiency is maximum at the minimum rotation speed or more is determined. The optimum rotational speed is maintained by the rotational speed detector 12 and the arithmetic control device 13 via the power conversion device 8. As described above, Japanese Patent Laid-Open No. 60-221661 sets the rotational speed of the compressor based on the outside air temperature and the feed water temperature. Japanese Patent Laid-Open No. 9-68369 (not shown) obtains the required heating amount from the amount of remaining hot water in the hot water tank and sets the rotation speed of the compressor. Japanese Patent Laid-Open No. 2001-201177 (not shown) sets the rotational speed of the compressor based on both the outside air temperature and the time zone.
[0004]
[Problems to be solved by the invention]
However, in each of the above conventional examples, the setting of the rotational speed of the compressor is intended to obtain the required heating capacity, and there is a problem that it cannot always be operated at the highest efficiency.
[0005]
This invention solves the said conventional subject, and it aims at providing the heat pump water heater with a high energy-saving effect by always operating at the highest efficiency.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, the present invention provides a heat pump that connects a compressor, a radiator, a decompressor, and an evaporator to form a refrigerant circuit, a hot water storage tank, and a water circulation path that communicates the lower and upper parts of the hot water storage tank. A circulation means provided in the water circuit, a water circulation circuit connected to the water heat exchanger for exchanging heat with the radiator, a hot water temperature setting means for setting the boiling water temperature to be stored in the hot water storage tank, and an outside air temperature detection means . a preset for a signal from a transmitter has been set signal and the outside air temperature detection means by the hot water temperature setting means regardless of the medium temperature detected temperature detector provided on the outlet side of the water exchanger The compressor is operated at the set number of revolutions, and the heat pump water heater is configured to control the circulation means so that the hot water stored in the hot water storage tank becomes the hot water temperature set by the hot water temperature setting means.
[0007]
As a result, the rotational speed at which the maximum efficiency can be obtained is obtained and set with respect to the boiling set temperature, so that it is always possible to operate at the maximum efficiency and to save energy.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
The invention according to claim 1 is provided in a heat pump that connects a compressor, a radiator, a decompressor, and an evaporator to form a refrigerant circuit, a hot water storage tank, and a water circulation path that communicates the lower and upper portions of the hot water storage tank. A circulation circuit, a water circulation circuit connected to a water heat exchanger for exchanging heat with the radiator, a hot water temperature setting means for setting boiling water temperature to be stored in the hot water storage tank, and an outside air temperature detection means. Regardless of the medium temperature detected by the temperature detector provided on the outlet side of the water exchanger, the setting signal transmitted by the hot water temperature setting means and the signal from the outside air temperature detection means are set in advance. The compressor is operated at the number of revolutions, and the heat pump water heater is configured to control the circulation means so that the hot water stored in the hot water storage tank becomes the hot water temperature set by the hot water temperature setting means.
[0009]
As a result, the rotational speed at which the highest efficiency can be obtained is obtained and set with respect to the outside air temperature and the boiling set temperature, so that the engine is always operated at the highest efficiency, thereby saving energy.
[0010]
【Example】
Embodiments of the present invention will be described below with reference to the drawings. In addition, in a prior art example and each Example, the same code | symbol is attached | subjected about what has the same structure and the same operation | movement, and description is partially abbreviate | omitted.
[0011]
Example 1
FIG. 1 is a diagram illustrating the configuration of the heat pump water heater in the first embodiment of the present invention, FIG. 2 is a diagram illustrating the efficiency and heating capacity with respect to the rotational speed of the compressor of the heat pump water heater, and FIG. 3 is the heat pump water heater. It is explanatory drawing which shows the rotation speed with respect to the boiling temperature of a machine, heating capability, and required heating capability. In FIG. 1, 1 is a compressor, 2 is a radiator, 3 is a decompression device, 4 is an evaporator, and the compressor 1, the radiator 2, the decompression device 3, and the evaporator 4 are sequentially connected, A refrigerant circuit of the heat pump 5 is configured. 6 is a circulation pump (circulation means), 7 is a hot water storage tank, 14 is a water heat exchanger for exchanging heat with the radiator 2, and the circulation pump 6 and the water heat exchanger 14 are below and above the hot water tank 7. A water circulation path that communicates with each other is constructed. A temperature detector 15 is provided at the outlet of the water heat exchanger 14 and detects a medium temperature to generate a signal. Reference numeral 16 denotes hot water temperature setting means, which sets the boiling hot water temperature automatically or manually. A circulation amount control unit 17 controls the rotational speed of the circulation pump 6 so that the signal from the temperature detector 15 matches the signal from the hot water temperature setting means 16. Reference numeral 18 denotes a rotation speed setting means for setting the rotation speed of the compressor 1 based on a signal from the hot water temperature setting means 16. A compressor control unit 19 receives a signal from the rotation speed setting means 18 and operates the compressor 1 at the set rotation speed.
