WO2014174678A1

WO2014174678A1 - Heat pump hot-water supply device and hot-water storage system equipped with heat pump hot-water supply device

Info

Publication number: WO2014174678A1
Application number: PCT/JP2013/062452
Authority: WO
Inventors: 亮宜倉地; 大林　誠善
Original assignee: 三菱電機株式会社
Priority date: 2013-04-26
Filing date: 2013-04-26
Publication date: 2014-10-30
Also published as: EP2990736B1; EP2990736A4; JPWO2014174678A1; EP2990736A1; JP5972456B2

Abstract

A heat pump hot-water supply device is equipped with: a heat pump cycle device (50), wherein at least a compressor (51), a refrigerant-water heat exchanger (52), a decompression device (53), and an evaporator (54) are connected by piping, with heat being exchanged between the refrigerant and the water in the refrigerant-water heat exchanger (52); a flow volume detection means (40) that detects the flow volume of the water flowing through the refrigerant-water heat exchanger (52); and a control means (60) that controls the operation of the heat pump cycle device (50). When a state in which the flow volume of the water as detected by the flow volume detection means (40) is less than a threshold value continues for an amount of time equal to or greater than a set time (T1), the control means (60) determines that a water outage error has occurred, and stops the operation of the heat pump cycle device (50).

Description

Heat pump water heater and hot water storage system equipped with heat pump water heater

The present invention relates to a heat pump water heater and a hot water storage system including the heat pump water heater.

In recent years, development of a heat pump device using a natural refrigerant has been actively promoted in response to the flow of defluorination. Among them, the spread of heat pump devices using carbon dioxide (CO ₂ ) as a refrigerant is increasing year by year. Since CO ₂ has the characteristics that the ozone depletion coefficient is 0 and the global warming coefficient is 1, there is an advantage that the burden on the environment can be reduced. In addition, CO ₂ is excellent in safety in that it has no toxicity and is not flammable, and has the advantages of being easily available and relatively inexpensive.

Further, the high-pressure side CO ₂ discharged from the compressor has a characteristic of being in a supercritical state, unlike a fluorocarbon refrigerant. That is, the CO ₂ in the supercritical state does not condense and remains in the supercritical state when heat is applied to another fluid (for example, water, air, refrigerant, etc.) by heat exchange. CO ₂ having such characteristics has little loss due to state transition, and is suitable for heat pump devices that require high temperatures. Therefore, various heat pump water heaters have been proposed that use CO ₂ as a refrigerant and take advantage of CO ₂ to boil water to a high temperature of 90 [° C.] or higher.

As such, “a hot water supply heating means, a hot water storage tank for storing hot water heated by the hot water supply heating means, a plurality of heat radiation means for circulating the hot water stored in the hot water storage tank as a heat source, Selection means for selecting whether or not to use the heat dissipating means, and control means for controlling the hot water heating operation for heating the hot water heating means and storing the hot water in the hot water storage tank according to the selection status of the selection means. A hot water heater has been disclosed (see, for example, Patent Document 1). In this heat pump water heater, the flow rate of hot water is controlled by a circulation pump.

In general, in a heat pump water heater, as described in Patent Document 1, the hot water heated by the hot water heater is supplied to the hot water tank, or the hot water stored in the hot water tank is circulated to the heat pump water heater. A pump is used to warm. This pump is provided in the water heater or connected to the water heater.

Also, in such a water heater, it is necessary to prepare for the case where the water supplied to the heat pump water heater is cut off or the water pressure is lowered. For this reason, conventionally, in order to protect the compressor and the like at the time of water shutoff, a water cooling type cooling device provided with a water shutoff detecting means for detecting the discharge side pressure of the compressor and controlling the operation of the compressor based on the output of the water shutoff detecting means. Has been proposed (see, for example, Patent Document 2).

Japanese Unexamined Patent Publication No. 2004-333051 (page 4, FIG. 1) JP-A-7-229653 (page 3, FIG. 1)

However, when the configuration relating to the water break detection means described in Patent Document 2 and the control operation of the compressor based on this is applied to a heat pump water heater that controls the flow rate of hot water using the pump described in Patent Document 1, the pump is turned off when water is shut down. There is a risk of failure. Examples of cases where the pump fails in the above-described configuration include, for example, a case where the pump fails due to a lack of water detection in an operation where the pressure does not increase (such as a pump operation mode), or a time until the pressure increases due to frequency reduction suppression control. There is a case where the pump breaks down before it is detected. If the pump fails, even if the heat pump operation is restarted after the water is shut off, the hot water heated by the hot water heating means cannot be sent to the hot water tank and cannot be stored, or the hot water stored in the hot water tank cannot be stored. The problem arises that it cannot be circulated through the machine.

