KR101572439B1 - Hot-water supply system - Google Patents

Abstract

When the tank heat quantity does not reach the heat quantity (required heat quantity) required for executing the freeze prevention operation by the estimated hot water supply start scheduled time of the next day at the time point when the scheduled hot water supply end time of the day is reached YES), the heat storage operation is performed by operating the heat pump and the circulation pump until the required heat amount is accumulated in the tank (S50). By this heat accumulation operation, the amount of heat (hot water) required to perform the antifreezing operation is saved in the tank until the scheduled start time of hot water supply for the next day. The controller then performs the freeze prevention operation by circulating the hot water in the tank without operating the heat pump until the scheduled hot water starting time of the next day (S54 to S60).

Description

Hot-Water Supply System {HOT-WATER SUPPLY SYSTEM}

The technique disclosed herein relates to a hot water system.

Japanese Patent Application Laid-Open No. Hei 11-63661 (hereinafter referred to as Patent Document 1) discloses a storage tank for storing water, a circulation circuit (circulation circuit) for circulating water in the storage tank, A water temperature sensor for detecting the temperature of water in the storage tank; and a determination unit for determining whether or not the temperature detected by the water temperature sensor is lower than a predetermined temperature, (Heat pump hot water supply machine) having a heat pump (hot water heat exchanger) In this heat pump water heater, when it is determined that the temperature detected by the water temperature sensor is lower than the predetermined temperature, the heat pump is operated and the water in the circulation circuit is circulated to prevent the water in the circulation circuit from freezing (Anti-freezing operation).

In the technique of Patent Document 1, the start and stop of the heat pump are performed whenever the freeze prevention operation is required. As a result , the number of starting and stopping of the heat pump is increased, and the overall efficiency of the heat pump is lowered. In this specification, an increase in the number of times of starting and stopping the heat pump can be suppressed, and a hot water system capable of appropriately preventing freezing of piping flow is provided.

As a result of intensive studies by the present inventors, it has been found that, when the life cycle of various households is viewed in units of 24 hours (one day), after the last hot water is supplied in any household, Is less likely to be needed.

The hot water supply system disclosed in this specification is created based on the above knowledge. The hot water supply system disclosed in this specification includes a tank for storing water to be supplied to a hot water use place, a tank water circulation path for returning water to the tank by flowing water into the tank, An outside air temperature sensor for measuring the outside air temperature, a water temperature sensor for measuring the temperature of water in each part in the tank, and a controller. The controller determines whether or not the scheduled hot water supply end scheduled time for ending the supply of the last hot water as the time after the hot water supply start scheduled time for starting the supply of the first hot water and the time after the hot water supply start scheduled time Specify. Also, the amount of heat accumulated in the tank is calculated based on the temperature of the water in each part in the tank. When the outside air temperature is lower than the predetermined temperature after the hot water finishing end scheduled time in the present unit period, the freezing prevention operation for circulating the water in the tank water circulation path without activating the heat pump is executed, The heat storage operation for preventing freezing is performed until the amount of heat required for executing the freezing prevention operation until the hot water supply start scheduled time in the next unit period is accumulated in the tank after the hot water finishing end scheduled time in the unit period do.

The hot water supply system is provided with a heat pump for heating the hot water until the amount of heat required for executing the freezing prevention operation until the hot water supply start scheduled time in the next unit period is accumulated in the tank, To prevent the freeze-prevention operation. By the freezing prevention heat storage operation, the amount of heat (hot water) required to perform the freeze prevention operation is stored in the tank until the hot water supply start scheduled time in the next unit period. Therefore, it is possible to perform the freezing prevention operation by circulating the hot water in the tank without operating the heat pump between the scheduled hot water supply end time in the current unit period and the hot water supply start scheduled time in the next unit time have. As a result, it is possible to suppress starting and stopping the heat pump frequently. Therefore, the above-described hot water supply system can suppress an increase in the number of times of starting and stopping the heat pump, and can prevent freezing of piping flow properly.

1 is a diagram schematically showing a configuration of a hot water supply system 2 of the first embodiment.
2 is a flowchart of a first freezing prevention process executed in the hot water supply system 2 of the first embodiment from the hot water supply start scheduled time of the day to the hot water supply end scheduled time of the day.
3 is a flowchart of a second freezing prevention process executed in the hot water supply system 2 of the first embodiment from the scheduled hot water supply end time to the next hot water supply start scheduled time.
4 is a table showing a specific example (1A) of the case where the second freeze prevention treatment of the first embodiment is performed.
5 is a table showing a specific example (1B) in the case of performing the second freeze prevention treatment of the first embodiment.
6 is a flowchart of a second freezing prevention process executed between the hot water supply end scheduled time of the day and the hot water supply start scheduled time of the next day in the hot water supply system 2 of the second embodiment.
7 is a table showing a concrete example (2) in the case of performing the second freeze prevention treatment of the second embodiment.
8 is a table showing a concrete example (3) in the case of performing the second freeze prevention treatment of the third embodiment.

The main features of the embodiments described below are listed below. In addition, the technical elements described below are independent technical elements and exert their technical merit either individually or in various combinations, and are not limited to the combination of claims described in the application.

(Feature 1) The controller controls the freeze storage heat storage operation (freeze storage heat storage operation) immediately after the hot water supply completion scheduled time (hot water supply completion estimated time) in the current unit period (single period) elapses May be executed. According to this configuration, the hot water supply system is frozen until the hot water supply start scheduled time (hot water supply start time) in the next unit period immediately after the scheduled hot water supply end time in the current unit period elapses The amount of heat (hot water) required to carry out the prevention operation (anti-freeze operation) can be saved in the tank.

