JP7161882B2 - hot water system - Google Patents

Description

The technology disclosed in this specification relates to a hot water supply system.

Patent Document 1 discloses a tank that stores water, a heat pump that absorbs heat from the natural environment to heat water, circulation means that circulates water between the tank and the heat pump, and a combustion device that heats water by burning fuel gas. and a hot water supply system including a controller. In this hot water supply system, by setting the schedule for the boiling operation based on the history of hot water supply in the past, hot water supply of the high temperature required for hot water supply is actually started according to the lifestyle of the user. It can be stored in the tank at the last timing.

JP 2013-224762 A

After the last hot water is supplied in a day, the water in the tank is not used until the next day. Therefore, if most of the hot water stored in the tank remains at the end of the day, the loss due to heat radiation increases, resulting in a decrease in energy efficiency. Therefore, it is preferable that the amount of hot water remaining in the tank at the end of the day is as small as possible.

Generally, not much hot water is used after all those who are scheduled to bathe that day have finished bathing. In such a case, if the water in the tank is heated by the heat pump, the high-temperature water in the tank cannot be used up, resulting in a large amount of hot water remaining in the tank.

This specification provides a technique for solving the above problems. The present specification provides a technology capable of achieving energy saving in a hot water supply system including a heat pump.

The hot water supply system disclosed in the present specification includes a tank that stores water, a heat pump that heats the water by absorbing heat from the natural environment, circulation means that circulates water between the tank and the heat pump, and combustion of fuel gas to heat the water. It comprises a combustion device for heating, means for acquiring the number of people expected to take a bath, means for detecting the end of bathing, and a controller. The controller prohibits the heating of water by the heat pump on the day after a predetermined waiting time has elapsed after the number of times the bathing end is detected reaches the number of people scheduled to take a bath on the day.

According to the above configuration, when the number of times that the completion of bathing is detected reaches the number of people who plan to take a bath, that is, when it is determined that all the people who plan to take a bath have finished bathing, subsequent heating of water by the heat pump is prohibited. . By adopting such a configuration, it is possible to reduce the amount of hot water remaining in the final tank to save energy. The number of people scheduled to take a bath may be the number of all residents, or the number of residents scheduled to take a bath that day (for example, the number of residents who are staying at home). , may be the number of residents plus visitors. However, hot water may be supplied during the day even after all the people who are planning to take a bath have finished bathing. If there is almost no hot water left in the tank when all the people who plan to take a bath have finished bathing, and if the water heating by the heat pump is prohibited from that point onwards, the water heating by the combustion device will always be used for subsequent hot water supply. It will be necessary to do so, leading to a decrease in energy efficiency. Furthermore, according to the above configuration, since the water is heated by the heat pump until the waiting time has elapsed after all the people who are planning to take a bath have finished bathing, When there is almost no hot water left in the tank, water can be heated by the heat pump in preparation for subsequent hot water supply. A decrease in energy efficiency associated with the use of the combustion device can be suppressed.

The hot water supply system described above may further include means for specifying the season, and the standby time may be set according to the season.

Generally, in the summer, after all the people who plan to take a bath have finished bathing, there are few opportunities to use high-temperature water. Therefore, in the summer, if there is a long waiting time from when all the people planning to take a bath have finished bathing to when the heating of water by the heat pump is prohibited, the high temperature water in the tank cannot be used up, and eventually There is a risk that the amount of hot water remaining in the tank will increase. On the other hand, in winter, there are many opportunities to use high-temperature water even after all the people planning to take a bath have finished bathing. Therefore, in winter, if the waiting time from the end of bathing by all the people planning to take a bath to the prohibition of water heating by the heat pump is short, the high-temperature water in the tank will be used up, and the water will be reheated by the combustion device. The chance of heating increases, and energy efficiency may decrease. According to the above configuration, the standby time is set according to the season, so that after all the people who are planning to take a bath have finished bathing, heating of the water by the combustion device is suppressed, and finally the remaining hot water is stored in the tank. The amount can be reduced, and energy can be saved.

Another hot water supply system disclosed in this specification comprises a tank for storing water, a heat pump for absorbing heat from the natural environment to heat the water, a circulation means for circulating water between the tank and the heat pump, and combustion of fuel gas. It comprises a combustion device for heating water, means for acquiring the number of people expected to take a bath, means for detecting the end of bathing, means for acquiring the amount of hot water stored in the tank, and a controller. When the amount of hot water stored in the tank exceeds a predetermined necessary amount of hot water stored after the number of times of detecting the end of bathing on the day reaches the number of people scheduled to take a bath, the controller prohibits the subsequent heating of water by the heat pump on the day. .

According to the above configuration, when the number of times that the completion of bathing is detected reaches the number of people who plan to take a bath, that is, when it is determined that all the people who plan to take a bath have finished bathing, subsequent heating of water by the heat pump is prohibited. . By adopting such a configuration, it is possible to reduce the amount of hot water remaining in the final tank to save energy. The number of people scheduled to take a bath may be the number of all residents, or the number of residents scheduled to take a bath that day (for example, the number of residents who are staying at home). , may be the number of residents plus visitors. However, hot water may be supplied during the day even after all the people who are planning to take a bath have finished bathing. If there is almost no hot water left in the tank when all the people who are planning to take a bath have finished bathing, and if the water heating by the heat pump is prohibited from that point onwards, the subsequent hot water supply will always use the water by the combustion device. A need for heating arises, which leads to a decrease in energy efficiency. Furthermore , according to the above configuration, when the amount of hot water stored in the tank is less than the predetermined required amount of hot water after all the people who are planning to take a bath have finished bathing, the heat pump is allowed to heat the water. If there is almost no hot water left in the tank when bathing is finished, the water can be heated by the heat pump in preparation for subsequent hot water supply. A decrease in energy efficiency associated with the use of the combustion device can be suppressed.

