JP2021134970A - Heat pump type water heater - Google Patents

Abstract

To provide a heat pump type water heater that can properly suppress an electric power consumption of a heat pump unit by means having simple constitution, and suitably allow the heat pump unit and a hot water storage tank unit to use a common electric power supply.SOLUTION: A heat pump type water heater A comprises control means 4, 14 which control a hot water storage operation to reserve hot water, heated using a heat pump unit U1, in a hot water storage tank 2, and the control means 4, 14 include stored hot water temperature upper-limit value setting means 14a which can set, as information related to a stored hot water temperature, an upper-limit value Tu of the stored hot water temperature set to be lower when an outside air temperature is low than when high so that in the hot water storage operation, an electric power consumption of the heat pump unit U1 does not exceed a predetermined value, the stored hot water temperature being controlled to below the upper-limit value Tu in the hot water storage operation.SELECTED DRAWING: Figure 1

Description

The present invention relates to a heat pump type hot water supply device.

The applicant has previously proposed the one described in Patent Document 1 as a specific example of the heat pump type hot water supply device.
The hot water supply device described in the same document is a combination of a heat pump unit and a hot water storage tank unit having a hot water storage tank for storing hot water heated by the heat pump, and the power consumption of the entire hot water supply device is limited. By adding the above, the power supply of both units is shared. With such a configuration, it is not necessary to connect the heat pump unit and the hot water storage tank unit to different power sources. Specifically, it is not necessary to connect the hot water storage tank unit to the outdoor outlet and the heat pump unit to the indoor dedicated distribution board, and both of these units can be connected to the outdoor outlet. Therefore, it is possible to facilitate the construction work of the hot water supply device and reduce the construction cost.

However, in the above-mentioned prior art, there is still room for improvement as described below.

That is, the heat pump unit has a characteristic that the lower the outside air temperature, the lower the efficiency and the larger the load, and the power consumption of the heat pump during the hot water storage operation depends on the outside air temperature even if the hot water storage temperature is the same. The power consumption fluctuates greatly. Therefore, in order to limit the power consumption of the entire hot water supply device, it is desirable to impose a certain limit on the power consumption of the heat pump unit itself.
Here, in the above-mentioned prior art, as a specific means for limiting the power consumption of the entire hot water supply device, for example, the current flowing through the power supply circuit of the heat pump unit is measured so that the current does not exceed a predetermined value. Means for controlling the operation of the heat pump unit are adopted.
However, according to such a configuration, since an apparatus for measuring the current is indispensable, the configuration of the apparatus becomes complicated and the manufacturing cost becomes high. Further, the control of the heat pump unit based on the measured current is complicated and not easy.

Japanese Unexamined Patent Publication No. 2016-99072

The present invention has been conceived under the above-mentioned circumstances, and the power consumption of the heat pump unit can be appropriately suppressed by means having a simple configuration, and the power supply between the heat pump unit and the hot water storage tank unit can be appropriately suppressed. The challenge is to provide a heat pump type hot water supply device that is suitable for sharing the power supply.

In order to solve the above problems, the following technical measures are taken in the present invention.

The heat pump type hot water supply device provided by the present invention includes a heat pump unit, a hot water storage tank unit having a hot water storage tank, and a hot water storage tank unit capable of supplying hot water to a hot water supply destination or a heat load from the hot water storage tank, and the heat pump unit. A heat pump type hot water supply device including a control means for controlling a hot water storage operation for storing hot water heated by using the above in the hot water storage tank. Hot water storage temperature upper limit setting means capable of setting the upper limit value Tu of the hot water storage temperature, which is lower when the outside air temperature is lower than when the outside air temperature is high, so that the power consumption of the heat pump unit does not exceed a predetermined value during operation. It is characterized in that, during the hot water storage operation, the control for setting the hot water storage temperature to the upper limit value Tu or less is executed.