(Feature 2) The controller may perform the heat storage operation for preventing freezing when the amount of heat in the tank can not reach the minimum required amount of heat to perform the freeze prevention operation. According to this configuration, even if the hot water in the tank is used for hot water supply after the hot water finishing end scheduled time in the current unit period and, as a result, the amount of heat in the tank is insufficient, for example, ) To perform freezing prevention heat storage operation. Therefore, the hot water supply system can secure the amount of heat necessary for executing the freeze prevention operation up to the hot water supply start scheduled time in the next unit period irrespective of the use condition of the hot water in the tank.

(Embodiment 1)

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 inflow path 30 (tap water inflow path) A supply pump 40, a heat pump 50, a burner heating device 60, and a controller 100. The controller 100 includes a controller (not shown)

The heat pump 50 is a heat source that heats heat in the tank water circulation path 20 by absorbing heat from the outside air. The heat pump 50 includes a heat medium circulation path for circulating a heat medium (alternate freon, for example, R410A or the like) (not shown), an evaporator for performing heat exchange between the outside air and the heat medium, A heat exchanger (heat exchanger) for exchanging heat between the water in the tank water circulation passage 20 and the heat medium of high temperature and high pressure, and a heat exchanger (heat exchanger) And an expansion valve for changing the temperature to a low temperature and a low pressure. The heat pump 50 is also provided with an outside air temperature sensor 52 for measuring the outside air temperature.

The tank (10) stores hot water heated by the heat pump (50). The tank 10 is of a closed type and is covered on the outside by a heat insulating material. In the tank 10, water is stored up to full water. In this embodiment, the capacity of the tank 10 is 100L. Thermistors 11, 12, 13, 14, 15 are attached to the tank 10 at predetermined intervals in the height direction of the tank 10. Each of the thermistors 11, 12, 13, 14, and 15 measures the temperature of water at the attachment position. For example, each of the thermistors 11, 12, 13, 14, and 15 measures the temperature of water at the positions 0L, 20L, 40L, 60L, and 80L from the top of the tank 10, respectively.

An upstream end of the tank water circuit 20 is connected to the lower portion of the tank 10 and a downstream end of the tank water circulation path 20 is connected to the upper portion of the tank 10. A circulation pump (22) is inserted into the tank water circulation path (20). The circulation pump 22 sends water in the tank water circuit 20 from the upstream side to the downstream side. The tank water circuit 20 passes through a heat exchanger (not shown in the figure) of the heat pump 50. Therefore, when the heat pump 50 is operated, the water in the tank water circuit 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 circuit 20 is a water channel for storing heat in the tank 10. Further, a thermistor 24 is inserted into the tank water circulation passage 20 on the upstream side of the heat pump 50. The thermistor 24 measures the temperature of water before it passes through the heat pump 50, which is led out from the lower portion of the tank 10. In other words, the thermistor 24 measures the temperature of water at a position of 100 L from the top of the tank 10.

The tap water inflow path (30) has an upstream end connected to the tap water supply source (31). A thermistor (32) is inserted into the tap water inflow path (30). The thermistor 32 measures the temperature of tap water. The downstream side of the tap water inflow path 30 is branched into the first inflow path 30a and the second inflow path 30b. The downstream end of the first inflow passage 30a is connected to the lower portion of the tank 10. The downstream end of the second inflow passage 30b is connected in the middle of the supply passage 40 to be described later. A mixing valve (42) is provided at a connecting portion between the downstream end of the second inflow passage (30b) and the supply passage (40). The mixing valve 42 adjusts the amount by which the water in the second inflow path 30b is mixed with the hot water flowing in the supply path 40. [

The supply passage 40 has an upstream end connected to the upper portion of the tank 10. As described above, the second inflow path 30b of the tap water inflow path 30 is connected to the middle of the supply path 40, and the mixing valve 42 is provided at the connection portion. A burner heating device 60 is inserted into the supply passage 40 on the downstream side of the connecting portion with the second inflow passage 30b. Further, the thermistor 44 is inserted into the supply path 40 on the downstream side of the burner heating device 60. [ The thermistor 44 measures the temperature of the supplied hot water. When the temperature of the hot water supplied from the tank 10 to the supply path 40 (i.e., the temperature measured by the thermistor 44) does not reach the hot water setting temperature, the burner heating device 60 causes the thermistor 44 The water in the supply path 40 is heated so that the temperature of the hot water to be measured coincides with the hot water setting temperature. The downstream end of the supply path 40 is connected to a hot water utilization place (e.g., kitchen, bathtub, etc.).

The controller 100 is electrically connected to each component and controls the operation of each component.

Next, the operation of the hot water supply system 2 of the present embodiment will be described. The hot water supply system 2 can perform three operations, that is, heat storage operation, hot water supply operation (hot water supply operation) and freeze prevention operation. Each operation will be described below.

(Heat storage operation)

The heat storage operation is an operation for heating the water in the tank 10 by the heat generated by the heat pump 50. When the execution of the heat accumulation operation is instructed by the controller 100, the heat pump 50 operates and the circulation pump 22 rotates. When the circulation pump 22 rotates, the water in the tank 10 circulates in the tank water circulation passage 20. That is, water present in the lower portion of the tank 10 flows into the tank water circulation passage 20 and heated by the heat of the heating medium when the inflow water passes through the heat exchanger in the heat pump 50, 10). Accordingly, high-temperature water can be stored in the tank (10). A layer of hot water is formed on the top of the tank 10 and a layer of low temperature water is formed on the bottom.