The hot water supply system may further include a means for identifying the season, and the required hot water storage amount may be set according to the season.

Generally, in the summer, after all the people who plan to take a bath have finished bathing, there are few opportunities to use high-temperature water. Therefore, in the summer, if the amount of hot water stored in the tank is increased after all the people who plan to take a bath have finished bathing, the high temperature water in the tank cannot be used up completely, and the hot water remaining in the tank will eventually become unusable. The amount is likely to be large. On the other hand, in winter, there are many opportunities to use high-temperature water even after all the people planning to take a bath have finished bathing. Therefore, in winter, if the amount of hot water stored in the tank is reduced after all the people planning to take a bath have finished bathing, the hot water in the tank will be used up, increasing the chances of heating the water with a combustion device. and may reduce energy efficiency. According to the above configuration, the required amount of hot water to be stored is set according to the season. The amount of hot water to be stored can be reduced, and energy saving can be achieved.

1 is a diagram schematically showing the configuration of a hot water supply system 2 of an embodiment; FIG. FIG. 2 is a diagram schematically showing the time zones during which hot water is supplied in a typical household; 4 is a flowchart showing first heat pump operation processing executed by the controller 100 of the embodiment; 4 is a flowchart showing second heat pump operation processing executed by the controller 100 of the embodiment; 4 is a flowchart showing a hot water filling process executed by the controller 100 of the embodiment; 4 is a flowchart showing heat pump stop processing executed by the controller 100 of the embodiment. 4 is a flowchart showing heat pump stop processing executed by a controller 100 of a modified example;

(Example)
As shown in FIG. 1, the hot water supply system 2 according to the present embodiment includes a tank 10, a tank water circulation path 20, a tap water introduction path 30, a supply path 40, a heat pump 50, a combustion device 60, and a controller 100. and a remote controller 110 .

The heat pump 50 is a heat source that absorbs heat from the outside air, which is the natural environment, and heats the water in the tank water circulation path 20 . Although not shown, the heat pump 50 includes a refrigerant circuit that circulates a refrigerant (an alternative to Freon, such as R410A), an evaporator that exchanges heat between the outside air and the refrigerant, and a compression unit that compresses the refrigerant to a high temperature and high pressure. a condenser that exchanges heat between the water in the tank water circulation path 20 and the high-temperature and high-pressure refrigerant; and an expansion valve that reduces the pressure of the refrigerant after heat exchange to low-temperature and low-pressure. there is The heat pump 50 is also provided with an outside air temperature sensor 52 that measures the outside air temperature.

Tank 10 stores water heated by heat pump 50 . The tank 10 is a closed type and is covered with a heat insulating material. Water is stored in the tank 10 until it is full. In this embodiment, the capacity of the tank 10 is 100L. Thermistors 12 , 14 , 16 , 17 and 18 are attached to the tank 10 at predetermined intervals in the height direction of the tank 10 . Each thermistor 12, 14, 16, 17, 18 measures the temperature of the water at its mounting location. For example, each thermistor 12, 14, 16, 17, 18 measures the temperature of water at positions 6L, 12L, 30L, 50L, 70L from the top of the tank 10, respectively.

The tank water circulation path 20 has an upstream end connected to the bottom of the tank 10 and a downstream end connected to the top of the tank 10 . A circulation pump 22 is interposed in the tank water circulation path 20 . The circulation pump 22 sends out the water in the tank water circulation path 20 from the upstream side to the downstream side. Also, the tank water circulation path 20 passes through a heat exchanger (not shown) of the heat pump 50 . Therefore, when the heat pump 50 is operated, the water in the tank water circulation path 20 is heated by the heat exchanger of the heat pump 50 . Therefore, when the circulation pump 22 and the heat pump 50 are operated, the water in the lower part of the tank 10 is heated by the heat pump 50 and the heated water is returned to the upper part of the tank 10 . That is, the tank water circulation path 20 is a water path for storing heat in the tank 10 . A thermistor 24 is interposed upstream of the heat pump 50 in the tank water circulation path 20 . A thermistor 24 is led out from the bottom of the tank 10 and measures the temperature of the water before passing through the heat pump 50 . The thermistor 24 may be provided in the tank water circulation path 20 closer to the heat pump 50 than the circulation pump 22, or may be provided in the tank water circulation path 20 closer to the tank 10 than the circulation pump 22. .

The tap water introduction channel 30 is connected to a tap water supply source 31 at its upstream end. A thermistor 32 is interposed in the tap water introduction passage 30 . The thermistor 32 measures the temperature of tap water. The downstream side of the tap water introduction channel 30 branches into a first introduction channel 30a and a second introduction channel 30b. A downstream end of the first introduction path 30 a is connected to the lower portion of the tank 10 . A downstream end of the second introduction path 30 b is connected to the middle of the supply path 40 . A mixing valve 42 is provided at the connection portion between the downstream end of the second introduction passage 30b and the supply passage 40 . The mixing valve 42 adjusts the amount of water flowing in the supply path 40 mixed with the water in the second introduction path 30b.