Moreover, although the pressure switch is described in patent document 2 as a water stop detection method, in the water stop detection method like a pressure switch, water stop may be misdetected or a pump may be broken. . Specific examples will be described below with reference to the drawings. FIG. 8 is a diagram for explaining a problem of the prior art. 8A and 8B show a hot water storage system in which the hot water tank 1 and the hot water heater 130 are connected by a water inflow pipe 131 having a valve body 134 and a water outflow pipe 132 having a valve body 135. An example is shown. As shown to Fig.8 (a), when the hot water storage tank 101 and the water heater 130 are connected by the water outflow piping 132 of the torii shape (shape shown by the code | symbol 180 bent upward), When the hot water storage tank 101 and the water heater 130 are connected by a water inflow pipe 131 having a reverse torii shape (a shape indicated by a reference numeral 181 bent downward) as shown in FIG. There is a possibility that the air will not escape and the pump will bite into the air and will not be able to suck in water or hot water, causing a temporary decrease in flow rate. If it becomes so, even if it is the temporary flow rate fall which returns after several seconds, the water cutoff detection means which consists of a pressure switch of patent document 2 may detect this accidentally as water cutoff. In the present invention, even if the flow rate of water decreases, a temporary decrease in the flow rate that returns after a few seconds is not treated as a water outage.

8 (c) and 8 (d) are diagrams showing an example of a connection pipe (including a water outflow pipe and a water inflow pipe) to the water heater 130 and a valve provided in the connection pipe. When the three-way valve 182 is connected to the connection pipe of the water heater 130 as shown in FIG. 8C, or two or more two-way valves are connected to the connection pipe of the water heater 130 as shown in FIG. When the (two-

way valves

183a and 183b) are connected, a temporary flow rate drop occurs during valve operation such as channel switching. FIG. 9 is a graph showing an example of the relationship between the valve opening and the flow rate when the flow path is switched using the two-

way valves

183a and 183b shown in FIG. As shown in FIG. 9, when the two-

way valves

183a and 183b are operated in order to switch the flow path, a temporary flow rate drop occurs. Although not shown, the three-way valve 182 also has a temporary flow rate drop as in FIG. In this case, there is a possibility that the water breakage detection means including the pressure switch described in Patent Document 2 will detect this temporary flow rate drop as waterfall by mistake.

Furthermore, even if the operation of the compressor or the like is stopped to protect the equipment when a temporary flow rate drop occurs as described above, there is no reproducibility when pursuing the cause of the abnormal stop. There arises a problem that it is difficult to clarify.

The present invention has been made against the background of the above problems, and even when a temporary flow rate drop occurs, a heat pump water heater that can be operated without hindrance thereafter, and a hot water storage provided with the heat pump water heater A system is provided.

The heat pump water heater according to the present invention includes a compressor, a refrigerant-water heat exchanger, a decompression device, and an evaporator at least connected to a pipe, and the refrigerant-water heat exchanger performs heat exchange between the refrigerant and water. And a flow rate detection means for detecting the flow rate of water flowing through the refrigerant-water heat exchanger, and a control means for controlling the operation of the heat pump cycle device, wherein the flow rate of water detected by the flow rate detection means is When the state lower than the threshold value continues for a set time or longer, the control means determines that the water supply is abnormal and stops the operation of the heat pump cycle device.

According to the present invention, when the state in which the flow rate of water flowing through the refrigerant-water heat exchanger is lower than the threshold value continues for a set time or longer, it is determined that the water supply is abnormal and the operation of the heat pump cycle device is stopped. For this reason, it is possible to suppress erroneous detection of the water-stopping state due to, for example, malfunction of the flow rate detection means due to noise or the like, or temporary decrease in flow rate. In addition, even if a temporary flow rate drop occurs, the pump can be operated without any trouble after the temporary flow rate drop as long as the pump that circulates water through the refrigerant-water heat exchanger does not fail. can get.

It is a piping circuit diagram which shows the hot water storage system 100 which concerns on Embodiment 1 of this invention. It is a piping circuit diagram which shows the water heater 30 which concerns on Embodiment 1 of this invention. It is a flowchart which shows the determination process of the water break detection of the water heater 30 which concerns on Embodiment 1 of this invention. It is a graph which shows an example of the relationship between the flow volume of the water which flows through the refrigerant | coolant-water heat exchanger 52 which concerns on embodiment of this invention, and elapsed time. It is a graph which shows an example of the relationship between the temperature of pump built-in components, and operation elapsed time. It is a piping circuit diagram which shows the hot water storage system 100 which concerns on Embodiment 2 of this invention. It is a flowchart explaining operation | movement of the water heater 30 which concerns on Embodiment 2 of this invention. It is a figure which shows an example of the piping connection form of the water heater 130 and the hot water storage tank 101. FIG. It is a graph which shows an example of the relationship between the valve opening degree and the flow rate when the flow path switching operation is performed when two two-way valves are connected to the hot water heater.