(Hot water operation)

The hot water supply operation is an operation of supplying the water in the tank 10 to the hot water utilization site. The hot water supply operation can be executed even during the above-mentioned heat storage operation. When the hot water tap at the hot water use place is opened, the controller 100 causes tap water to flow from the tap water inflow path 30 (first inflow path 30a) to the lower portion of the tank 10 by the water pressure from the tap water supply source 31 . At the same time, the hot water in the upper part of the tank 10 is supplied to the hot water utilization place through the supply path 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 44) is higher than the hot water setting temperature, the mixing valve 42 is opened, And the tap water flows into the supply path 40 from the line 30b. Therefore, the water supplied from the tank 10 and the tap water supplied from the second inflow path 30b are mixed in the supply path 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 use place coincides with the hot water setting temperature. On the other hand, the controller 100 operates the burner heating device 60 when the temperature of the water supplied from the tank 10 to the supply path 40 is lower than the hot water setting temperature. Thus, the water passing through the supply path 40 is heated by the burner heating device 60. The controller 100 controls the output of the burner heating device 60 so that the temperature of the water supplied to the hot water use place coincides with the hot water setting temperature.

In the present embodiment, the controller 100 does not supply the water in the tank 10 to the supply path 40 when the hot water tap in the hot water use place is opened, according to the time zone, The opening of the mixing valve 42 may be adjusted so as to supply only the tap water supplied from the second inflow passage 30b to the supply passage 40. [ In this case, the controller 100 operates the burner heating device 60 to control the output so that the temperature of the water supplied to the hot water use place coincides with the hot water setting temperature.

(Freezing prevention operation)

The freeze prevention operation is an operation for preventing the water in the tank water circuit (20) (particularly, the portion of the heat pump (50) passing through the heat exchanger) from being damaged by freezing the water in the tank water circuit (20). When the execution of the freeze prevention operation is instructed by the controller 100, the circulation pump 22 is operated to circulate the water in the tank 10 in the tank water circulation path 20. As described later, in the present embodiment, the controller 100 performs the freeze prevention operation while operating the heat pump 50 together with the circulation pump 22 in a predetermined case (S22 in FIG. 2). In the present embodiment, the content of the freeze prevention processing executed by the controller 100 differs according to the time zone (see FIGS. 2 and 3), and the content of the freeze prevention operation differs accordingly.

(The processing that the controller 100 performs every 24 hours)

In this embodiment, the controller 100 performs the following processing in accordance with the daily life cycle of a household (hereinafter referred to as a " specific household ") in which the hot water supply system 2 is installed . In the present embodiment, the controller 100 sets the 24-hour period starting from 2:00 as a unit period for specifying one day.

Describe an example of a life cycle of a certain generation. In some generations, the first hot water supply occurs at about 7:00. The first hot water supply is, for example, hot water for preparing breakfast and washing. Also, around 11:30, a second hot water supply is provided for the preparation of lunch. In addition, around 19:00, hot water operation for filling hot water in the bathtub is performed. At around 22:00, the last hot water supply of the day is done. The last hot water supply is, for example, hot water for gargling.

In the present embodiment, the controller 100 stores the time at which the hot water supply has been started and the time at which the hot water supply has ended, every time hot water is supplied in a specific household. The controller 100 stores the time information of the past seven days of the specific generation. In addition, the controller 100 erases the time information eight days ago every 24 hours and newly stores the time information of the previous day.

Next, the controller 100 specifies the earliest time from the time at which the first hot water supply started in the past seven days from the time information of the past seven days of the specific generation. In certain households, it is highly likely that the first hot water supply will start after this time has elapsed. Hereinafter, this time is referred to as " hot water supply start scheduled time ".

Further, the controller 100 specifies the slowest time from the last hot water supply end time in the past seven days from the seven-day time information of the specific generation. There is a high possibility that the hot water supply will not be made until the scheduled start time of hot water supply for the next day after the elapse of this time in a certain household. Hereinafter, this time is referred to as " hot water supply end scheduled time ".

(Freeze prevention processing executed by the controller 100)

Next, the freeze prevention processing executed by the controller 100 of the hot water supply system 2 of the present embodiment will be described. As described above, in the present embodiment, the content of the freeze prevention processing executed by the controller 100 in accordance with the time zone is different (see Figs. 2 and 3). Hereinafter, two different freeze prevention treatments will be described.

(First freeze prevention treatment)

Fig. 2 is a flowchart of the first freeze prevention process executed by the controller 100. Fig. The first freezing prevention process is executed from the hot water supply start scheduled time on the day to the hot water supply end scheduled time on the day. Therefore, the controller 100 starts the first freeze prevention process when the current time passes the hot water supply start scheduled time.

The controller 100 determines that the temperature detected by the thermistor 24 is lower than 10 DEG C and the temperature detected by the ambient temperature sensor 52 is lower than 3 DEG C It is judged whether it is low or not. When the detected temperature of the thermistor 24 is lower than 10 占 폚 and the detected temperature of the outdoor air temperature sensor 52 is lower than 3 占 폚, the controller 100 determines YES in S10 and S12 and proceeds to S14.

In S14, the controller 100 operates the circulation pump 22. Thus, water in the tank 10 circulates in the tank water circulation passage 20. As a result, the temperature of the water in the tank 10 and in the tank water circuit 20 becomes uniform. The controller 100 proceeds to S16, S18, and S20 when the circulation pump 22 is operated in S14.

In S16, the controller 100 monitors that the detection temperature of the thermistor 24 is higher than 13 deg. C for three minutes. At the same time, in S18, the controller 100 monitors that the detected temperature of the outside air temperature sensor 52 becomes higher than 6 deg. At the same time, at the same time, the controller 100 monitors that the detection temperature of the thermistor 24 is lower than 8 캜 for 30 minutes.

