Hot water supply control system

Abstract

To provide a hot water supply control system capable of appropriately setting an operating period during which a water heater having a heating part that heats water using electric power supplied to a facility from a power system, can operate.SOLUTION: Provided is a hot water supply control system for controlling operation of a water heater 16 having a heating part 17 that heats water using electric power supplied to a facility 2 from a power system 1. The hot water supply control system, within a control target period composed of a plurality of unit periods, among the total predicted electric power load for each unit period predicted at the facility 2 provided with the water heater 16, identifies a predicted second electric power load per unit period that excludes a predicted first electric power load of the water heater 16, sets a time zone including the unit periods in which the predicted second electric power load exceeds a predetermined threshold as a heating operation prohibition period for the heating part 17, and sets the threshold to a value greater than the median of the predicted second electric power loads for each of the plurality of unit periods within the control target period.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a hot water supply control system that controls the operation of a hot water supply device having a heating unit that heats water using electric power supplied from an electric power system to a facility.

Background Art

[0002] In an electric power system, when many electricity consumers use electrical equipment in the same time period, the total power consumption by a plurality of electricity consumers in that time period increases. For example, during a day, in specific time periods such as in the early morning or evening, there is a tendency for the total power consumption by a plurality of electricity consumers to increase.

[0003] On days when the temperature is particularly high or particularly low, etc., the power consumption for cooling or heating purposes by electricity consumers increases, and the utilization rate of electricity in the electric power system may become very high. In that case, in order to reduce the total power consumption by electricity consumers, there may be a request for power saving for electricity consumers. In addition, a method has also been proposed to reduce the total power consumption by a plurality of electricity consumers in a specific time period by shifting the operating time period of a specific electrical equipment used by the electricity consumers in time.

[0004] For example, Patent Document 1 (Japanese Unexamined Patent Application Publication No. 2023-47383) describes a hot water supply control device that controls a plurality of hot water supply machines installed in an electricity demand area. This hot water supply machine is a storage type hot water supply machine equipped with a heat pump unit as a heating unit that heats water using electric power. And in the invention described in Patent Document 1, the power consumption consumed outside a plurality of hot water supply machines in the electricity demand area during a planned target period is predicted, and based on the predicted power consumption for each time period, a boiling prohibition period for prohibiting each of the plurality of hot water supply machines from executing a boiling operation is determined, and the time periods during which each of the plurality of hot water supply machines executes a boiling operation are planned for time periods other than the boiling prohibition period during the planned target period.

[0005] Patent Document 1 describes a boiling prohibition period during which the execution of the boiling operation is prohibited, including a first prohibition period and a second prohibition period. The first prohibition period is a predetermined period during which high power consumption is expected within a day. The second prohibition period is set for time zones where the predicted power consumption value is greater than a reference value (e.g., the average value of the predicted power consumption values for each time zone in a day) and the time zones before and after it.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] In the invention described in Patent Document 1, in order to set the second prohibition period, the average value of the predicted power consumption values for each time zone in a day is used. However, if there is a time zone where the predicted power consumption value is extremely small compared to others, that is, if the average value becomes extremely small due to the predicted value of that time zone, it is conceivable that the number of time zones where the predicted power consumption value exceeds that average value will be extremely large.

[0008] In that case, most of the time zones in a day will be set as the second prohibition period, and the time zones during which the boiling operation of the water heater can be executed will be limited to a few time zones. That is, the boiling operations of multiple water heaters will be concentrated and executed in a few time zones, resulting in the problem that the power consumption in that time zone becomes extremely large.

[0009] Alternatively, if there is a time period during which the predicted power consumption is extremely large compared to others, that is, if the average value becomes extremely large due to the predicted value during that time period, the predicted power consumption of other time periods may fall below the average value. As a result, only the time period during which the predicted power consumption is extremely large compared to others and the time periods before and after it are set as the second prohibited period. Even if there are other time periods with relatively high power consumption, those time periods may become time periods during which the execution of the boiling operation is not prohibited. And if the boiling operation is actually executed during a time period when its execution is not prohibited, there may arise a problem that the power consumption during that time period becomes extremely large.