Hereinafter, an embodiment in which the heat pump water heater according to the present invention is applied to a hot water storage system including a hot water tank will be described with reference to the drawings. In the following drawings, the size relationship of each component may be different from the actual one. Moreover, in the following drawings, what attached | subjected the same code | symbol is the same or it corresponds, This is common in the whole text of a specification. Furthermore, the forms of the constituent elements shown in the entire specification are merely examples, and are not limited to these descriptions.

Embodiment 1 FIG.
FIG. 1 is a piping circuit diagram showing a hot water storage system 100 according to Embodiment 1 of the present invention. In addition, in FIG. 1, the flow direction of water is also shown by the broken-line arrow. A hot water storage system 100 according to the present embodiment includes a hot water storage tank 1 and a heat pump water heater 30 (hereinafter simply referred to as a hot water heater 30) that is means for heating water in the hot water tank 1. Hot water heated by the hot water heater 30 is stored in the hot water tank 1, and hot water is supplied from the hot water tank 1 to a water tap of a facility (for example, a bathroom or a kitchen) that uses the hot water.

The lower part of the hot water tank 1 is connected to the water heater 30 via a water inflow pipe 31 through which the water in the hot water tank 1 flows into the water heater 30. Below the hot water tank 1, a temperature detector 2 is provided for detecting the water temperature at substantially the same height as the part to which the water inflow pipe 31 is connected. The specific structure of the temperature detector 2 is not limited as long as it can detect the water temperature. In addition, the upper part of the hot water tank 1, specifically the upper part than the part where the water inflow pipe 31 is connected, is connected to the hot water heater 30 via a water outflow pipe 32 through which water flowing out of the hot water heater 30 flows. The water inflow pipe 31 is branched between the hot water storage tank 1 and the water heater 30, and this branched pipe is referred to as a water inflow pipe 31a. The water inflow pipe 31 a is connected to the water receiving tank 3 through the water supply pipe 4. The water receiving tank 3 is a tank that stores water to be supplied to the hot water storage system 100. The water supply pipe 4 is provided with a water supply valve 5 that controls the amount of water supplied from the water receiving tank 3 to the water heater 30.

Each of the water inflow pipe 31 and the water outflow pipe 32 is, for example, a valve that is a manual valve in order to shut off the water piping path between the water heater 30 and the hot water tank 1 during maintenance or replacement of the water heater 30. The body is provided. Specifically, the water inflow pipe 31 is provided with a valve body 33 and a valve body 34 in series, and the water inflow pipe 31 a is branched from between the valve body 33 and the valve body 34. The water outflow pipe 32 is provided with a valve body 35.

One end of a hot water supply pipe 6 connected to a water tap (not shown) is connected to the upper part of the hot water tank 1. The hot water supply pipe 6 is provided with a hot water supply pump 7 for sending hot water stored in the hot water tank 1 to the water tap. In addition, one end of the return pipe 8 is connected to the lower part of the hot water tank 1, more specifically below the part to which the hot water supply pipe 6 is connected. The hot water supply pump 7 may be provided in the return pipe 8.

Next, the configuration of the water heater 30 will be described.
FIG. 2 is a piping circuit diagram illustrating the water heater 30 according to Embodiment 1 of the present invention. In FIG. 2, the direction of water flow is indicated by a broken-line arrow, and the direction of refrigerant flow is indicated by a solid-line arrow. The water heater 30 according to the present embodiment includes a heat pump cycle device (same as the refrigeration cycle device) 50 as a heat source. In the present embodiment, the heat pump cycle device 50 uses a CO ₂ refrigerant. The high-pressure CO ₂ refrigerant has a characteristic of being in a supercritical state. That is, the CO ₂ refrigerant in the supercritical state does not condense when heat is applied to another fluid (here, water) by heat exchange, and remains in the supercritical state. For this reason, there is little loss by a state transition and it is suitable for heating water to high temperature.

In this heat pump cycle device 50, a compressor 51, a refrigerant-water heat exchanger 52 as a radiator, a decompression device 53, and an evaporator 54 are sequentially connected to form a refrigerant circuit. The compressor 51 is connected to a refrigerant-water heat exchanger 52 via a refrigerant inflow pipe 55. The refrigerant-water heat exchanger 52 is connected to the decompression device 53 via a refrigerant outflow pipe 56. Further, the decompression device 53 is connected to the evaporator 54 by piping, and the evaporator 54 is connected to the compressor 51 by piping. Note that the refrigerant used in the heat pump cycle device 50 is not limited to CO ₂ , for example, HFC (hydrofluorocarbon) refrigerants such as R410A, R407C, R404A, and R32, HCFC (hydrochlorofluorocarbon) refrigerants such as R22 and R134a, or carbonization Various refrigerants such as natural refrigerants such as hydrogen and helium can be used. In this case, the refrigerant-water heat exchanger 52 functions as a condenser.