By operating the circulation pump 22 in S14, the temperature of water in the tank 10 and in the tank water circuit 20 becomes uniform. As a result, the temperature of the water in the tank 10 and the tank water circuit 20 may become higher than 13 占 폚. If the state continues for a certain period of time (3 minutes or more), there is little possibility that the tank water circuit 20 is frozen and damaged. In this case, the controller 100 determines YES in S16 and stops the circulation pump 22 in S28. In this case, the controller 100 returns to the monitoring of S10 and S12 again.

During the operation of the circulation pump 22, the outside air temperature may become higher than 6 占 폚. In this case, there is little possibility that the tank water circuit 20 is frozen and broken. In this case, the controller 100 determines YES in S18 and stops the circulation pump 22 in S28. In this case also, the controller 100 returns to the monitoring of S10 and S12 again.

The detection temperature of the thermistor 24 may be lower than 8 占 폚 even when the circulation pump 22 is operated in S14 to circulate the water in the tank 10 and the tank water circuit 20. If the state continues for a certain period (not less than 30 minutes), the tank water circuit 20 may freeze and be damaged. In this case, the controller 100 determines YES in S20 and proceeds to S22.

In S22, the controller 100 operates the heat pump 50 again. The water passing through the tank water circuit 20 is heated by the heat pump 50 and the heated water is returned to the upper portion of the tank 10. [ As a result, the temperature of the water circulating in the tank 10 and the tank water circulation passage 20 is increased. When the heat pump 50 is operated in S22, the controller 100 proceeds to S24.

In S24, the controller 100 monitors that the detection temperature of the thermistor 24 is higher than 15 deg. C for 5 minutes. As described above, the circulation pump 22 and the heat pump 50 operate to raise the temperature of the water circulating in the tank 10 and the tank water circuit 20. When the detected temperature of the thermistor 24 rises to a temperature higher than 15 deg. C and the state continues for a certain period (5 minutes or more), there is less fear that the tank water circuit 20 is frozen and broken. In that case, the controller 100 determines YES in S24 and stops the heat pump 50 and the circulation pump 22 in S26. Upon completion of S26, the controller 100 returns to the monitoring of S10 and S12 again.

The controller 100 repeats the above-described processes of S10 to S28 within the period from the hot water supply start scheduled time to the hot water supply end scheduled time of the day.

(Second freeze prevention treatment)

3 is a flowchart of a second freeze prevention process executed by the controller 100. Fig. The second freeze prevention process is executed between the scheduled hot water supply end time of the day and the hot water supply start scheduled time of the next day (i.e., the time when the possibility of the hot water supply operation is low). The controller 100 starts the second freezing prevention process when the current time passes the hot water supply end scheduled time.

In S40 and S42, the controller 100 determines whether or not the temperature detected by the thermistor 24 is lower than 3 deg. C and the temperature detected by the ambient temperature sensor 52 is also lower than 3 deg. When the detected temperature of the thermistor 24 is lower than 3 DEG C and the detected temperature of the outdoor air temperature sensor 52 is lower than 3 DEG C, the controller 100 determines YES in S40 and S42 and proceeds to S44.

In S44, the controller 100 calculates the amount of heat accumulated in the tank 10 (hereinafter referred to as " amount of stored heat in the tank ") based on the detected temperatures of the thermistors 11 to 15 and 24. More specifically, the controller 100 calculates the tank heat quantity by the following equation (1).

(Detected temperature of the thermistor 11 + temperature detected by the thermistor 12) / 2 x 20 [L] + (detected temperature of the thermistor 12 + temperature of the thermistor 12) (The detection temperature of the thermistor 14 + the detection temperature of the thermistor 14) / 2 x 20 [L] + (the detection temperature of the thermistor 14) L) + 300 (Kcal) / 2 x 20 [L] + (Thermistor 15 + Thermistor 24) / 2 x 20 [L]

300 [Kcal] in the above equation 1 represents the minimum amount of heat of the tank 10 (minimum amount of heat storage). (3 占 폚 占 100 L) when the temperatures of the thermistors 11 to 15 and 24 are all 3 占 폚. In Expression (1), the tank axial heat quantity which is a substantial axial heat quantity in the tank (10) is calculated by subtracting this minimum axial heat quantity of 300 [Kcal] from the total axial heat quantity of the tank (10).

Subsequently, at S46, the controller 100 calculates the amount of heat (hereinafter referred to as " required heat amount (required heat amount) ") necessary for executing the freeze prevention operation continuously from the scheduled hot water supply end time point of the day to the next hot water supply start scheduled time Quot;). Specifically, in S46, the controller 100 determines whether or not the amount of heat radiation (that is, the heat radiation amount per hour) every time one predetermined freeze prevention operation is performed and the time from the scheduled hot water supply end scheduled time to the next hot water supply start scheduled time The necessary heat quantity can be calculated.

Further, at the time point S46 (the time point of the hot water supply end scheduled time of the day), since one day has not elapsed (that is, the time (2:00) at which the unit period is switched has not elapsed) Scheduled time " is not calculated. In the present embodiment, the "next day's hot water supply start scheduled time" based on the controller 100 at S46 indicates the same time as the "hot water supply start scheduled time (end of the current day)" on the next day. In the following description, " scheduled hot water starting time of next day " refers to the same time.

Subsequently, in S48, the controller 100 determines whether or not the tank heat quantity calculated in S44 is smaller than the heat quantity calculated in S46. When the tank heat quantity is smaller than the required heat quantity, the controller 100 determines YES in S48 and proceeds to S50. On the other hand, if the tank heat quantity is equal to or more than the required heat quantity, the controller 100 determines NO in S48 and skips the processing of S50 to S54 and proceeds to S58.