According to such a configuration, during the hot water storage operation, the power consumption of the heat pump unit can be prevented from exceeding the predetermined value by executing the control to set the hot water storage temperature to the above-mentioned predetermined upper limit value Tu or less. can. As a result, it is possible to suppress the power consumption of the entire heat pump type hot water supply device, and it is possible to appropriately share the power sources of the heat pump unit and the hot water storage tank unit. It is not necessary to connect one of the two units to an outdoor outlet and the other to an indoor dedicated distribution board, which makes it possible to facilitate construction work and reduce costs.
In addition, according to the present invention, unlike the prior art, it is not necessary to measure the current in the power supply circuit of the heat pump unit. On the other hand, the outside air temperature may be detected by using, for example, a temperature sensor originally used in the heat pump unit, and it is not necessary to use special and expensive equipment. Therefore, the device can be simplified and the manufacturing cost of the entire device can be reduced. Further, the control of setting the hot water storage temperature to the above-mentioned predetermined upper limit value Tu or less is relatively simple, and the control program for that purpose can be made relatively simple.

In the present invention, preferably, the control means sets a lower limit of the hot water storage temperature Tl, which enables hot water to be supplied from the hot water storage tank at a temperature equal to or higher than the target hot water supply temperature, as information on the hot water storage temperature. When the means is included and the upper limit value Tu is equal to or higher than the lower limit value Tl prior to the start of the hot water storage operation, the heat pump unit is operated to start the hot water storage operation, while the hot water storage operation is not started. Is configured not to start the hot water storage operation.

According to such a configuration, it is possible to prevent and appropriately prevent the operation of the heat pump unit from being unreasonably started so that the hot water storage temperature exceeds the upper limit value Tu. Therefore, it is more ensured that the power consumption of the heat pump unit does not exceed a predetermined value.

In the present invention, preferably, the control means is configured to stop the hot water storage operation when the relationship in which the upper limit value Tu is equal to or higher than the lower limit value Tl is not established during the hot water storage operation. ..

According to such a configuration, after the start of operation of the heat pump unit, for example, the hot water storage temperature may exceed the upper limit value Tu due to a decrease in the outside air temperature or a change in the setting of the target hot water supply temperature. It can be prevented from occurring. Therefore, it is possible to further ensure that the power consumption of the heat pump unit does not exceed a predetermined value.

In the present invention, preferably, when the hot water storage operation is started, if the hot water storage operation is an automatic operation based on the judgment of the control means itself, the control means is set as the initial value Tir of the hot water storage temperature. While the lower limit value Tl is set, when the hot water storage operation is a manual operation based on a user's operation, a predetermined maximum hot water storage temperature Tmax is set as the initial value Tir.

According to such a configuration, when the heat pump unit is automatically operated, the hot water storage temperature is lowered, so that the heat pump unit can be operated in an efficient state. On the other hand, when the heat pump unit is manually operated, the hot water storage temperature is set to a high temperature (predetermined maximum hot water storage temperature Tmax), so that the amount of heat stored in the hot water storage tank is increased as much as possible in response to the needs of the user. It becomes possible.

In the present invention, preferably, the control means maintains the initial value Tir as it is when the initial value Tir of the hot water storage temperature is equal to or less than the upper limit value Tu, while the control means otherwise maintains the initial value Tir. It is configured to change the value Tir to the upper limit value Tu.

According to such a configuration, as long as the hot water storage temperature does not exceed the upper limit value Tu, hot water storage operation with the hot water storage temperature as a preferable temperature is possible, but when such a situation becomes difficult, hot water storage is possible. It is possible to appropriately continue the hot water storage operation in a situation where the hot water storage temperature does not exceed the upper limit value Tu even though the temperature is changed.

In the present invention, preferably, the first operating state in which the control means executes control to set the hot water storage temperature to the upper limit value Tu or less, and the first operating state are released, and the hot water storage temperature is set to the upper limit value. Further, it is provided with a switching means capable of selectively switching and setting either one of the second operating state in which the control of Tu or less is not executed.

According to such a configuration, when the heat pump unit and the hot water storage tank unit are connected to the same power source, the first operating state is set, and the heat pump unit is connected to an indoor dedicated distribution board suitable for the first operating state. In this case, the second operating state can be set, and the heat pump unit can be operated in a state where the hot water storage temperature is not limited to the upper limit value Tu. Regardless of the above-mentioned two types of connection modes of the heat pump unit and the hot water storage tank unit to the power source, it is possible to suitably cope with them.