In this heat pump cycle device 50, the high-temperature and high-pressure refrigerant discharged from the compressor 51 flows into the refrigerant-water heat exchanger 52 and flows through the refrigerant-water heat exchanger 52 (in this embodiment, water). Heat is exchanged between the refrigerant and the water to dissipate the heat and flows out of the refrigerant-water heat exchanger 52. The refrigerant that has flowed out of the refrigerant-water heat exchanger 52 is decompressed by the decompression device 53, flows into the evaporator 54, rises in temperature, and is sucked into the compressor 51. The number of refrigerant-water heat exchangers 52 is not limited, and one or a plurality of refrigerant-water heat exchangers 52 can be provided in accordance with the required heating amount of water.

A water inflow pipe 31 and a water outflow pipe 32 are connected to the refrigerant-water heat exchanger 52. The water flowing into the refrigerant-water heat exchanger 52 through the water inflow pipe 31 exchanges heat with the refrigerant flowing through the refrigerant-water heat exchanger 52, and passes through the water outflow pipe 32 to pass through the hot water tank 1 ( 1). The water inflow pipe 31 is provided with a water supply pump 36 for sending water to the refrigerant-water heat exchanger 52. The feed water pump 36 may be capable of adjusting the flow rate by making the rotation speed variable, or may be a constant flow rate (rotation speed). Further, the water supply pump 36 may be provided in the water outflow pipe 32. Moreover, the water supply pump 36 may be incorporated in the water heater 30 as shown in FIG. 2, or may be provided in a portion of the water inflow pipe 31 or the water outflow pipe 32 exposed from the outline of the water heater 30. Good.

The water inflow pipe 31 is provided with a flow rate detection means 40 for detecting the flow rate of water flowing through the refrigerant-water heat exchanger 52. The flow rate detection means 40 can be configured by an arbitrary flow rate sensor such as an electric type, a mechanical type, an ultrasonic type, or a thermal type. In the example of FIG. 2, since the flow rate detection unit 40 uses a volumetric flow rate detection device, the refrigerant may generate bubbles before passing through the water supply pump 36 where cavitation may occur. -A flow rate detection means 40 is provided between the water supply pump 36 of the water inflow pipe 31 and the refrigerant-water heat exchanger 52 as a position where the pressure becomes highest, avoiding the position after passing through the water heat exchanger 52. Yes.

Information detected by the flow rate detection means 40 and the temperature detector 2 is input into the housing of the hot water heater 30 and at least control means for controlling the operation of the hot water supply pump 7, the

valve bodies

34 and 35, and the compressor 51. 60. When the decompression device 53 is configured by an expansion valve whose valve opening degree can be adjusted, the operation of the decompression device 53 can be controlled by the control means 60, and the valve body 34 and the valve body 35 are opened. The control means 60 can also control these valves as long as they are adjustable. In the present embodiment, as shown in FIG. 2, the control means 60 is provided in the housing of the water heater 30, but the installation position of the control means 60 is arbitrary. The control means 60 may be realized by a CPU and a program that is analyzed and executed by the CPU, or may be realized as hardware by wired logic. It should be noted that the functions realized by the control means 60 can also be realized by devices physically distributed in arbitrary units. Further, the control means 60 has a rewritable storage means 61 and can record the flow rate detected by the flow rate detection means 40 in the storage means 61 as will be described later.

Further, the water heater 30 is provided with a notification means 62 for notifying the operating state of the water heater 30 and information to be notified to the user. The notification means 62 is, for example, a display device such as a liquid crystal monitor that visually displays information, or a sound output device such as a speaker or buzzer that notifies information audibly. Note that both a display device and an audio output device may be provided as the notification means 62, or either one may be provided.

Next, the operation will be described.
The hot water storage system 100 of the present embodiment heats the water stored in the hot water storage tank 1 or the water stored in the water receiving tank 3 with the hot water heater 30 (refrigerant-water heat exchanger 52), and hot water storage tank Send to 1. Then, the control means 60 of the present embodiment sets the operation mode of the water heater 30 as a circulation mode in which water is circulated and heated between the water heater 30 (refrigerant-water heat exchanger 52) and the hot water tank 1. In addition, at least two operation modes of hot water storage mode in which hot water heated by the water heater 30 is stored in the hot water storage tank 1 are provided. The hot water storage mode is different from the circulation mode in that the water supplied from the water receiving tank 3 is heated by the water heater 30 to store the hot water in the hot water tank 1 and no water is sent from the hot water tank 1 to the water heater 30. Hereinafter, with reference to FIG. 1, FIG. 2, the operation | movement outline | summary of the circulation mode and the hot water storage mode is demonstrated.