The supply path 40 is connected to the top of the tank 10 at its upstream end. A combustion device 60 is interposed in the supply passage 40 on the downstream side of the connection with the second introduction passage 30b. A thermistor 44 is interposed in the supply passage 40 on the downstream side of the combustion device 60 . A thermistor 44 measures the temperature of the water supplied. Combustion device 60 heats water by combustion of fuel gas. The combustion device 60 heats the water in the supply path 40 so that the temperature of the water measured by the thermistor 44 matches the hot water supply set temperature. The downstream end of the supply path 40 is connected to a hot water supply location (eg, a kitchen faucet (not shown), a shower 54 or a faucet 56 in a bathroom 48, etc.). A hot water filling valve 46 for filling the bathtub 58 of the bathroom 48 with hot water is provided at the downstream end of the supply path 40 . The bathroom 48 is provided with a human sensor 62 for detecting the presence or absence of a bather.

Controller 100 is electrically connected to each component and controls the operation of each component. A remote controller 110 is connected to the controller 100 . Remote controller 110 can display various types of information related to hot water supply system 2 . Further, remote control 110 can accept various operation inputs related to hot water supply system 2 . The user of the hot water supply system 2 can, via the remote control 110, set the hot water supply temperature, which is the temperature of the water to be supplied to the shower 54, the faucet 56, etc., the bath set temperature, which is the temperature of the water to be supplied to the bathtub 58, and the hot water supply to the bathtub 58. The completion time of hot water filling, which is the time to complete the filling, can be set.

Next, the operation of the hot water supply system 2 of this embodiment will be described. The hot water supply system 2 can perform a boiling operation, a hot water supply operation, and a hot water filling operation. In this specification, both the hot water supply operation and the hot water filling operation of the hot water supply system 2 are referred to as hot water supply by the hot water supply system 2 . Each operation will be described below.

(boiling operation)
The boiling operation is an operation in which the heat pump 50 heats the water in the tank 10 . When the controller 100 instructs the execution of the boiling operation, the heat pump 50 is activated and the circulation pump 22 is activated. When the circulation pump 22 operates, the water in the tank 10 circulates through the tank water circulation path 20 . That is, the water existing in the lower part of the tank 10 is introduced into the tank water circulation path 20, and when the introduced water passes through the heat exchanger in the heat pump 50, it is heated by the heat of the refrigerant, and the heated water It is returned to the upper part of the tank 10. Thereby, high-temperature water is stored in the tank 10 . A thermal stratification is formed inside the tank 10, in which a layer of hot water is layered on top of a layer of cold water.

(hot water supply operation)
The hot water supply operation is an operation for supplying water at a hot water supply set temperature to a hot water supply location. The hot water supply operation can also be performed during the boiling operation described above. When the hot water supply portion such as the shower 54 or the faucet 56 is opened, the water pressure from the tap water supply source 31 causes the tap water to flow into the lower portion of the tank 10 from the tap water introduction passage 30 (first introduction passage 30a). At the same time, the water in the upper part of the tank 10 is supplied to the hot water supply point via the supply channel 40 .

When the temperature of the water supplied from the tank 10 to the supply path 40 (that is, the temperature measured by the thermistor 12) is higher than the set hot water supply temperature, the controller 100 opens the mixing valve 42 and supplies water from the second introduction path 30b. Tap water is introduced into the channel 40 . Therefore, the high-temperature water supplied from the tank 10 and the low-temperature tap water supplied from the second introduction passage 30b are mixed within the supply passage 40 . The controller 100 adjusts the opening degree of the mixing valve 42 so that the temperature of the water supplied to the hot water supply point matches the hot water supply set temperature. On the other hand, the controller 100 activates the combustion device 60 when the temperature of the water supplied from the tank 10 to the supply path 40 is lower than the hot water supply set temperature. Accordingly, water passing through the supply passage 40 is heated by the combustion device 60 . The controller 100 controls the output of the combustion device 60 so that the temperature of the water supplied to the hot water supply location matches the hot water supply set temperature.

(Hot water filling operation)
The hot water filling operation is an operation for supplying water at the bath set temperature to the bathtub 58 . The hot water filling operation can also be performed during the above boiling operation. When the hot water filling start time based on the hot water filling completion time set by the remote controller 110 comes, the controller 100 opens the hot water filling valve 46 . As a result, water adjusted to the bath set temperature is supplied to the bathtub 58 in the same manner as in the hot water supply operation.

(Learning control of boiling-up operation)
FIG. 2 is a diagram schematically showing time periods during which hot water is supplied in a day. In this embodiment, 24 hours starting at 2:00 is used as the unit time for specifying one day.

Generally, for example, hot water is first supplied from 6:00 to 7:00 (6:00 in the example of FIG. 2). The first hot water supply is, for example, hot water supply for preparing breakfast or washing the face. In the first hot water supply, hot water of about 5 L to 20 L is supplied. After that, for example, hot water is supplied for the second time from 11:00 to 12:00 (11:00 in the example of FIG. 2). The second hot water supply is, for example, hot water supply for preparing lunch. Even in the second hot water supply, hot water of about 5L to 20L is supplied. After that, for example, hot water is supplied for the third time at 20:00 (20:00 in the example of FIG. 2). The third hot water supply is a hot water filling operation to the bathtub 58 . In the hot water filling operation, hot water of about 150L to 180L is supplied. After that, for example, the final hot water supply is performed from 23:00 to 0:00 (approximately 23:00 in the example of FIG. 2). The final hot water supply is, for example, hot water supply for brushing teeth. In the last hot water supply, hot water of about 5L to 10L is supplied. The final supply of hot water ends at around 0:00.