In S50, the controller 100 starts the heat storage operation by operating the heat pump 50 and the circulation pump 22. The hot water heated by the heat pump 50 is stored in the tank 10. When the heat accumulation operation is started in S50, the controller 100 proceeds to S52.

In S52, the controller 100 monitors that the tank heat quantity becomes equal to or higher than the required heat quantity. As described above, the high temperature water is stored in the tank 10 by starting the heat storage operation in S50. Accordingly, when the detection temperatures of the thermistors 11 to 15 and 24 rise, the tank heat quantity increases. As a result, when the tank heat quantity becomes equal to or higher than the required heat quantity, the controller 100 determines YES in S52 and proceeds to S54. In S52, the controller 100 calculates the tank heat quantity at predetermined time intervals.

In S54, the controller 100 stops the heat pump 50 to terminate the heat storage operation. At S54, the controller 100 continues to operate the circulation pump 22. That is, in S54, the controller 100 terminates the heat storage operation and starts the freeze prevention operation. When the circulation pump 22 is operated in S54, water is circulated in the tank 10 and in the tank water circuit 20. As described above, the amount of heat exceeding the required heat amount is stored in the tank 10. Therefore, in the tank 10 and the tank water circulation passage 20, water at a temperature sufficient to prevent freezing damage of the tank water circuit 20 is circulated. As a result, freezing breakage of the tank water circuit (20) is prevented.

In S58, the controller 100 activates the circulation pump 22 to perform the freeze prevention operation. If the circulation pump 22 does not operate at the time of S58 as in the case of NO at S48, the controller 100 starts the freeze prevention operation by operating the circulation pump 22 at S58. On the other hand, when the circulation pump 22 is already operating at the time of S58 and the freezing prevention operation is being performed, the controller 100 continuously operates the circulation pump 22 in S58. After finishing S58, proceed to S60.

Subsequently, in S60, the controller 100 monitors that the current time reaches the hot water supply start scheduled time (" hot water starting scheduled time of next day " In other words, the controller 100 continues to operate the circulation pump 22 until the hot water supply start scheduled time and continues the freeze prevention operation. When the current time passes the scheduled hot water supply start time, the controller 100 determines YES in S60 and ends the second freeze prevention processing (Fig. 3). In this case, the controller 100 stops the circulation pump 22.

In the present embodiment, the controller 100 controls the water in the tank 10 to flow into the supply path 40 when the hot water stopper of the hot water use place is opened during the execution of the second freeze prevention processing And the opening of the mixing valve 42 is adjusted so as to supply only the tap water supplied from the second inflow passage 30b to the supply passage 40. [ In this case, the controller 100 operates the burner heating device 60 to control the output so that the temperature of the water supplied to the hot water use place coincides with the hot water setting temperature. Therefore, in the present embodiment, even when the hot water supply operation is performed during the execution of the second freeze prevention treatment, the hot water in the tank 10 is not supplied to the hot water utilization site, so that the tank heat amount is not reduced by the hot water supply. For this reason, in the present embodiment, there is no situation in which the freezing prevention operation can not be performed due to the shortage of the tank heat quantity during the execution of the second freeze prevention treatment.

Next, with reference to Fig. 4 and Fig. 5, a specific example of the case where the second freezing prevention process is executed in the hot water supply system 2 of the present embodiment will be described. In the examples of Figs. 4 and 5, the scheduled hot water supply end time is 22:00 on the day and the hot water supply start scheduled time on the next day is 7:00. The time from the scheduled hot water ending time of the day to the hot water starting scheduled time of the next day is nine hours. The amount of heat released from the tank 10 and the tank water circuit 20 every hour is 200 Kcal.

(Specific example (1A): Fig. 4)

A specific example (1A) will be described with reference to Fig. When the current time reaches 22:00, which is the scheduled hot water supply end time, the controller 100 starts the second freeze prevention processing (see FIG. 3). In this example, the tank heat amount calculated at 22:00 is 4200 Kcal, and the required heat amount is 1800 Kcal. The calculation method of the tank heat quantity and the heat quantity required is as described above. Therefore, in the example of FIG. 4, the amount of heat to accumulate the required heat amount is accumulated in the tank 10 at 22:00. Therefore, in this example, the controller 100 does not perform heat storage operation at 22:00 (NO in S48 of FIG. 3). In this example, the controller 100 then operates the circulation pump 22 to perform the freeze prevention operation until 7:00, which is the scheduled hot water supply end time of the next day. During the freeze prevention operation, the heat pump 50 does not operate. As a result, at 7:00, the tank heat capacity decreases to 2400 Kcal.

(Specific example (1B): Fig. 5)

A specific example (1B) will be described with reference to Fig. In this example, the tank heat quantity calculated at 22:00 is 1400 Kcal, which is smaller than the required heat quantity (1800 Kcal). In other words, in the example of FIG. 5, the amount of heat to supply the required heat amount is not accumulated in the tank 10 at 22:00. Therefore, in this example, the controller 100 performs the heat storage operation at 22:00 (YES in S48 of FIG. 3, S50). As a result of the heat storage operation up to 22:05, the tank heat quantity increases to 2200 Kcal, and the required heat quantity is increased (YES in S52 of FIG. 3). Therefore, the controller 100 stops the heat storage operation (S54 in Fig. 3). In this example as well, the controller 100 then operates the circulation pump 22 until the scheduled hot water supply end time of the next day is 7:00 to circulate the water in the tank 10 and in the tank water circuit 20, . As a result, the tank heat capacity decreases to 400 Kcal at 7:00.