In the circulation mode, the water heated by the water heater 30 (refrigerant-water heat exchanger 52) is water stored in the hot water tank 1. The water temperature in the hot water tank 1 is higher at the upper part, and the water temperature is lower toward the lower part. In the present embodiment, the control means 60 is stored in the hot water tank 1 when the detected water temperature of the temperature detector 2 provided in the lower part of the hot water tank 1 becomes a predetermined heating start temperature or lower. The water heater 30 is operated to start heating the water. When starting the heating of the water stored in the hot water tank 1, the control means 60 opens the valve body 33, the valve body 34, and the valve body 35 and operates the water supply pump 36. The water stored in the lower part of the hot water tank 1 is sent to the hot water heater 30 (refrigerant-water heat exchanger 52) via the water inflow pipe 31. This water is heated by the hot water heater 30 (refrigerant-water heat exchanger 52) to become hot water. The warm water flows into the hot water tank 1 through the water outflow pipe 32. When the temperature detected by the temperature detector 2 reaches a predetermined heating end temperature, the heating of the water stored in the hot water tank 1 is completed. The hot water stored in the hot water tank 1 is supplied to a water tap (not shown) through the hot water supply pipe 6 when the hot water supply pump 7 is operated.

When the hot water stored in the hot water tank 1 is supplied to a water tap (not shown) via the hot water supply pipe 6, the amount of water in the hot water tank 1 decreases. Then, the control means 60 starts operation in the hot water storage mode. When the amount of water in the hot water tank 1 is reduced to a predetermined amount and the operation in the hot water storage mode is started, the valve element 33 is closed and the water supply valve 5 is opened. When the water supply valve 5 is opened, the water stored in the water receiving tank 3 is sent to the water heater 30 (refrigerant-water heat exchanger 52) through the water inflow pipe 31a. This water is heated by the hot water heater 30 (refrigerant-water heat exchanger 52) to become hot water. This hot water flows into the hot water tank 1 through the water outflow pipe 32 and is supplied to a water tap (not shown) through the hot water supply pipe 6.

Next, a determination operation for detecting a water break in the water heater 30 will be described.
Note that the operation related to the determination of the abnormality of water interruption is the same regardless of whether the operation mode is the circulation mode or the hot water storage mode, and here, the water stored in the hot water tank 1 is used as the hot water heater 30 (refrigerant-water). The operation of the hot water storage system 100 and the hot water heater 30 will be described taking the circulation mode of heating by the heat exchanger 52) as an example.

FIG. 3 is a flowchart showing determination processing for detecting water breakage in the water heater 30 according to Embodiment 1 of the present invention. FIG. 4 is a graph showing an example of the relationship between the flow rate of water flowing through the refrigerant-water heat exchanger 52 and the elapsed time according to the embodiment of the present invention.

Control means 60 starts operation of water heater 30 (step S1). When the operation of the water heater 30 is started, the flow rate detection means 40 periodically detects the flow rate of water flowing through the refrigerant-water heat exchanger 52 (for example, every 30 seconds). Further, the flow rate periodically detected by the flow rate detection unit 40 is stored in the storage unit 61 in a ring buffer format, for example. Therefore, the storage means 61 stores the flow rate of water flowing through the refrigerant-water heat exchanger 52 for a predetermined period going back from the present time.

In the control means 60, the state in which the flow rate of the water flowing through the refrigerant-water heat exchanger 52 detected by the flow rate detection means 40 is lower than the threshold value (hereinafter sometimes simply referred to as a flow rate reduction state) is set time T1 ( In this embodiment, it is determined whether or not to continue for 180 seconds (step S2). As shown in FIG. 4 (a), when the duration of the flow rate reduction state is less than the set time T1 (180 seconds) (step S2 in FIG. 3; Yes), the control means 60 determines that there is a water cutoff abnormality. Without returning to step S1, the operation of the water heater 30 is continued. On the other hand, as shown in FIG. 4B, when the duration time of the flow rate reduction state is equal to or longer than the set time T1 (180 seconds) (step S2 in FIG. 3; No), the control means 60 It is determined that an abnormality has occurred, and the process proceeds to step S3.

The set time T1 set in step S2 is a variable value according to the local connection piping path of the hot water storage system 100 and the pump used in the hot water storage system 100. In the first embodiment, the set time T1 is set within a range of 60 seconds to 180 seconds. Here, the grounds for setting the set time T1 will be described.

First, the lower limit (60 seconds) of the range of the set time T1 is based on the following two grounds.
The first ground is that a three-way valve is connected to the connection pipe of the heat pump water heater as shown in FIG. 8C, or a connection pipe of the heat pump water heater as shown in FIG. 8D. When two or more way valves are connected, there is a possibility that a temporary flow rate drop occurs as shown in FIG. 9 during valve operation such as flow path switching, and the flow rate detection means 40 may detect water breakage, It can be mentioned that the detection time of the flow rate drop at that time is less than 60 seconds. For this reason, if the lower limit of the range of the set time T1 is set to 60 seconds, it is possible to suppress erroneous determination that the temporary flow rate decrease during the valve operation of the three-way valve or the two-way valve is in a water-stopped state.
The second reason is that the flow rate detection means 40 may malfunction due to the influence of noise or the like, temporarily fail to detect the flow rate, and may detect a decrease in the flow rate. For example, the detection time is less than 60 seconds.
Based on these two grounds, the lower limit of the range of the set time T1 is 60 seconds.