In this embodiment, every time hot water is supplied, the controller 100 stores the time when hot water supply started, the time when hot water supply ended, and the amount of hot water supplied indicating the amount of hot water used for hot water supply. remember as In addition, every time the human sensor 62 detects a bather in the bathroom 48, the controller 100 detects the time when bathing started (the time when the state where the bather was not detected was switched to the state where the bather was detected). ) and the time when the bathing ended (the time when the state where the bather was detected was switched to the state where the bather was not detected) is stored as the bathing record. The controller 100 stores the hot water supply performance and the bathing performance for one day as an operation history for one day. In this embodiment, the controller 100 stores the driving history for each day of a past predetermined period (for example, one month).

Next, the processing executed by the controller 100 every 24 hours (every time the time reaches 2:00) will be described. The controller 100 newly stores the driving history of the previous day every 24 hours.

Next, controller 100 identifies the earliest time among the times (hot water supply start time) at which hot water supply was first started in the past 7 days from the operation history for the past 7 days. This time is hereinafter referred to as "hot water supply start time S1". For example, the controller 100 identifies 6:00 as the hot water supply start time S1 (see FIG. 2).

Further, the controller 100 identifies the largest amount of hot water supplied from the hot water supply start time to before the start of hot water replenishment in the past seven days from the operation history for the past seven days. Hereinafter, this hot water supply amount will be referred to as "first hot water supply amount Q1". For example, the controller 100 identifies 30L as the first hot water supply amount Q1.

In addition, the controller 100 identifies the earliest time among the times when the hot water filling operation was started (hot water filling start time) in the past seven days from the operation history for the past seven days. This time is hereinafter referred to as "hot water filling start time B1". As described above, in this embodiment, the hot water filling operation is preset to start at 20:00 every day. For example, the controller 100 specifies 20:00 as the hot water filling start time B1 (see FIG. 2).

Further, controller 100 identifies the latest time of the last hot water supply end time (hot water supply end time) in the past seven days from the operation history for the past seven days. This time is hereinafter referred to as "hot water supply end time G1". For example, the controller 100 specifies 0:00 as the hot water supply end time G1 (see FIG. 2).

Further, the controller 100 specifies the first predetermined time α based on the temperature TW (that is, the tap water temperature) measured by the thermistor 32 and the first hot water supply amount Q1. Also, the controller 100 specifies the second predetermined time β and the third predetermined time γ based on the temperature TW measured by the thermistor 32 (that is, the temperature of the tap water).

As shown in FIG. 2, when the temperature TW is 21° C. or higher, the controller 100 specifies “20 minutes” as the first predetermined time α. When the temperature TW is 13° C. or more and less than 21° C., the controller 100 specifies “30 minutes” as the first predetermined time α. When the temperature TW is less than 13° C., the controller 100 specifies “45 minutes” as the first predetermined time α. The controller 100 specifies a shorter time as the first predetermined time α as the temperature TW is higher.

Further, as shown in FIG. 2, when the first hot water supply amount Q1 is less than 12 L, the controller 100 specifies "5 minutes" as the additional time of the first predetermined time α. When the first hot water supply amount Q1 is equal to or greater than 12 L and less than 30 L, the controller 100 specifies "10 minutes" as the additional time for the first predetermined time α. When the first hot water supply amount Q1 is equal to or greater than 30 L, the controller 100 specifies "15 minutes" as the additional time for the first predetermined time α. The controller 100 specifies a shorter time as the addition time of the first predetermined time α as the first hot water supply amount Q1 decreases.

Similarly, as shown in FIG. 2, when the temperature TW is 21° C. or higher, the controller 100 specifies “40 minutes” as the second predetermined time β. When the temperature TW is 13° C. or more and less than 21° C., the controller 100 specifies “50 minutes” as the second predetermined time β. When the temperature TW is less than 13° C., the controller 100 specifies “60 minutes” as the second predetermined time β. The controller 100 specifies a shorter time as the second predetermined time β as the temperature TW is higher.

Furthermore, similarly, as shown in FIG. 2, when the temperature TW is 21° C. or higher, the controller 100 specifies “80 minutes” as the third predetermined time period γ. When the temperature TW is 13° C. or more and less than 21° C., the controller 100 specifies “50 minutes” as the third predetermined time γ. When the temperature TW is less than 13° C., the controller 100 specifies “40 minutes” as the third predetermined time γ. The controller 100 specifies a longer time as the third predetermined time γ as the temperature TW is higher.

Next, the controller 100 identifies a first heat pump operation time S0 that is a time earlier than the hot water supply start time S1 by the identified first predetermined time α. In this embodiment, the controller 100 starts a first heat pump operation process (see FIG. 3), which will be described later, when the first heat pump operation time S0 arrives.

In addition, the controller 100 specifies a second heat pump operation time B0, which is a time before the specified second predetermined time β from the hot water filling start time B1. In this embodiment, when the second heat pump operation time B0 arrives, the controller 100 starts a second heat pump operation process (see FIG. 4), which will be described later.