[0010] Thus, it is not preferable to divide each time period of a day into a boiling prohibition period and other periods by using the average value of the predicted power consumption for each time period of a day as described in Patent Document 1.

[0011] The present invention has been made in view of the above problems, and an object thereof is to provide a hot water supply control system that can appropriately set a period during which a hot water supply device having a heating unit that heats water using electric power supplied from an electric power system to a facility can operate.

Means for Solving the Problems

[0012] A characteristic configuration of a hot water supply control system according to the present invention for achieving the above object is a hot water supply control system that controls the operation of a hot water supply device having a heating unit that heats water using electric power supplied from an electric power system to a facility, In a control target period composed of a plurality of unit periods, among the total predicted power loads for each unit period predicted in the facility where the hot water supply device is provided, identify the predicted second power load for each unit period that does not include the predicted first power load of the hot water supply device, Set a time period including the unit period in which the predicted second power load for each unit period is greater than a predetermined threshold as an operation prohibition period for prohibiting the heating operation of the heating unit, The threshold is set to a value greater than the median value of the predicted second power loads for each of the plurality of unit periods in the control target period.

[0013] The threshold value may be set to a value obtained by adding, to the median value, a value obtained by dividing the unit power load when the water heater provided in the facility operates throughout the unit period by a predetermined value.

[0014] The threshold value may be set to a value obtained by adding, to the median value, a value obtained by dividing the unit power load when the water heater provided in the facility operates throughout the unit period by a predetermined value and multiplying the result by the ratio of the number of the consumer sections in which the water heater is provided to the total number of the consumer sections provided in the facility.

[0015] The predetermined value may be a value in the range of 5 to 50.

[0016] According to the above characteristic configuration, among the total predicted power loads per unit period predicted in the facility where the water heater is provided, a time period including a unit period in which the predicted second power load per unit period, which does not include the predicted first power load of the water heater, is greater than a predetermined threshold value set to be greater than the median value of the predicted second power loads per unit period in a plurality of unit periods during the control target period is set as an operation prohibition period for prohibiting the heating operation of the heating unit. That is, since the water heater is not operated in a unit period in which the predicted second power load is relatively large, it is possible to avoid the total power load of the facility in such a unit period in which the predicted second power load is relatively large from further increasing due to the operation of the water heater. Therefore, even in a tariff system in which the electricity tariff increases as the power load per unit period of the facility increases, an increase in the electricity tariff can be suppressed. Further, since the above threshold value is set using the median value of the predicted second power loads per unit period in a plurality of unit periods during the control target period, more than half of the plurality of unit periods included in the control target period are not set as the operation prohibition period. That is, since a large number of unit periods in which the water heater may be operated can be set, it is expected that a plurality of water heaters will be operated in a time-dispersed manner. Therefore, it is possible to provide a hot water supply control system that can appropriately set a period during which a water heater having a heating unit that heats water using electric power supplied from an electric power system to a facility can operate.

[0017] Another characteristic configuration of the hot water supply control system according to the present invention is that the facility is provided with a plurality of consumer compartments to which the power received collectively from the power grid is distributed and supplied, and the water heater is provided in at least one of the plurality of consumer compartments.

[0018] According to the above characteristic configuration, in a facility provided with a plurality of consumer compartments that receive power collectively from the power grid, among the total predicted power loads per unit period predicted in the facility, the water heater is not operated in a unit period in which the predicted second power load per unit period, which does not include the predicted first power load of the water heater, is relatively large. Therefore, it is possible to avoid the power load in the unit period in which the predicted second power load is relatively large from becoming even larger due to the operation of the water heater.