Subsequently, the upper limit (180 seconds) of the range of the set time T1 is based on the following grounds.
When a pump (for example, a hot water supply pump 7 or a water supply pump 36) built in the hot water supply device 30 or used in the hot water storage system 100 using the hot water supply device 30 is continuously operated in a water-off state, the cooling effect of the pump by the fluid is obtained. It can no longer be obtained. Here, FIG. 5 is a graph showing an example of the relationship between the temperature of the pump and the operation elapsed time, and shows a graph when the pump is operated in a state where the flow rate is lower than the threshold value. As shown in FIG. 5, as the operation time of the pump with the flow rate decreased, the temperature of the components (for example, shaft and board) built in the pump rises and exceeds the guaranteed operating temperature. There is a risk of overheating and failure. Therefore, the maximum time for which a margin (for example, twice) can be ensured with respect to the time (for example, 360 seconds in FIG. 5) until the component built in the pump reaches the operation guarantee temperature is within the range of the set time T1. The upper limit is 180 seconds.

For the above reasons, the range of the set time T1 is set to 60 seconds or more and 180 seconds or less. The set time T1 is set for the control means 60 by a maintenance person or the like in the range of 60 seconds to 180 seconds. The setting of the setting time T1 in the control means 60 is realized by an arbitrary configuration such as rewriting a program executed by the CPU of the control means 60 or switching a signal to the control means 60 using an operation switch (not shown). .

The description of FIG. 3 is continued.
In step S3 of FIG. 3, the control unit 60 causes the notification unit 62 to notify that a water-stop abnormality has been detected. Moreover, in order to protect apparatuses, such as the feed pump 36 and the compressor 51, the control means 60 stops these apparatuses. As a stopping method, a command may be directly output from the control means 60 to each device, or may be stopped via another device. For example, the compressor 51 can be provided with a high-pressure shut-off device, and the compressor 51 can be stopped via the high-pressure shut-off device.

Further, as described above, the flow rate of the water flowing through the refrigerant-water heat exchanger 52 is periodically stored in the storage unit 61 (for example, every 30 seconds). When the controller 60 determines that the flow rate reduction state has continued for a set time T1 (180 seconds) or more and that the water heater 30 has stopped operating, the operation stop stored in the storage unit 61 is stopped. For example, the previous detected flow rate for 10 times is separately recorded in the storage means 61 as abnormal data (step S4). That is, in the first embodiment, the control means 60 and the storage means 61 function as the recording means of the present invention.

As described above, when the flow rate detection unit 40 detects the flow rate decrease, the control unit 60 determines whether or not the water flow is stopped according to the duration of the flow rate decrease state. It is possible to suppress erroneous detection of water stoppage by determining that the lowered state is water stoppage. If the flow rate is temporarily reduced, it is not determined that the water supply has stopped. Therefore, even if a temporary flow rate drop occurs within a range where the pump used in the hot water storage system 100 does not fail, the water heater 30 is operated without any trouble thereafter. it can. In addition, when the flow rate detection unit 40 detects the flow rate drop, the control unit 60 appropriately detects whether or not there is a water breakage abnormality according to the duration for which the flow rate drop is detected. It is possible to detect a water outage abnormality.

Further, in the first embodiment, when it is determined that the water supply is abnormal and the operation of the water heater 30 is stopped, the flow rate detected by the flow rate detection means 40 before the stop is recorded as abnormal data. For this reason, the person in charge of maintenance can confirm later whether the cause of the abnormal stop of the heat pump water heater is water stop, and the cause analysis of the abnormal stop becomes easy.

Embodiment 2. FIG.
In the first embodiment, the operation example in which the operation of the water heater 30 is stopped when the water break abnormality is detected has been described.
Here, for example, as shown in FIG. 6, when the water level 70 in the hot water tank 1 is lower than the connection portion of the water inflow pipe 31, or when the valve body 33 is out of order, The configuration related to the conveyance of water to the water heater 30 may be a cause of the water failure. If the operation of the water heater 30 is stopped in such a case, the operation of storing hot water in the hot water tank 1 is stopped, so that hot water runs out and the user may feel inconvenience. In addition, when the cause of the water cutoff abnormality is that the water level in the hot water storage tank 1 is lower than the connection part of the water inflow pipe 31 or the valve element 33 is broken, the operation of the water heater 30 itself is There is no problem, and if the water supplied from the water receiving tank 3 is supplied to the water heater 30, the water heater 30 may operate without any problem.