Further, the controller 100 specifies the heat pump stop time G0, which is the specified third predetermined time γ before the hot water supply end time G1. In this embodiment, the controller 100 starts heat pump stop processing (see FIG. 6), which will be described later, after completing the second heat pump operation processing.

(First heat pump activation process)
FIG. 3 is a flow chart showing the details of the first heat pump operation process executed by the controller 100. As shown in FIG. As described above, when the first heat pump operation time S0 arrives, the controller 100 starts the process of FIG.

First, in S10, the controller 100 selects, from among the thermistors 12, 14, 16, 17, and 18 attached to the tank 10, the thermistor corresponding to the first hot water supply amount Q1. In this embodiment, the first hot water supply amount Q1 is 30L, so the controller 100 selects the thermistor 16 corresponding to 30L.

In subsequent S12, the controller 100 determines whether the temperature measured by the thermistor 16 selected in S10 (that is, the water temperature at the position 30L from the top of the tank 10) is higher than a predetermined threshold TA.

In this embodiment, the predetermined threshold value TA is "boiling set temperature -10°C". The boiling set temperature is, for example, 47°C. Therefore, the predetermined threshold TA is 37° C., for example. If it is determined YES in S12, at least the water temperature at the position 30L from the top of the tank 10 is higher than the threshold TA (for example, 37°C). As described above, a thermal stratification is formed inside the tank 10 in which a layer of high temperature water is stacked on a layer of low temperature water. Therefore, when the determination in S12 is YES, high-temperature water close to the set boiling temperature (for example, 47° C.) is stored between the 30L position of the tank 10 and the top of the tank. That is, when it is determined as YES in S12, the tank 10 stores the amount of hot water (approximately 5 L to 20 L) required for the first hot water supply scheduled to be performed at a time near the hot water supply start time S1. means that When it is determined YES in S12, the process proceeds to S18. On the other hand, when it is determined as NO in S12, the process proceeds to S14.

In S14, controller 100 determines whether heat pump 50 is in operation. If the heat pump 50 is operating, the controller 100 determines YES in S14 and returns to S12. In this case, the controller 100 continues the boiling operation in which the heat pump 50 heats the water in the tank 10 . On the other hand, if the heat pump 50 is not operating, the controller 100 determines NO in S14 and proceeds to S16.

At S<b>16 , the controller 100 activates the heat pump 50 . The controller 100 also rotates the circulation pump 22 . That is, the controller 100 starts the above boiling operation. As a result, water existing in the lower part of the tank 10 is introduced into the tank water circulation path 20 , the introduced water is heated by the heat pump 50 , and the heated water is returned to the upper part of the tank 10 . Thereby, high-temperature water is stored in the tank 10 . After activating the heat pump 50 in S16, the process returns to S12, and the controller 100 confirms that the temperature measured by the thermistor 16 is higher than a predetermined threshold value TA (that is, the tank 10 is filled with the first hot water amount Q1 of water of a predetermined amount). The water temperature is higher than the threshold TA). If the temperature measured by the thermistor 16 is higher than the predetermined threshold value TA (YES in S12), the process proceeds to S18.

At S<b>18 , the controller 100 stops the heat pump 50 and circulation pump 22 . As described above, if the determination in S12 is YES, this is because the tank 10 already stores the amount of hot water required for the first hot water supply (the first hot water supply amount Q1 (30 L)). be.

After starting the first heat pump operation process in FIG. supplied to the site. As described above, in the hot water supply system 2 of the present embodiment, the amount of hot water required for hot water supply can be stored in the tank 10 at the hot water supply start time S1. That is, by operating the heat pump 50 only during the first predetermined time period α, the amount of high-temperature water required for hot water supply can be stored in the tank 10 at the hot water supply start time S1. It is time to become

(Second heat pump activation process)
FIG. 4 is a flow chart showing the details of the second heat pump operation process executed by the controller 100. As shown in FIG. As described above, when the second heat pump operation time B0 arrives, the controller 100 starts the process of FIG.

First, in S30, the controller 100 determines whether the temperature measured by the thermistor 24 (that is, the temperature of water derived from the lower portion of the tank 10 and before passing through the heat pump 50) is higher than a predetermined threshold TB (that is, (whether or not the tank 10 is fully charged) is determined. In this embodiment, the predetermined threshold value TB is "boiling set temperature -5°C". When the set boiling temperature is 47°C, the predetermined threshold TB is 42°C, for example. When it is judged as YES in S30, it progresses to S38. On the other hand, when it is judged as NO in S30, it progresses to S32.

At S<b>32 , the controller 100 activates the heat pump 50 . The controller 100 also rotates the circulation pump 22 . That is, the controller 100 starts the above boiling operation. Note that if the heat pump 50 and the circulation pump 22 are already operating at the time of S32, the controller 100 causes the heat pump 50 and the circulation pump 22 to continue operating. After completing S32, the process proceeds to S34.

On the other hand, in S38, the heat pump 50 and the circulation pump 22 are stopped. As described above, if the determination in S30 is YES, the tank 10 is fully charged. Therefore, it is not necessary to operate the heat pump 50 and the circulation pump 22 any more. After completing S38, the process proceeds to S34.

At S34, the controller 100 determines whether or not the hot water filling start time B1 has arrived. If it is determined YES in S34, the process proceeds to S36 to start the hot water filling process (see FIG. 5). On the other hand, if NO in S34, the process returns to S30.