[0012]
About the heat pump water heater comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.
[0013]
When the boiling temperature is set automatically or manually by the hot water temperature setting means 16, the setting signal is transmitted regardless of the medium temperature detected by the temperature detector 15 provided on the outlet side of the water exchanger 14. The rotational speed setting means 18 receives the transmitted setting signal, selects the rotational speed at which the highest efficiency is preset with respect to the boiling set temperature, and selects the rotational speed to be the selected rotational speed. The compressor 19 is operated by the control unit 19. Then, the high-temperature and high-pressure superheated gas refrigerant discharged from the compressor 1 flows into the heat exchanger 2 where the water sent from the circulation pump 6 and flowing into the water heat exchanger 14 is heated. At that time, the heat-cooled refrigerant flows into the decompression device 3, where the refrigerant is decompressed and flows into the evaporator 4. Then, it absorbs atmospheric heat to evaporate and returns to the compressor 1. On the other hand, the water flowing into the water heat exchanger 14 from the lower part of the hot water tank 7 by the circulation pump 6 is heated by the heat of the refrigerant, and matches the hot water temperature set by the hot water temperature setting means 16. The circulation flow rate controller 17 controls the number of revolutions of the circulation pump 6 and stores it in the upper part of the hot water tank 7. Hot water is stored from the upper part of the hot water tank 7 while repeating this operation. Usually, when the amount of remaining hot water in the hot water storage tank 7 falls below a certain amount, the boiling operation is performed.
[0014]
2 shows the compressor rotation speed on the horizontal axis and the heat pump efficiency (COP) and heating capacity on the vertical axis. The relationship between the efficiency and the heating capacity with respect to the rotation speed at a certain outside temperature is the boiling temperature. It is shown as a parameter. As can be seen from FIG. 2, the efficiency has the highest value at a certain number of rotations when the boiling temperature is constant, and the number of rotations at which the maximum efficiency increases as the boiling temperature increases. On the other hand, the heating capacity is almost proportional to the number of revolutions, and decreases as the boiling temperature increases, but the difference is not large. The heating capability in FIG. 2 is expressed as a general characteristic when the refrigerant state of the radiator 2 is used in a supercritical state or lower, but when the refrigerant state of the radiator 2 is used in a supercritical state or higher, The difference due to boiling temperature tends to be almost eliminated.
[0015]
FIG. 3 is a graph showing the boiling temperature on the horizontal axis and the rotational speed at which the maximum efficiency is obtained for each boiling temperature in FIG. 2, the heating capacity at that time, and the required heating capacity on the vertical axis. The required heating capacity is, for example, the heating capacity required to boil the amount of heat necessary for boiling all the water in a predetermined hot water storage tank from the initial water temperature to the boiling temperature within a predetermined time. For example, 300 L of water Is the heating capacity required to boil the amount of heat required to boil from 20 ° C. to 60 ° C. to 90 ° C. in 8 hours. As can be seen from FIG. 3, the higher the boiling temperature, the higher the number of revolutions that achieves the highest efficiency, and the greater the heating capacity. Similarly, the required heating capacity is also increased. In other words, by utilizing the above characteristics and setting the number of rotations at which the highest efficiency can be obtained with respect to the set boiling temperature in advance, there is also an effect that the operation can be performed in accordance with the required heating capacity.
[0016]
As described above, in the present embodiment, the compressor 1, the radiator 2, the decompression device 3, and the evaporator 4 are sequentially connected to form the heat pump 5, the hot water tank 7, and the hot water tank 7 that constitute the refrigerant circuit. A circulation means 6 provided in a water circulation path communicating with the lower part and the upper part, a water circulation circuit in which a water heat exchanger 14 for heat exchange with the radiator 2 is connected in sequence, and a temperature detection provided at the outlet of the water heat exchanger 14 By providing a vessel 15, a hot water temperature setting means 16 for setting the boiling water temperature, and a rotation speed setting means 18 for setting the rotation speed of the compressor 1 based on a signal from the hot water temperature setting means 16. Since the rotational speed at which the maximum efficiency can be obtained is obtained and set with respect to the raised set temperature, the operation is always performed at the maximum efficiency, which saves energy. Furthermore, there is an effect that the operation corresponding to the required heating capacity can be performed.