Other features and advantages of the present invention will become more apparent from the following description of embodiments of the invention with reference to the accompanying drawings.

It is a schematic explanatory drawing which shows an example of the heat pump type hot water supply apparatus which concerns on this invention. It is a flowchart which shows an example of the operation processing procedure at the time of starting the heat pump of the heat pump type hot water supply apparatus shown in FIG. FIG. 5 is a flowchart showing an example of an operation processing procedure when the heat pump of the heat pump type hot water supply device shown in FIG. 1 is stopped from the operating state. It is a flowchart which shows another example of the operation processing procedure executed by the heat pump type hot water supply apparatus shown in FIG.

Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings.

The heat pump type hot water supply device A shown in FIG. 1 is configured by combining a heat pump unit U1 and a hot water storage tank unit U2.

The heat pump unit U1 includes a heat pump 1, a control unit 14, and a power supply circuit 15 for supplying necessary electric power to each unit of the heat pump 1. The heat pump 1 is the same as that conventionally known, for example, an evaporator 10, a compressor 11, and a hot water heater for absorbing heat from air taken in by using a fan 10a in a circulation path of a refrigerant such as _{CO 2.} A condensate heat exchanger 12 (condenser) and an expansion valve 13 are provided. The control unit 14 will be described later.
The heat pump unit U1 is provided with a temperature sensor Sc for detecting the outside air temperature and a temperature sensor Sb for detecting the outlet temperature (hot water heating temperature) of the condensing heat exchanger 12.

The hot water storage tank unit U2 includes a hot water storage tank 2, an auxiliary heat source machine 3, a control unit 4, and a power supply circuit 25 for supplying necessary power to each part of the hot water storage tank unit U2.

The lower part and the upper part of the hot water storage tank 2 are connected (pipe connection) to the condensing heat exchanger 12 of the heat pump 1 via the hot water flow path 5a and the hot water return flow path 5b. During the hot water storage operation, the circulation pump P1 provided in the hot water flow path 5a is driven, so that the hot water flowing out from the lower part of the hot water storage tank 2 to the hot water flow path 5a is sent to the condensed heat exchanger 12. Is heated. The heated hot water is returned to the upper part in the hot water storage tank 2 via the hot water return flow path 5b. A plurality of temperature sensors Sa are mounted on the hot water storage tank 2, and the control unit 4 can determine the amount of hot water stored (heat storage amount) in the hot water storage tank 2 based on the detection signals from these temperature sensors Sa.

A water inlet pipe 61 having a water inlet 61a and a hot water outlet pipe 62 having a hot water outlet 62a are separately connected to the lower part and the upper part of the hot water storage tank 2. The hot water tap 90 connected to the hot water outlet 62a by a pipe is opened, and the hot water in the hot water storage tank 2 flows out to the hot water pipe 62, so that the hot water is supplied toward the hot water tap 90 (general hot water supply).

In the hot water storage tank unit U2, in addition to the above-mentioned general hot water supply, hot water filling and bath reheating to the bathtub 91, heating operation by supplying hot water (heat medium) to the heating terminal 92, and antifreezing operation are also possible. Further, when the amount of heat stored (the amount of hot water stored) in the hot water storage tank 2 is insufficient, it is possible to make up for the insufficient amount of heat by using the auxiliary heat source machine 3.
Specifically, the hot water storage tank unit U2 includes a flow path 63 capable of filling the bathtub 91 with hot water, a circulation pump P2 and a heat exchanger 8a capable of reheating the bath, and a circulation pump for the heating terminal 92. A heat medium circulation flow path 64 having P3 and a heat exchanger 8b, and various hot water flow paths, valves, pumps, and the like related thereto are provided.

The auxiliary heat source machine 3 is similar to, for example, a gas instantaneous water heater, in which the burner 30 and the heat exchanger 31 are housed in the can body 32, and the hot water supplied to the heat exchanger 31 via the pump P4 is burned. It is configured so that it can be heated quickly by 30. The auxiliary heat source machine 3 heats the hot water that has entered the water inlet 61a and has flowed into the auxiliary heat source machine 3 without passing through the hot water storage tank 2, and the heated hot water is discharged from the hot water outlet 62a. It is also possible to perform the general hot water supply operation and the hot water storage operation in which the hot water discharged from the hot water storage tank 2 is heated and stored in the hot water storage tank 2.