In this embodiment, when the second heat pump operation process of FIG. 4 is started, if the water of the boiling set temperature is not sufficiently stored in the tank 10, the heat pump 50 is operated in the above S32. After that, the hot water filling start time B1 arrives before the tank 10 reaches the full state (YES in S34). That is, in this embodiment, when the controller 100 operates the heat pump 50 at the second heat pump operation time B0 (S32), the temperature measured by the thermistor 24 at the hot water filling start time B1 falls below the predetermined threshold TB. The second predetermined time β is specified so that

(Hot water filling treatment)
As described above, when the hot water filling start time B1 arrives, the controller 100 starts the hot water filling process in S36. FIG. 5 is a flow chart showing the contents of the hot water filling process. In this embodiment, when the hot water filling start time B1 arrives, the hot water filling process is automatically started. Hot water filling may be started.

In S50 of FIG. 5, the controller 100 starts the hot water filling operation. That is, the controller 100 opens the hot water filling valve 46 and starts supplying water to the bathtub 58 . Next, in S52, the controller 100 determines whether the heat pump 50 is in operation. As described above, if the tank 10 is not in a full state when the hot water filling start time B1 arrives, the heat pump 50 continues to operate. In that case, the controller 100 determines YES in S52 and proceeds to S58. On the other hand, if the tank 10 is fully charged when the hot water filling start time B1 arrives, the heat pump 50 is stopped. In that case, the controller 100 determines NO in S52 and proceeds to S54.

In S54, the controller 100 monitors whether the temperature measured by the thermistor 18 is equal to or less than a predetermined threshold TA. Alternatively, the controller 100 monitors whether the temperature measured by the thermistor 24 falls below a predetermined threshold TA. If YES in S54, the process proceeds to S56. In S<b>56 , the controller 100 operates the heat pump 50 and rotates the circulation pump 22 .

In S58, the controller 100 monitors whether the temperature measured by the thermistor 12 (that is, the water temperature at the position 6L from the top of the tank 10) becomes equal to or lower than the bath set temperature. If it is determined YES in S58, it means that the amount of high-temperature water (water having a temperature higher than the bath set temperature) stored in the tank 10 has decreased to 6L or less. Hereinafter, this state may be referred to as a "hot water shortage state". In this embodiment, hot water of 150L to 180L is required in the hot water filling operation. As described above, in this embodiment, the capacity of the tank 10 is 100 L, so the hot water shortage state (YES in S58) always occurs during the hot water refilling operation. If it is determined YES in S58 (that is, if the hot water has run out), the process proceeds to S60.

At S60, the controller 100 activates the combustion device 60. FIG. Also in this case, the controller 100 continues to operate the heat pump 50 and the circulation pump 22 . As a result, water heated by the heat pump 50 and the combustion device 60 is supplied to the bathtub 58 .

Next, at S62, the controller 100 monitors completion of the hot water filling operation. After supplying a predetermined amount (for example, 150 L) of water to the bathtub 58, the controller 100 determines YES in S62 and proceeds to S64.

At S64, the controller 100 stops the combustion device 60 operated at S60. Also in this case, the controller 100 continues to operate the heat pump 50 and the circulation pump 22 for a predetermined time. When S64 ends, the hot water filling process in FIG. 5 ends. At the same time, the process of FIG. 4 also ends. As described above, in the hot water supply system 2 of the present embodiment, at the hot water filling start time B1, the tank 10 can store a part of the necessary amount of hot water for hot water filling. That is, during the second predetermined time β, by operating the heat pump 50 only during that time, it is possible to store the necessary amount of high-temperature water in the tank 10 at the hot water filling start time B1. It is time to become

Further, as described above, when the controller 100 activates the heat pump 50 at the second heat pump activation time B0 (S32), the temperature measured by the thermistor 24 becomes less than the predetermined threshold TB at the hot water filling start time B1. , the second predetermined time β is specified. Therefore, if the tank 10 is not fully charged when the hot water filling start time B1 arrives, the heat pump 50 continues to operate even after the water supply to the bathtub 58 is started (S50 in FIG. 5). (YES in S52 of FIG. 5). In this case, hot water can be supplied to the bathtub 58 while water is heated by the heat pump 50 and stored in the tank 10 . On the other hand, if the heat pump 50 is stopped at the hot water filling start time B1 (NO in S52 of FIG. 5), the heat pump 50 needs to be reactivated later, which takes time (S56 of FIG. 5). Further, if the heat pump 50 continues to operate at the hot water filling start time B1 (YES in S52 of FIG. 5), if the heat pump 50 is stopped at the hot water filling start time B1 ( Compared to NO in S52), it is possible to suppress frequent stopping and restarting of the heat pump 50 . That is, it is possible to reduce the loss due to the stop and restart of the heat pump 50, to improve the energy efficiency, and to suppress the deterioration of the durability of the heat pump 50.

(Heat pump stop processing)
FIG. 6 is a flow chart showing the details of the heat pump stop processing executed by the controller 100. As shown in FIG. As described above, when the second heat pump operation process ends, the controller 100 starts the process of FIG.