The configuration and operation of the hot water supply system 2 of the present embodiment have been described above. As described above, in the hot water supply system 2 of the present embodiment, when the tank heat quantity can not reach the required heat quantity at the time point of the scheduled hot water supply end time of the day, as shown in S48 to S52 in Fig. 3, The heat pump 50 and the circulation pump 22 are operated to accumulate in the tank 10 to perform the heat accumulation operation. By this heat accumulation operation, the amount of heat (hot water) necessary for executing the freeze prevention operation is stored in the tank 10 by the scheduled hot water supply start time of the next day. Therefore, in the hot water supply system 2 of the present embodiment, it is possible to perform the freeze prevention operation by circulating the hot water in the tank without operating the heat pump until the next hot water starting scheduled time of the next day. As a result, it is possible to suppress starting and stopping the heat pump 50 frequently from the scheduled hot water supply end time of the day to the scheduled hot water supply start scheduled time of the next day. Therefore, the hot water supply system 2 of the present embodiment can suppress the increase in the number of times of starting and stopping the heat pump 50, and can prevent the freezing of the tank water circuit 20 as appropriate.

The correspondence relationship described in this embodiment and the claims will be described. The thermistors 11 to 15 and 24 are examples of a " water temperature sensor ". The scheduled hot water supply end time of the day and the hot water supply start scheduled time of the next day are each an example of the "hot water supply end scheduled time in the current unit period" and "hot water supply start scheduled time in the next unit period", respectively. The heat storage operation executed in S50 of Fig. 3 is an example of " freezing prevention heat storage operation ".

(Second Embodiment)

Next, the hot water supply system 2 of the second embodiment will be described with reference to FIGS. 6 and 7, focusing on differences from the first embodiment. The basic structure of the hot water supply system 2 of the present embodiment is also common to that of the first embodiment. However, in the present embodiment, the content of the second freeze prevention processing executed by the controller 100 is different from that of the first embodiment. In the second freeze prevention treatment in this embodiment, when the tank heat quantity becomes lower than a predetermined threshold (critical value) which is the minimum necessary value for execution of the freeze prevention operation after the elapse of the scheduled hot water supply end time of the day The second embodiment differs from the first embodiment in that the heat storage operation is performed as much as necessary.

6 is a flowchart of the second freeze prevention process of the present embodiment. In this embodiment as well, the controller 100 starts the second freezing prevention process when the current time passes the scheduled hot water supply end time. S70 and S72 are the same as S40 and S42 in Fig. In S74, the controller 100 calculates the tank heat quantity. The calculation method of the tank heat quantity is given by the above-mentioned equation (1).

Subsequently, in S76, the controller 100 determines whether or not the tank heat quantity is smaller than a predetermined threshold value Q. Here, in the present embodiment, the predetermined threshold value Q is set to a value (for example, 200 Kcal) of the amount of heat radiation (amount of heat radiation per hour) for each one hour of the predetermined freeze prevention operation. That is, the amount of heat required for freeze prevention operation for at least one hour is not accumulated in the tank 10 when the amount of stored heat in the tank is lower than the threshold value Q. In this case, the controller 100 determines YES in S76 and proceeds to S78. On the other hand, if the value of the tank heat quantity is equal to or higher than the predetermined threshold value Q, the controller 100 determines NO in S76 and skips the processing of S78 to S84 and proceeds to S88.

At S78, the controller 100 calculates the required heat quantity between the scheduled hot water supply end time of the day and the scheduled hot water supply start scheduled time of the next day. Then, in S80, the controller 100 starts the heat accumulation operation by operating the heat pump 50 and the circulation pump 22. The hot water heated by the heat pump 50 is stored in the tank 10. When the heat accumulation operation is started in S80, the controller 100 proceeds to S82.

In S82, the controller 100 monitors that the tank heat quantity becomes equal to or higher than the required heat quantity. As described above, by starting the heat accumulation operation in S80, high temperature water is stored in the tank 10, and the amount of heat of the tank increases. As a result, if the tank heat quantity becomes equal to or higher than the required heat quantity, the controller 100 determines YES in S82 and proceeds to S84. Further, in S82, the controller 100 calculates the tank heat quantity at predetermined time intervals.

In S84, the controller 100 stops the heat pump 50 to terminate the heat storage operation. In S84, the controller 100 continues to operate the circulation pump 22. That is, in S84, the controller 100 terminates the heat accumulation operation and starts the freeze prevention operation.

In S88, the controller 100 operates the circulation pump 22 to perform the freeze prevention operation. If the circulation pump 22 is not operating at the time of S88 as in the case of NO at S76, the controller 100 starts the freeze prevention operation by operating the circulation pump 22 at S88. On the other hand, when the circulation pump 22 is already operating at the time of S88 and the freezing prevention operation is being performed, the controller 100 continuously operates the circulation pump 22 in S88. When S88 is finished, proceed to S90.

Then, at S90, it is determined whether or not the current time has reached the hot water supply start scheduled time (scheduled hot water supply start scheduled time of the next day). If the current time is earlier than the hot water supply start scheduled time, the controller 100 determines NO in S90 and returns to S74 to repeat the processes of S74 to S90.

When the processes of S74 to S90 are repeatedly executed, the time when the controller 100 judges YES in the second and subsequent steps S76 to execute the process of S78 is later than the estimated time of the hot water supply end. Therefore, in S78 in this case, the controller 100 calculates the amount of heat required to continue the freeze prevention operation from the time point of S78 to the next scheduled hot water starting time, as the required heat amount. Specifically, the controller 100 can calculate the required heat amount by multiplying the predetermined heat radiation amount for one hour by the time from the time point S78 to the next hot water starting time. Similarly, in S82, the controller 100 monitors whether or not the tank heat quantity becomes equal to or more than the required heat quantity calculated in S78.