The control units 4 and 14 are configured by using a microcomputer or the like, and the control unit 4 executes operation control and data processing of each part of the hot water storage tank unit U2, whereas the control unit 14 is a heat pump unit U1. Executes operation control and data processing of each part of.
These control units 4 and 14 correspond to an example of the control means referred to in the present invention, and they cooperate to execute overall operation control of the heat pump type hot water supply device A and control the hot water storage operation described later.

From a functional point of view, the control units 4 and 14 set the hot water storage temperature upper limit value setting unit 14a and the hot water storage temperature lower limit value as means for setting information necessary for controlling the hot water storage operation in both or one of them. It includes a setting unit 14b and a hot water storage temperature initial value setting unit 4a. In FIG. 1, the former two are provided in the control unit 14, and the latter is provided in the control unit 4, but the latter is not limited to this, and they are provided in any of the control units 4 and 14. good. The hot water storage temperature is the hot water temperature stored in the hot water storage tank 2 via the heat pump 1, in other words, the hot water heating temperature by the heat pump 1, and can be detected by using the temperature sensor Sb.

A remote controller 40 is communicated with the control unit 4. The remote controller 40 has a display unit 41 for data, a plurality of operation switches 42, and the like, and by operating the operation switches 42, for example, as will be described later, a first operating state and a second operating state can be obtained. Can be switched and set. The control units 4 and 14 have a learning ability to predict future heat demand based on the past heat demand (hot water supply operation record), and can start the hot water storage operation (automatic operation) at an appropriate timing. However, in addition to this, it is also possible for the user to start the hot water storage operation (manual operation) by operating the remote controller 40.

In the heat pump type hot water supply device A of the present embodiment, operation control is possible so that the total maximum power consumption of the heat pump unit U1 and the hot water storage tank unit U2 does not exceed a predetermined value. Specifically, the operation can be controlled so that the total current flowing through the power supply circuits 15 and 25 does not exceed, for example, 15 A. Therefore, the heat pump type hot water supply device A can be appropriately operated with the two power supply circuits 15 and 25 connected to the common commercial power outlet 99 by wiring.

Next, the operation processing procedure executed in the heat pump type hot water supply device A will be described with reference to the flowcharts shown in FIGS. 2 and 3. At the same time, the action at that time will be described.

First, when the hot water storage operation is started from the state where the operation of the heat pump 1 is stopped, the upper limit value Tu, the lower limit value Tl, and the initial value Tir of the hot water storage temperature are determined (S1: YES, S2 to S4). ).
Here, the upper limit value Tu is a value of the upper limit of the hot water storage temperature for preventing the power consumption of the heat pump unit U1 from exceeding a predetermined value, and is lower when the outside air temperature is lower than when it is high. When the hot water storage temperature exceeds this upper limit value Tu, the power consumption of the heat pump unit U1 exceeds the predetermined value.
The lower limit value Tl is a lower limit value of the hot water storage temperature that enables hot water supply at a temperature equal to or higher than the target hot water supply temperature from the hot water storage tank 2. This lower limit value Tl is set to a temperature higher than the target hot water supply temperature in consideration of heat dissipation from the hot water storage tank 2.

The initial value Tir is the initial hot water storage temperature which is a temporary target temperature when the hot water storage operation is started. This initial value Tir is set to the above-mentioned lower limit value Tl when the hot water storage operation is an automatic operation based on learning of the control units 4 and 14. In the case of automatic operation, efficient hot water storage operation is required, but if the initial value Tir is set to the lower limit value Tl, hot water storage operation that meets such a request becomes possible.
On the other hand, when the hot water storage operation is a manual operation based on the operation of the user, the above-mentioned initial value Tir is set to a predetermined maximum hot water storage temperature Tmax. This maximum hot water storage temperature Tmax is the same as the hottest hot water heating temperature set in the heat pump unit U1. Since the manual operation is generally performed by the user in an attempt to increase the amount of heat stored in the hot water storage tank 2, if the initial value Tir is set to the maximum hot water storage temperature Tmax in the case of the manual operation, the above-mentioned user's request is met. It will be responsive.