Brief Description of the Drawings

[0019]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0020] Hereinafter, with reference to the drawings, a hot water supply control system according to an embodiment of the present invention will be described. FIG. 1 is a diagram showing the configuration of a facility in which a hot water supply control system is provided. As shown in the figure, in a facility 2 supplied with power from a power grid 1, a plurality of customer sections 10 are provided. In the facility 2, the power collectively received from the power grid 1 using the power receiving equipment 3 is supplied to each customer section 10. That is, in the facility 2, a plurality of customer sections 10 to which the power collectively received from the power grid 1 is distributed and supplied are provided. For example, the facility 2 is a building of an apartment house, and in that case, each customer section 10 is each household. Alternatively, the facility 2 is a building in which business establishments such as stores are gathered, and in that case, each customer section 10 is each business establishment. In FIG. 1, two customer sections 10A and 10B are drawn, but the number of customer sections 10 provided in the facility 2 can be set as appropriate.

[0021] Note that the facility 2 means a range realized such that power is supplied via the power receiving equipment 3, and there may be cases where a plurality of customer sections 10 are included in a single building or in separate buildings.

[0022] In the customer section 10, a water heater 16, an electric load section 18, a hot water storage tank 12, etc. are provided. The water heater 16 has a heating section 17 that heats water using the power supplied from the power grid 1 to the facility 2. The heating section 17 can be realized using a device that heats water by a heat pump unit using an electric compressor, a device that heats water using a combination of a heat pump unit using an electric compressor and a combustor that burns fuel, a device that heats water by an electric heater, etc.

[0023] In this embodiment, the water heater 16 is configured to be able to heat the hot water stored in the hot water storage tank 12 as a heat storage device. Specifically, a circulation path 15 is provided for the hot water to circulate between the hot water storage tank 12 and the water heater 16. The hot water supplied from the hot water storage tank 12 to the water heater 16 is heated by the water heater 16 and then returned to the hot water storage tank 12. Further, a water supply path 13 for supplying make-up water and a hot water discharge path 14 for discharging the stored hot water are connected to the hot water storage tank 12. A water supply pressure is applied to the hot water stored in the hot water storage tank 12 via the water supply path 13. When the hot water inside the hot water storage tank 12 is discharged through the hot water discharge path 14, make-up water is supplied from the water supply path 13 to the hot water storage tank 12 accordingly. Since heat can be stored in the hot water storage tank 12, the water heater 16 can be operated before the timing when the hot water is consumed in the consumer section 10, and the degree of freedom in the operation timing of the water heater 16 is increased.

[0024] The electric power load section 18 is a device that operates using the electric power supplied from the power system 1 to the facility 2 separately from the water heater 16, and is, for example, devices such as lighting devices and air conditioning devices provided in the consumer section 10.

[0025] In the consumer section 10, a power consumption measurement section 11 for measuring the electric power supplied to the water heater 16 and the electric power load section 18 is provided. The measurement result of the power consumption measurement section 11 is transmitted to the individual control section 19. Further, the individual control section 19 monitors and collects the heating start time when the water heater 16 starts the heating operation and the heating stop time when the heating operation ends.

[0026] In the consumer section 10, a heat consumption measurement section 20 for measuring the amount of heat discharged from the hot water storage tank 12 through the hot water discharge path 14 is provided. For example, the heat consumption measurement section 20 measures the temperature of the discharged hot water and the flow rate per unit time. The measurement result of the heat consumption measurement section 20 is transmitted to the individual control section 19.

[0027] In the user section 10, the individual control unit 19 causes a storage unit (not shown) to store past data including information on the transition of power consumption and heat consumption per unit time in the past. For example, the past data includes information on the transition of power consumption and heat consumption per unit time for, say, the past four weeks, together with attribute data such as day of the week, weekdays, and holidays. As a result, the individual control unit 19 can derive, by referring to the past data, the transition of predicted power consumption and predicted heat consumption per unit time, for example, for the next day. Then, the individual control unit 19 determines a scheduled operation period such that the operation merit of the water heater 16 (for example, the degree of reduction in primary energy consumption, the degree of reduction in energy cost, or the degree of reduction in carbon dioxide emissions, or a combination thereof) increases, on the condition that the predicted heat consumption per unit time for the next day can be covered, taking into account, for example, the primary energy consumption, energy cost, and carbon dioxide emissions of the received power from the power grid 1, and the heat dissipation amount from the hot water storage tank 12. During the scheduled operation period, a heating operation is performed to heat the hot water stored in the hot water storage tank 12. However, if an operation prohibition period during which the heating operation is prohibited is set, the individual control unit 19 sets the scheduled operation period in a period other than the operation prohibition period and performs the heating operation.