Therefore, in the second embodiment, the operation of the water heater 30 that solves such a problem will be described. In the second embodiment, the difference from the first embodiment will be mainly described.
FIG. 6 is a piping circuit diagram showing hot water storage system 100 according to Embodiment 2 of the present invention. In FIG. 6, the water level 70 in the hot water tank 1 is illustrated for the sake of explanation, but the configuration of the hot water storage system 100 shown in FIG. 6 is the same as that in FIG. A detector 2 is also provided.

FIG. 7 is a flowchart for explaining the operation of the water heater 30 according to Embodiment 2 of the present invention. The control means 60 of the second embodiment circulates water between the hot water heater 30 (refrigerant-water heat exchanger 52) and the hot water tank 1 as the operation mode of the hot water heater 30 as in the first embodiment. At least two operation modes: a circulation mode in which the water is heated and a hot water storage mode in which the hot water heated by the water heater 30 is stored in the hot water tank 1. Hereinafter, a description will be given with reference to FIG.

When the operation of the water heater 30 is started (step S10), the control means 60 determines whether the operation mode is the circulation mode, in other words, whether the operation mode is the hot water storage mode (step S11). If the water heater 30 is in the circulation mode (S11; Yes), the process proceeds to step S15. If the water heater 30 is in the hot water storage mode (S11; No), the process proceeds to step S12.

In step S12, when the flow rate detection unit 40 detects the flow rate drop, the control unit 60 determines whether or not the flow rate drop state continues for a set time T1 (180 seconds in the present embodiment) or more. When the duration time of the flow rate reduction state is less than the set time T1 (180 seconds) (S12; Yes), the control means 60 does not determine that the water supply is abnormal and returns to step S10 and continues the operation as it is. On the other hand, when the flow rate reduction state continues for the set time T1 (180 seconds) or longer (S12; No), it is determined that a water-stop abnormality has occurred, and the process proceeds to step S13.

In step S13, the control means 60 informs the notification means 62 that a water stop abnormality has been detected. Moreover, in order to protect apparatuses, such as the feed pump 36 and the compressor 51, the control means 60 stops these apparatuses. As a stopping method, a command may be directly output from the control means 60 to each device, or may be stopped via another device. For example, the compressor 51 can be provided with a high-pressure shut-off device, and the compressor 51 can be stopped via the high-pressure shut-off device. As described above, in the second embodiment, when water cut is detected during the operation in the hot water storage mode, the operation of the water heater 30 is stopped as in the first embodiment.

Further, as described in the first embodiment, the storage unit 61 periodically stores the flow rate of water flowing through the refrigerant-water heat exchanger 52 (for example, every 30 seconds). For example, the detected water flow rate for 10 times before stopping the operation of the water heater 30 stored in the storage unit 61 is separately recorded in the storage unit 61 as abnormal data (step S14). That is, in the second embodiment, the control means 60 and the storage means 61 function as the recording means of the present invention.

In step S15, when the flow rate detection unit 40 detects the flow rate drop, the control unit 60 determines whether or not the flow rate drop state continues for the set time T1 (180 seconds). When the duration of the flow rate reduction state is less than the set time T1 (180 seconds) (S15; Yes), the control means 60 returns to step S10 and continues the operation as it is without determining that the water supply is abnormal. On the other hand, when the flow rate reduction state continues for the set time T1 (180 seconds) or longer (S15; No), the process proceeds to step S16.

In step S16, the control means 60 informs the notification means 62 that a water stop abnormality has been detected during operation in the circulation mode. Moreover, in order to protect equipment, such as the feed pump 36 and the compressor 51, the control means 60 stops operation | movement of these equipment. As a stopping method, a command may be directly output from the control means 60 to each device, or may be stopped via another device. For example, the compressor 51 can be provided with a high-pressure shut-off device, and the compressor 51 can be stopped via the high-pressure shut-off device.

Further, as described in the first embodiment, the storage unit 61 periodically stores the flow rate of water flowing through the refrigerant-water heat exchanger 52 (for example, every 30 seconds). For example, the detected water flow rate for 10 times before stopping the operation of the water heater 30 stored in the storage unit 61 is separately recorded in the storage unit 61 as abnormal data (step S17).

After step S17, the control means 60 stands by until a standby time T2 (for example, 200 seconds) elapses, and thereafter, the operation is not permitted for the circulation mode, but the operation is permitted and started for the hot water storage mode ( The process proceeds to step S18) and step S19. In that case, the state which alert | reported by the alerting | reporting means 62 that the water stop state was detected during the operation | movement in circulation mode is maintained. Note that the value of the waiting time T2 in step S18 (200 seconds) is an example, and the equipment (for example, the water supply pump 36 and the compressor 51) heated due to the occurrence of a water shutoff is cooled to a temperature at which there is no operational problem. Set the time to be played.