On the other hand, when the current time passes the hot water supply start scheduled time, the controller 100 determines YES in S90 and ends the second freeze prevention processing (Fig. 6). In this case, the controller 100 stops the circulation pump 22.

Also in this embodiment, when the hot water stopper of the hot water use place is opened during the execution of the second freeze prevention processing (when there is a hot water supply request), the controller 100 controls the water in the tank 10 The opening of the mixing valve 42 is adjusted so that only the tap water supplied from the second inflow passage 30b is supplied to the supply passage 40 without being supplied to the supply passage 40. [ In this case, the controller 100 operates the burner heating device 60 and controls the output of the burner heating device 60 so that the temperature of the water supplied to the hot water use place coincides with the hot water setting temperature.

(Specific example (2): Fig. 7)

Next, with reference to Fig. 7, a specific example of the case where the second freeze prevention processing is executed in the hot water supply system 2 of the present embodiment will be described. 7, the respective conditions such as the scheduled hot water supply end time (22:00) of the day, the hot water supply start scheduled time (7:00) of the next day, the heat radiation amount (200Kcal) per hour, same.

In this example, the calorific value of the tank calculated at 22:00 is 400 Kcal, which is less than the required calorie (1800 Kcal). However, the tank heat quantity at the time of 22:00 is larger than the threshold value (Q) (200 Kcal) (NO in S76 of Fig. 6). In this example, the threshold value Q is set to a value (200 Kcal) of heat radiation amount per hour. Therefore, the controller 100 does not perform the heat accumulation operation at this time but operates the circulation pump 22 to circulate the water in the tank 10 and the tank water circuit 20 to perform the freeze prevention operation Of S88).

After that, the amount of stored heat of the tank calculated at the time of 0:00 is 0, which is smaller than the threshold value Q (YES in S76 of Fig. 6). That is, at the time point of 0:00, the minimum amount of heat accumulated for one hour in the freezing prevention operation is not accumulated in the tank 10. Therefore, the controller 100 calculates the amount of heat required for executing the freeze prevention operation from the time point of 0:00 to the scheduled hot water starting time (7:00) of the next day as the required heat amount (S78 in FIG. 6). In this case, the required calorie is 1400 Kcal (200 Kcal x 7). Subsequently, the controller 100 performs heat storage operation (S80 in Fig. 6). As a result of the heat storage operation up to 0:30, the tank heat quantity increases to 1300 Kcal and becomes equal to the required heat quantity (YES in S82 of FIG. 6). In this case, the controller 100 stops the heat pump 50 to terminate the heat accumulation operation, and continues to operate the circulation pump 22 to start the freeze prevention operation (S84 in FIG. 6).

Thereafter, the controller 100 continues to operate the circulation pump 22 until 7:00, which is the scheduled hot water supply end time of the next day, to circulate water in the tank 10 and the tank water circuit 20 to prevent freezing do. As a result, at the time of 7:00, the tank heat quantity is reduced to exactly zero.

The configuration and operation of the hot water supply system 2 of the present embodiment have been described above. As described above, in the hot water supply system 2 of the present embodiment, as shown in S76 to S82 in Fig. 6, after the elapse of the scheduled hot water supply end time of the day, the tank heat quantity is adjusted to the threshold value Q The heat storage operation is performed until the required heat quantity is accumulated in the tank 10. [ By this heat accumulation operation, the amount of heat (hot water) necessary for executing the freeze prevention operation is stored in the tank 10 by the scheduled hot water supply start time of the next day. Therefore, also in the hot water supply system 2 of the present embodiment, the freezing prevention operation can be performed by circulating the hot water in the tank without operating the heat pump 50 until the next hot water supply start scheduled time of the next day. That is, in this embodiment as well, it is possible to suppress starting and stopping the heat pump 50 frequently, and also to prevent freezing of the tank water circuit 20 properly.

The correspondence relationship described in this embodiment and the claims will be described. The heat storage operation executed in S80 of Fig. 6 is an example of the " freezing prevention heat storage operation ". Further, the calorific value of the threshold value Q is an example of " predetermined calories ".

(Third Embodiment)

Next, the hot water supply system 2 of the third embodiment will be described with reference to Fig. 8, focusing on differences from the second embodiment. In the hot water supply system 2 of the present embodiment, the controller 100 executes the same second freeze prevention operation (Fig. 6) as in the second embodiment. However, in the present embodiment, the controller 100 controls the water in the tank 10 to be supplied to the supply path 40 (when there is a hot water supply request) when the hot water tap at the hot water use place is opened during the execution of the second freeze prevention processing The opening degree of the mixing valve 42 is adjusted. In this case, the controller 100 controls the opening of the mixing valve 42 and the output of the burner heating device 60 so that the temperature of the water supplied from the tank 10 becomes equal to the hot water setting temperature. In the present embodiment, when the hot water supply operation is performed during the execution of the second freeze prevention treatment, since the hot water in the tank 10 is supplied to the hot water use place, the amount of stored heat of the tank is reduced by hot water supply.

(Concrete example (3): Fig. 8)

Next, a specific example of the case where the second freeze prevention processing is executed in the hot water system 2 of the present embodiment will be described with reference to Fig. 8, the conditions such as the scheduled hot water supply end time (22:00) of the day, the hot water supply start scheduled time (7:00) of the next day, the heat radiation amount (200Kcal) .