[0017]
Further, by providing the compressor rotation speed setting means 18 that increases the rotation speed of the compressor 1 as the boiling setting temperature increases, the rotation speed at which the highest efficiency can be obtained as the boiling temperature increases increases. Therefore, it is always possible to operate at the highest efficiency and save energy.
[0018]
(Example 2)
FIG. 4 is an explanatory diagram showing the configuration of the heat pump water heater in the second embodiment of the present invention, and FIG. 5 is an explanatory diagram showing the rotational speed, heating capability, and required heating capability with respect to the outside air temperature of the heat pump water heater. In FIG. 4, the difference from the first embodiment is that an outside air temperature detection means 20 is provided. In addition, about the same structure and operation | movement as a 1st Example, the same code | symbol is used, and description is abbreviate | omitted.
[0019]
About the heat pump water heater comprised as mentioned above, the operation | movement and an effect | action are demonstrated below. FIG. 5 is a graph showing the outside air temperature on the horizontal axis and the rotational speed at which the maximum efficiency is obtained at a certain boiling temperature, the heating capacity at that time, and the required heating capacity on the vertical axis. As can be seen from FIG. 5, when the boiling temperature is constant, the higher the outside air temperature, the lower the maximum rotational speed and the lower the heating capacity. Similarly, the required heating capacity is also reduced. However, although the degree of decrease in the heating capacity is less than the decrease in the required heating capacity, if the heating capacity is set at a low outside air temperature, there is a margin in the heating capacity at a high outside air temperature, so the necessary heating amount is obtained. Therefore, no problem arises. That is, using the above characteristics, there is an effect that an operation corresponding to the required heating capacity can be performed by setting the rotation speed at which the highest efficiency can be obtained with respect to the outside air temperature and the boiling set temperature in advance. .
[0020]
As described above, in this embodiment, the rotation speed setting means 18 for setting the rotation speed of the compressor 1 based on the signal of the outside air temperature detection means 20 and the signal of the hot water temperature setting means 16 is provided. Since the rotation speed at which the maximum efficiency is obtained is obtained and set with respect to the outside air temperature and the boiling temperature, it is always possible to operate at the maximum efficiency and save energy. Furthermore, since it can be operated at a capacity higher than the required heating capacity, there is also an effect that there is no fear of a shortage of hot water.
[0021]
Further, by reducing the rotation speed of the compressor as the outside air temperature increases, as shown in FIG. 5, the compressor rotation speed coincides with the characteristic that the rotation speed of the compressor decreases as the outside air temperature increases. It is possible to save energy.
[0022]
【The invention's effect】
As described above, the rotational speed at which the highest efficiency can be obtained is obtained and set with respect to the outside air temperature and the boiling set temperature, so that it is always possible to operate at the highest efficiency and save energy.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing the configuration of a heat pump water heater in Embodiment 1 of the present invention. FIG. 2 is an explanatory diagram showing efficiency and heating capacity with respect to the rotation speed of a compressor of the heat pump water heater. Explanatory diagram showing the number of rotations, heating capacity and required heating capacity with respect to the boiling temperature FIG. 4 is a diagram illustrating the configuration of the heat pump water heater in the second embodiment of the present invention. Explanatory diagram showing number, heating capacity and required heating capacity [Fig. 6] Configuration diagram of conventional heat pump water heater [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Compressor 2 Radiator 3 Pressure reducing device 4 Evaporator 5 Heat pump 6 Circulation pump (circulation means)
7 Hot water storage tank 14 Water heat exchanger 15 Temperature detector 16 Hot water temperature setting means 18 Rotation speed setting means 20 Outside air temperature detection means

Claims (1)

A compressor, a radiator, a decompression device, a heat pump that connects the evaporator to form a refrigerant circuit, a hot water storage tank, circulation means provided in a water circulation path that communicates the lower and upper parts of the hot water storage tank, the radiator and heat A water circulation circuit connected to the water heat exchanger for exchanging, a hot water temperature setting means for setting the boiling water temperature to be stored in the hot water storage tank, and an outside air temperature detection means, on the outlet side of the water exchanger The compressor is operated at a rotation speed set in advance for the setting signal transmitted by the hot water temperature setting means and the signal from the outside air temperature detection means regardless of the medium temperature detected by the provided temperature detector. heat pump water heater hot water is stored in the hot water storage tank to control said circulation means so that the hot water temperature set by said hot water temperature setting means.

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