[0028] In the present embodiment, as will be described later, the control device 5 included in the hot water supply control system sets an operation prohibition period and transmits it to the individual control units 19 of the respective user sections 10.

[0029] The facility 2 is provided with a total power measurement unit 4 that measures the total power supplied to the plurality of user sections 10 via the power reception facility 3. The measurement result of the total power measurement unit 4 is transmitted to the control device 5.

[0030] The control device 5 is realized, for example, using a server or the like capable of information communication between the facility 2 and each user section 10. The control device 5 is provided with a storage unit 6 for storing the information to be handled.

[0031] The control device 5 collects information on the heating start time and heating stop time of each water heater 16 from the individual control units 19 of a plurality of customer sections 10 and stores it in the storage unit 6. Further, the storage unit 6 also stores information on the power consumption while each water heater 16 is performing a heating operation. Therefore, the control device 5 can calculate the power load of each water heater 16 (for example, the power consumption amount in a unit period, the average power consumption in a unit period, etc.) for each predetermined unit period such as every 30 minutes or every hour.

[0032] The length of the unit period can be set as appropriate. For example, in Facility 2, in a case where there is a tariff system such that the higher the maximum average power consumption among the average power consumptions of Facility 2 for each predetermined period (for example, every 30 minutes) within a past setting period (for example, one year), the higher the electricity charge. In such a case, it is preferable to reduce the average power consumption of Facility 2 for each predetermined period. In such a case, the unit period of the present embodiment can be set to the same length as that predetermined period. That is, in that case, the unit period is set to the period for calculating the power load that is the basis for calculating the electricity charge of Facility 2. For example, in a case where there is a tariff system such that the higher the power load of Facility 2 for each predetermined period within a past setting period, the higher the electricity charge of Facility 2, it is set to the same period as the above-mentioned predetermined period.

[0033] Therefore, based on the measurement result of the total power measurement unit 4 that measures the total power supplied to a plurality of customer sections 10 via the power receiving facility 3 and the calculated power load of each water heater 16 for each predetermined unit period, the control device 5 can calculate the second power load for each unit period that does not include the first power load of the water heater 16 among the total power loads for each unit period in Facility 2.

[0034] Based on the data of the past transition of the second power load for each unit period in the facility 2, the control device 5 can calculate the predicted second power load for each of the plurality of unit periods that make up the future control target period (e.g., one day, etc.) in the facility 2. That is, in the control target period composed of a plurality of unit periods, the control device 5 can identify the predicted second power load for each unit period that does not include the predicted first power load of the water heater 16 among the total predicted power loads for each unit period predicted in the facility 2 where the water heater 16 is provided. For example, the control device 5 stores information about the transition of the second power load for each unit time, such as for the past four weeks, in the storage unit 6 together with attribute data such as day of the week, weekdays, and holidays. Then, the control device 5 can calculate the transition of the predicted second power load for each unit time that makes up the future control target period by referring to the information stored in the storage unit 6.

[0035] Then, the control device 5 can set the time zone including the unit period in which the predicted second power load for each unit period is greater than a predetermined threshold as an operation prohibition period for prohibiting the heating operation of the heating unit 17. The control device 5 sets this threshold to a value greater than the median value of the predicted second power loads for each of the plurality of unit periods in the control target period.

[0036] Furthermore, the control device 5 transmits the set operation prohibition period to the individual control units 19 of each consumer section 10. As a result, the individual control unit 19 will perform the heating operation of the water heater 16 during the periods other than the operation prohibition period.