In step S19, while executing the operation in the hot water storage mode, the control unit 60 determines whether or not the flow rate reduction state continues for 180 seconds when the flow rate detection unit 40 detects the flow rate reduction. If the detection time of the flow rate reduction state is less than the set time T1 (180 seconds) (S19; Yes), the control means 60 does not determine that the water supply is abnormal and continues the operation in the hot water storage mode in step S19. On the other hand, when the flow rate reduction state continues for the set time T1 (180 seconds) or longer (S19; Yes), the control means 60 determines that a water-breaking abnormality has occurred, and proceeds to step S13.

As described above, in the second embodiment, when the flow rate detection unit 40 detects a decrease in the flow rate, the control unit 60 determines whether or not the water is shut off according to the duration of the flow rate decrease state. Therefore, the same effect as in the first embodiment can be obtained.

Furthermore, in the second embodiment, even when hot water stored in the hot water storage tank 1 is circulated in the hot water heater 30 to detect water breakage during operation in the circulation mode and the operation of the hot water heater 30 is stopped, The operation in the hot water storage operation mode in which hot water heated by the hot water heater 30 is stored in the hot water storage tank 1 can be executed. For this reason, for example, when there is a shortage of water in the hot water tank 1 or when there is a defect in the water transfer path from the hot water tank 1 to the hot water heater 30, the hot water tank 1 is heated without stopping the operation of the hot water heater 30.

In the first and second embodiments, the example in which the water heater 30 is applied to the hot water storage system 100 having the hot water tank 1 has been described. However, the hot water is directly supplied from the water heater 30 to the water tap without using the hot water tank 1. You may do it. Moreover, each numerical value used for description in

Embodiment

1, 2 is an illustration, and does not limit this invention.

1 hot water tank, 2 temperature detector, 3 water receiving tank, 4 water supply pipe, 5 water supply valve, 6 hot water supply pipe, 7 hot water supply pump, 8 return pipe, 30 heat pump water heater, 31 water inflow pipe, 31a water inflow pipe, 32 water Outflow piping, 33 valve body, 34 valve body, 35 valve body, 36 water supply pump, 40 flow rate detection means, 50 heat pump cycle device, 51 compressor, 52 refrigerant-water heat exchanger, 53 decompression device, 54 evaporator, 55 Refrigerant inflow piping, 56 refrigerant outflow piping, 60 control means, 61 storage means, 62 notification means, 100 hot water storage system.

Claims

A heat pump cycle device in which a compressor, a refrigerant-water heat exchanger, a decompression device, and an evaporator are connected at least by piping, and heat is exchanged between the refrigerant and water in the refrigerant-water heat exchanger;
Flow rate detecting means for detecting the flow rate of water flowing through the refrigerant-water heat exchanger;
Control means for controlling the operation of the heat pump cycle device,
When the state where the flow rate of water detected by the flow rate detection unit is lower than a threshold value continues for a set time or longer, the control unit determines that the water supply is abnormal and stops the operation of the heat pump cycle device.
The state in which the flow rate of water detected by the flow rate detection unit is lower than a threshold value continues for a set time or longer, and when the operation of the heat pump cycle device is stopped, before the operation of the heat pump cycle device is stopped, 2. The heat pump water heater according to claim 1, further comprising recording means for recording the flow rate of water flowing through the refrigerant-water heat exchanger detected by the flow rate detection means as abnormal data.
The heat pump water heater according to claim 1 or 2, wherein the set time is a variable value.
The control means, as an operation mode of the heat pump cycle device, is a circulation mode in which water is circulated between a hot water storage tank for storing water to exchange heat with the refrigerant in the refrigerant-water heat exchanger and the refrigerant-water heat exchanger. And a hot water storage mode for storing in the hot water tank the water heat-exchanged with the refrigerant in the refrigerant-water heat exchanger,
The heat pump water heater according to any one of claims 1 to 3, wherein the control means switches to the hot water storage mode when it is determined that the water shutoff abnormality occurs while operating the heat pump cycle device in the circulation mode. .
When the control means determines that the water cutoff is abnormal, it notifies that the water cutoff is abnormal, and also notifies the fact that the water cutoff is abnormal after switching from the circulation mode to the hot water storage mode. The heat pump water heater of Claim 4 provided with these.
The heat pump water heater according to any one of claims 1 to 4, further comprising a notifying means for notifying that the water shutoff abnormality has occurred when the control means determines that the water shutoff abnormality has occurred.
The heat pump water heater according to any one of claims 1 to 6, wherein the set time ranges from 60 seconds to 180 seconds.
A heat pump water heater according to any one of claims 1 to 7,
A hot water storage system comprising a hot water storage tank for storing water to exchange heat with refrigerant in the refrigerant-water heat exchanger provided in the heat pump water heater.