After the upper limit value Tu, the lower limit value Tl, and the initial value Tir are determined, the upper limit value Tu and the lower limit value Tl are compared (S5). In this comparison, if the lower limit value Tl is higher than the upper limit value Tu and the relationship of upper limit value Tu ≥ lower limit value Tl is not established, the hot water storage operation is not started (S5: NO). In such a case, if the hot water storage operation is started and the hot water storage temperature is set to the lower limit value Tu, the hot water storage temperature exceeds the upper limit value Tu, which is not appropriate.
When the hot water storage operation is not performed because the relationship of the upper limit value Tu ≧ lower limit value Tl is not established, for example, when the user performs a switch operation for starting the hot water storage operation, this switch operation is invalidated. At the same time, a notification operation such as displaying the fact on the display unit 41 of the remote controller 40 is performed.

On the other hand, when the relationship of the upper limit value Tu ≥ the lower limit value Tl is established, the hot water storage operation is started, but prior to that, the upper limit value Tu and the initial value Tir are compared (S5: YES, S6). .. In this comparison, when the relationship of the upper limit value Tu ≧ initial value Tir is established, the initial value Tir is left as it is, and the operation of the heat pump unit U1 is started so that the hot water is heated at the temperature of this initial value Tir. , Hot water storage operation is also started (S6: YES, S7, S8). As described above, the initial value Tir is set to the hot water storage temperature suitable for the operation depending on whether the hot water storage operation is automatic operation or manual operation, but according to the above-mentioned control, the hot water storage temperature is the upper limit value. It is possible to optimize or approach the hot water storage temperature while not exceeding Tu.
On the other hand, when the relationship of the upper limit value Tu ≧ initial value Tir is not established, the initial value Tir is changed to the upper limit value Tu, and then the heat pump unit U1 is operated so that hot water is heated at the temperature of this upper limit value Tu. Is started (S6: NO, S9, S8). As a result, the hot water storage operation can be appropriately executed so that the hot water storage temperature does not exceed the upper limit value Tu.

After the hot water storage operation is started as described above, when the amount of heat stored in the hot water storage tank 2 reaches the desired amount of heat storage, the operation of the heat pump unit U1 is stopped and the hot water storage operation ends ( S11: NO, S17), otherwise, the following control is executed.

That is, during the hot water storage operation, the upper limit value Tu and the lower limit value Tl of the hot water storage temperature are determined in response to changes in the outside air temperature and changes in the hot water supply target temperature at all times or almost all the time (S11: NO, S12, S13). Next, when these values are compared and the relationship of the upper limit value Tu ≧ lower limit value Tl is not established, the hot water storage operation is stopped (S14: NO, S17). When the relationship of upper limit value Tu ≥ lower limit value Tl is established, the hot water storage operation is continuously executed, but when the relationship of upper limit value Tu ≥ initial value Tir is established, the initial value Tir is maintained as it is. If not, the initial value Tir is changed to the upper limit value Tu. Such control is the same as the control performed at the start of operation of the heat pump unit U1, and it is possible to make the hot water storage temperature optimal or close to the optimum temperature while preventing the hot water storage temperature from exceeding the upper limit value Tu. Is.

In the heat pump type hot water supply device A, the operation control as shown in FIG. 4 can be further executed.
That is, when the heat pump unit U1 is operated to start the hot water storage operation, the remote controller 40 determines which of the first and second operating states is selectively set by the control units 4 and 14. (S21: YES, S22). As a result of this determination, when the first operating state is set, the hot water storage operation of the operation control (control to set the hot water storage temperature to the upper limit value Tu or less) shown in FIGS. 2 and 3 is performed (S22: YES, S23). On the other hand, when the second operating state is set, the hot water storage of the normal control (control that does not suppress the hot water storage temperature to the upper limit value Tu or less) different from the operation control shown in FIGS. 2 and 3 is set. The operation is performed (S22: NO, S24).