In this example, the calorific value of the tank calculated at 22:00 is 4200 Kcal, which is higher than the required calorie (1800 Kcal). Naturally, the tank heat quantity is larger than the threshold value Q (200 Kcal) (NO in S76 of Fig. 6). Therefore, the controller 100 does not perform the heat accumulation operation at this time but operates the circulation pump 22 to circulate the water in the tank 10 and the tank water circuit 20 to perform the freeze prevention operation Of S88).

In this example, the hot water supply operation is performed between 2:00 and 3:00. In the present embodiment, when the hot water supply operation is performed during the execution of the second freeze prevention processing, the hot water in the tank 10 is supplied to the hot water utilization site. Therefore, as shown in FIG. 8, the amount of heat of the tank decreases greatly between 2:00 and 3:00. The tank heat quantity calculated at the time of 3:00 is 320 Kcal, which is larger than the threshold value Q (200 Kcal) (NO in S76 of FIG. 6). Therefore, the controller 100 continues to perform the freeze prevention operation (S88 in Fig. 6). In addition, the tank heat quantity calculated at the time of 3:05 increases from the heat quantity of 320Kcal at the time of 3:00 to 400Kcal. This is because the circulation pump 22 is operated, 20 are equalized.

Then, the amount of stored heat of the tank calculated at 5:00 is 0, which is smaller than the threshold value Q (YES in S76 of FIG. 6). That is, at the time point of 5:00, the tank 10 does not accumulate the minimum amount of heat for freeze prevention operation. Therefore, the controller 100 calculates the amount of heat required to perform the freeze prevention operation from the time point of 5:00 to the scheduled hot water starting time (7:00) of the next day as the required heat amount (S78). In this case, the required calorie is 400 Kcal (200 Kcal x 2). Subsequently, the controller 100 performs heat storage operation (S80 in Fig. 6). As a result of the heat storage operation up to 5:10, the tank heat quantity increased to 400 Kcal and became equal to the required heat quantity (YES in S82 of FIG. 6). In this case, the controller 100 stops the heat pump 50 to terminate the heat accumulation operation, and continues to operate the circulation pump 22 to start the freeze prevention operation (S84 in FIG. 6).

Thereafter, the controller 100 continues to operate the circulation pump 22 until 7:00, which is the scheduled hot water supply end time of the next day, to circulate water in the tank 10 and the tank water circuit 20 to prevent freezing do. As a result, at the time of 7:00, the tank heat quantity is reduced to exactly zero.

The configuration and operation of the hot water supply system 2 of the present embodiment have been described above. The hot water supply system 2 of the present embodiment also performs the heat storage operation when the tank heat quantity after the elapse of the hot water finishing scheduled time on that day does not reach the minimum required value Q for the execution of the freeze prevention operation. Therefore, the hot water supply system 2 of the present embodiment uses hot water in the tank 10 for hot water during the execution of the second freeze prevention treatment, and as a result, even if the amount of heat in the tank 10 is insufficient, The heat storage operation can be executed at a time point when the temperature is insufficient. Therefore, according to the hot water supply system 2 of the present embodiment, the required heat quantity can be ensured regardless of the use condition of the hot water in the tank 10. [

Although the embodiments have been described in detail, the present invention is not limited to these embodiments. The techniques described in the claims include various modifications and changes to the specific examples described above.

(Modified Example 1) In the third embodiment, when the scheduled hot water supply end time of the day has elapsed, from the time point when the hot water supply end scheduled time of the day has elapsed to the scheduled hot water supply start scheduled time (7:00) In the case where the amount of heat required to perform the freeze prevention operation is lower than the required amount of heat, the heat storage operation may be performed until the amount of heat accumulated in the tank exceeds the required heat amount.

(Variation 2) In the above embodiments, when the outside air temperature (the temperature measured by the temperature sensor 52) exceeds 6 占 폚 while the controller 100 is performing the second freezing prevention process, The controller 100 may terminate the second freeze prevention processing.

(Variation 3) The various values such as the value of the threshold value Q and the value of the minimum axial heat quantity are not limited to those exemplified in the above-mentioned embodiments, but may be arbitrary values depending on the environment and the like.

Claims (3)

As a hot water supply system,
A tank for storing water to be supplied to the hot water use place,
A tank water circulation path for introducing water in the tank and returning the introduced water to the tank,
A heat pump which absorbs heat from the outside air to heat water in the tank water circulation path,
An outside temperature sensor for measuring an outside temperature,
A water temperature sensor for measuring the temperature of water in each part in the tank,
Controller
Respectively,
The controller,
The hot water supply start time (hot water supply start time) at which the supply of the first hot water starts at the start of the hot water supply start time (Hot water finishing estimated time) at which the supply of hot water is finished,
The amount of heat accumulated in the tank is calculated based on the temperature of water in each part in the tank,
When the outside air temperature is lower than the predetermined temperature after the hot water finishing end scheduled time in the current unit period, the freezing prevention operation (freeze prevention operation) for circulating the water in the tank water circuit without operating the heat pump is executed together,
The heat pump is operated until the amount of heat required for executing the freezing prevention operation until the hot water supply start scheduled time in the next unit period is accumulated in the tank after the hot water finishing end scheduled time in the current unit period (Heat storage operation for preventing freezing)
Hot water supply system.
The method according to claim 1,
The controller executes the above-described freezing prevention heat storage operation immediately after the hot water supply end scheduled time in the current unit period elapses
Hot water supply system.
3. The method according to claim 1 or 2,
The controller executes the above-described freezing prevention heat storage operation when the amount of heat in the tank does not reach the minimum required amount of heat to perform the freeze prevention operation
Hot water supply system.

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