First, in S70, the controller 100 specifies the number of people who plan to take a bath. The number of people expected to take a bath can be specified by various methods. For example, if the user has previously registered the number of people expected to take a bath via the remote control 110 , the controller 100 acquires the number of people expected to take a bath from the remote control 110 . The number of people scheduled to take a bath registered by the user in the remote control 110 may be the actual number of people who live there, or the number of people who take a bath among the residents, for example, the number of people who are at home among the residents. Alternatively, it may be the number of residents and visitors who take a bath. The number of people living at home may be specified, for example, by using a wireless transmitter and a wireless receiver that are installed in the house and can communicate with remote controller 110, and that reflect radio waves from people living at home. Alternatively, if the controller 100 can communicate with other household appliances such as air conditioners and the number of occupants has already been specified in the other household appliances, the controller 100 can communicate with the other household appliances. The number of residents may be acquired from and specified as the planned number of people to take a bath. Alternatively, the controller 100 may calculate the number of bathing completion times for each day based on the driving history for the past 7 days, and identify the highest number of bathing completion times in the past 7 days as the expected number of people to take a bath.

Next, in S72, the controller 100 determines whether or not the end of bathing has been detected. For example, the controller 100 determines that the bathing is finished when the motion sensor 62 stops detecting the presence of the bather after the motion sensor 62 detects the presence of the bather. When it is judged as YES in S72, it progresses to S74. On the other hand, when it is determined as NO in S72, the process proceeds to S76.

In S74, the controller 100 determines whether or not the number of times bathing has ended on the day has reached the planned number of people to take a bath. When it is judged as YES in S74, it progresses to S78. On the other hand, when it is judged as NO in S74, it progresses to S76.

At S76, the controller 100 determines whether or not the heat pump stop time G0 has arrived. When it is judged as YES in S76, it progresses to S80. On the other hand, if NO is determined in S76, the process returns to S72.

At S78, the controller 100 waits until a predetermined waiting time elapses. The standby time is, for example, 30 minutes. After the standby time has elapsed, the process proceeds to S80.

In S80, the controller 100 prohibits the heat pump 50 from operating. That is, if the heat pump 50 is operating at the time of S80, the controller 100 stops the heat pump 50. FIG. After S80, the controller 100 prohibits the operation of the heat pump 50 until the next day. Therefore, the hot water supply operation to be performed later on the day is performed using the high-temperature water remaining in the tank 10 at the time of S80, and when the tank 10 runs out of hot water, the heating by the combustion device 60 is performed. is done.

In the heat pump stop processing of FIG. 6, when the heat pump stop time G0, which is the time earlier than the hot water supply end time G1 estimated from the past operating results by the third predetermined time γ, arrives, the heat pump 50 is operated thereafter. is prohibited. Therefore, in the hot water supply system 2 of this embodiment, it is possible to prevent an excessive amount of hot water from being stored in the tank 10 when all hot water supply for the day is completed. That is, during the third predetermined time period γ, the heat pump 50 is not operated, so that the tank 10 is not excessively filled with high-temperature water at the hot water supply end time G1. It is time to become

In the heat pump stop processing of FIG. 6, even before the heat pump stop time G0, it is determined that the bathing of all the people who are planning to take a bath has been finished when the number of bathing completion times of the day reaches the number of people who plan to take a bath. Then, when the standby time has elapsed from that time, the heat pump 50 is prohibited from operating on that day and thereafter. Usually, after all the people who plan to take a bath finish bathing, it is not necessary to supply so much hot water. Therefore, in the hot water supply system 2 of this embodiment, it is possible to prevent an excessive amount of hot water from being stored in the tank 10 when all hot water supply for the day is completed.

In addition, in the process of FIG. 6, the standby time of S78 may be set according to the season. For example, the standby time may be set to a long time (eg, 1 hour) in winter, and set to a short time (eg, 15 minutes) in summer. The controller 100 may identify the season based on, for example, the outside temperature measured by the outside temperature sensor 52 and/or the tap water temperature measured by the thermistor 32 . Alternatively, the controller 100 may incorporate a clock and calendar to specify the season from the current calendar day.

Note that if S74 is determined to be YES, S78 may be skipped and the process may proceed to S80. In this case, when it is determined that all the people who plan to take a bath have finished bathing, the heat pump 50 is prohibited from operating thereafter without waiting for the elapse of the waiting time.

Note that the controller 100 may execute the heat pump stop processing of FIG. 7 instead of the heat pump stop processing of FIG. The heat pump stop processing of FIG. 7 is substantially the same as the heat pump stop processing of FIG. 6, but the processing when it is determined as YES in S74 is different from the heat pump stop processing of FIG.

In the heat pump stop processing of FIG. 7, when it is judged as YES in S74, it progresses to S82. In S82, the controller 100 acquires the amount of hot water stored in the tank 10, and determines whether or not the amount of hot water stored in the tank 10 is equal to or greater than a predetermined required amount of hot water. The amount of hot water stored in the tank 10 is calculated, for example, based on the water temperature distribution in the height direction of the tank 10 detected by thermistors 12, 14, 16, 17, and 18 and the tap water temperature detected by the thermistor 32. can do. The necessary amount of hot water to be stored is the amount of hot water to be supplied that is expected to be used after all the people who plan to take a bath finish bathing. The controller 100 may, for example, set the required hot water storage amount to a predetermined value (eg, 10 L). Alternatively, the controller 100 may set the required hot water storage amount according to the season. For example, the required hot water storage amount may be set large (eg, 15 L) in winter, and the required hot water storage amount may be set small (eg, 5 L) in summer. The controller 100 may identify the season based on, for example, the outside temperature measured by the outside temperature sensor 52 and/or the tap water temperature measured by the thermistor 32 . Alternatively, the controller 100 may incorporate a clock and calendar to specify the season from the current calendar day. Alternatively, the controller 100 may set the required hot water storage amount based on the past operating history. For example, the controller 100 identifies, from the operation history for the past 7 days, the hot water supply amount that is the largest among the hot water supply amounts after the last bathing of the day is completed in the past 7 days, and the hot water supply that has been identified The supply amount may be set to the required hot water storage amount.