According to such a configuration, as shown in FIG. 1, when the heat pump unit U1 and the hot water storage tank unit U2 are connected to the same commercial power outlet 99, the first operating state is set. , The total power consumption of the heat pump type hot water supply device A can be suppressed to a predetermined value or less. On the other hand, unlike the above, when the heat pump unit U1 is separately connected to the indoor dedicated distribution board (not shown), the hot water storage temperature is set to the upper limit value by setting the second operating state. It is possible to operate the heat pump unit U1 at full capacity without being limited to Tu.
The remote controller 40 corresponds to an example of switching means capable of switching and setting the first and second operating states, and as the switching means, means other than the remote controller 40 can be used.

The present invention is not limited to the contents of the above-described embodiments. The specific configuration of each part of the heat pump type hot water supply device according to the present invention can be variously redesigned within the range intended by the present invention.
The upper limit value Tu, the lower limit value Tl, the initial value Tir, and the like of the hot water storage temperature in the present invention can be appropriately changed according to the specifications and specification conditions of the heat pump type hot water supply device, and these specific values are not limited.
The specific type of heat pump (type of refrigerant, etc.) is also not limited.

A Heat pump type hot water supply device U1 Heat pump unit U2 Hot water storage tank unit 1 Heat pump 2 Hot water storage tank 4, 14 Control unit (control means)
40 Remote control (switching means)

Claims (6)

With the heat pump unit
A hot water storage tank unit that has a hot water storage tank and is capable of supplying hot water to the hot water supply destination or heat load from this hot water storage tank.
A control means for controlling a hot water storage operation in which hot water heated by using the heat pump unit is stored in the hot water storage tank, and
It is a heat pump type hot water supply device equipped with
As information on the hot water storage temperature, the control means determines that the hot water storage temperature is lower when the outside air temperature is lower than when the outside air temperature is high so that the power consumption of the heat pump unit does not exceed a predetermined value during the hot water storage operation. It is characterized in that it includes a hot water storage temperature upper limit value setting means capable of setting an upper limit value Tu, and is configured to execute control to set the hot water storage temperature to the upper limit value Tu or less during the hot water storage operation. Heat pump type hot water supply device. The heat pump type hot water supply device according to claim 1.
The control means includes, as information on the hot water storage temperature, a hot water storage temperature lower limit setting means capable of setting a lower limit value Tl of the hot water storage temperature that enables hot water supply at a temperature equal to or higher than the target hot water supply temperature from the hot water storage tank. Prior to the start of the hot water storage operation, if the upper limit value Tu is equal to or higher than the lower limit value Tl, the heat pump unit is operated to start the hot water storage operation, but if not, the hot water storage operation is not started. A heat pump type hot water supply device that is configured as such. The heat pump type hot water supply device according to claim 2.
The control means is a heat pump type hot water supply device configured to stop the hot water storage operation when the relationship in which the upper limit value Tu is equal to or higher than the lower limit value Tl is not established during the hot water storage operation. The heat pump type hot water supply device according to any one of claims 1 to 3.
When the hot water storage operation is started, the control means sets the lower limit value Tl as the initial value Tir of the hot water storage temperature when the hot water storage operation is an automatic operation based on the judgment of the control means itself. A heat pump type hot water supply device configured to set a predetermined maximum hot water storage temperature Tmax as the initial value Tir when the hot water storage operation is a manual operation based on a user's operation. The heat pump type hot water supply device according to claim 4.
When the initial value Tir of the hot water storage temperature is equal to or less than the upper limit value Tu, the control means maintains the initial value Tir as it is, and when not, the control means sets the initial value Tir to the upper limit value Tu. A heat pump water heater that is configured to change to. The heat pump type hot water supply device according to any one of claims 1 to 5.
The control means executes a first operating state for executing control to set the hot water storage temperature to the upper limit value Tu or less, and a control for releasing the first operating state to set the hot water storage temperature to the upper limit value Tu or less. A heat pump type hot water supply device further comprising a switching means capable of selectively switching and setting either of the second operating state and the non-second operating state.

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