If it is determined YES in S82, the controller 100 proceeds to S80 and prohibits the heat pump 50 from operating.

If NO is determined in S82, the process proceeds to S84. In S84, the controller 100 determines whether or not the heat pump stop time G0 has arrived. If the determination in S84 is YES, the controller 100 proceeds to S80 and prohibits the heat pump 50 from operating. On the other hand, if NO is determined in S84, the process returns to S82.

In the heat pump stop processing of FIG. 7, even before the heat pump stop time G0 arrives, after the number of bathing completion times on the day reaches the number of people planning to take a bath, the hot water storage amount in the tank 10 exceeds the required hot water storage amount. operation of the heat pump 50 on that day and thereafter is prohibited. As a result, it is possible to prevent hot water from being stored in the tank 10 more than necessary after all the people who plan to take a bath have finished bathing. can be prevented from accumulating excessively.

In the heat pump stop processing of FIGS. 6 and 7, the identification of the number of people expected to take a bath in S70 may be repeatedly performed until the operation of the heat pump 50 is prohibited in S80, thereby sequentially updating the number of people expected to take a bath. In this case, the updated number of people scheduled to take a bath may be less than the original number of people scheduled to take a bath, and even if there is no change in the number of times bathing ends on the day, the decrease in the number of people scheduled to take a bath satisfies the condition of S74. There is Therefore, in the case of such a configuration, when the number of people scheduled to take a bath decreases due to the updating of the number of people scheduled to take a bath, the process of S74 is executed at that time. As a result, when the number of bathing completion times on the day has reached the number of people scheduled to take a bath after updating, subsequent processing can be executed promptly.

In the above description, controller 100 may specify the average hot water supply start time for the past seven days as hot water supply start time S1 from the operation history for the past seven days. Similarly, the controller 100 may specify, as the hot water filling start time B1, the average time of the hot water filling start times in the past seven days from the operation history for the past seven days. Further, controller 100 may specify the average hot water supply end time for the past seven days as hot water supply end time G1 from the operation history for the past seven days. Further, the controller 100 may specify the average number of bathing completion times in the past seven days as the number of people scheduled to take a bath, from the driving history for the past seven days. Further, the controller 100 may specify the average hot water supply amount after the last bathing in the past 7 days as the required hot water storage amount from the operation history for the past 7 days.

In the above embodiment, the hot water supply system 2 uses the human sensor 62 to detect the presence or absence of a bather. For example, a water level sensor that detects the water level of the bathtub 58 may be provided, and the controller 100 may detect the presence or absence of a bather based on fluctuations in the water level detected by the water level sensor.

Although the embodiments of the present invention have been described in detail above, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.

The technical elements described in this specification or in the drawings exhibit technical utility either singly or in various combinations, and are not limited to the combinations described in the claims as filed. In addition, the techniques exemplified in this specification or drawings can simultaneously achieve a plurality of purposes, and achieving one of them has technical utility in itself.

2: hot water supply system 10: tank 12: thermistor 14: thermistor 16: thermistor 17: thermistor 18: thermistor 20: tank water circulation path 22: circulation pump 24: thermistor 30: tap water introduction path 30a: first introduction path 30b: second Introduction path 31 : Tap water supply source 32 : Thermistor 40 : Supply path 42 : Mixing valve 44 : Thermistor 46 : Hot water supply valve 48 : Bathroom 50 : Heat pump 52 : Outside air temperature sensor 54 : Shower 56 : Coolant 58 : Bathtub 60 : Combustion Device 62: human sensor 100: controller 110: remote control

Claims (4)

a tank to store water and
a heat pump that absorbs heat from the natural environment to heat water;
a circulation means for circulating water between the tank and the heat pump;
a combustion device for heating water by combustion of fuel gas;
a means for acquiring the number of people scheduled to take a bath;
means for detecting the end of bathing;
has a controller
A hot water supply system , wherein a controller prohibits heating of water by a heat pump on the day after a predetermined waiting time has passed after the number of times that the number of bathing completions is detected reaches the number of people scheduled to take a bath on the day . It also has a means of identifying the season,
2. The hot water supply system according to claim 1 , wherein the standby time is set according to the season. a tank to store water and
a heat pump that absorbs heat from the natural environment to heat water;
a circulation means for circulating water between the tank and the heat pump;
a combustion device for heating water by combustion of fuel gas;
a means for acquiring the number of people scheduled to take a bath;
means for detecting the end of bathing;
means for obtaining the amount of hot water stored in the tank;
has a controller
When the amount of hot water stored in the tank exceeds a predetermined necessary amount of hot water stored after the number of times of detecting the end of bathing on the day reaches the number of people scheduled to take a bath, the controller prohibits the subsequent heating of water by the heat pump on the day. , hot water system. It also has a means of identifying the season,
4. The hot water supply system according to claim 3 , wherein the required hot water storage amount is set according to the season.

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