[0037] FIG. 2 is a flowchart for explaining the operation prohibition period setting process performed by the control device 5. The control device 5 executes this operation prohibition period setting process for each set period.

[0038] In Project #10, the control device 5 determines whether it is the timing to set the operation prohibition period. For example, when the operation prohibition period is set and updated once a day, the timing to set the operation prohibition period arrives every 24 hours, such as 0:00 every day. Then, when it is the timing to set the operation prohibition period, the control device 5 proceeds to Project #11, and when it is not the timing to set the operation prohibition period, this flowchart ends.

[0039] In Project #11, the control device 5 refers to the information stored in the storage unit 6, and in the control target period (such as one day) composed of a plurality of unit periods, among the total predicted power loads per unit period predicted in the facility 2 where the water heater 16 is provided, it specifies the predicted second power load per unit period that does not include the predicted first power load of the water heater 16.

[0040] FIG. 3 is a diagram showing an example of the predicted second power load per hour that does not include the predicted first power load of the water heater 16 among the total predicted power loads per hour predicted in the facility 2. In the illustrated example, the predicted second power load is shown as the average value in a plurality of consumer sections 10 included in the facility 2. As shown in the figure, the 24 hours of a day are divided into unit periods of one hour each, and the predicted second power load per hour is specified.

[0041] Next, in Project #12, the control device 5 calculates the median value of the predicted second power load per unit period in the control target period. In the example shown in FIG. 3, the median value is 392 W.

[0042] Next, in Project #13, the control device 5 calculates a threshold value using the median value. In the present embodiment, the control device 5 sets a value larger than the calculated median value as the threshold value.

[0043] 〔Example of calculating the threshold value 1〕 For example, the threshold value is set to a value obtained by adding, to the median value, a value obtained by dividing the unit power load when the water heater 16 provided in the facility 2 operates continuously for one unit period by a predetermined value. The predetermined value is, for example, a value in the range of 5 to 50.

[0044] For example, when the median value is 392 W and the water heater 16 is operated throughout a unit period of 1 hour, the unit power load (average power consumption per hour) is 500 W, and the predetermined value is 10, the threshold value becomes 442 W as shown in Equation 1 below.

[0045] Threshold value = 392 W + 500 W ÷ 10 = 442 W ··· (Equation 1)

[0046] 〔Example of calculating threshold value 2〕 Alternatively, the threshold value is set to a value obtained by dividing the unit power load when the water heater 16 provided in Facility 2 is operated throughout the unit period by the predetermined value, and then multiplying the result by the ratio of the number of consumer sections 10 in which the water heater 16 is provided to the total number of consumer sections 10 provided in Facility 2, and adding the product to the median value.

[0047] For example, when the median value is 392 W, the unit power load (average power consumption per hour) when the water heater 16 is operated throughout a unit period of 1 hour is 500 W, the predetermined value is 10, and the ratio of the number of consumer sections 10 in which the water heater 16 is provided (e.g., 10) to the total number of consumer sections 10 provided in Facility 2 (e.g., 20) is 0.5 (= 10 / 20), the threshold value becomes 417 W as shown in Equation 2 below.

[0048] Threshold value = 392 W + 500 W ÷ 10 × 0.5 = 417 W ··· (Equation 2)

[0049] Next, in step #14, the control device 5 sets the time zone including the unit period in which the predicted second power load becomes greater than the threshold value as the operation prohibition period. FIG. 4 is a graph showing the relationship between the predicted second power load and the threshold value for each unit period. As shown in the figure, when the threshold value calculated in the example of calculating the threshold value 2, which is 417 W, is adopted, the time zones composed of unit periods in which the predicted second power load becomes greater than the threshold value are from 7:00 to 9:00 and from 16:00 to 23:00. As a result, the control device 5 sets the time zones from 7:00 to 9:00 and from 16:00 to 23:00 as the operation prohibition periods.

[0050] Then, the control device 5 transmits the set operation prohibition period to the individual control units 19 of the plurality of customer sections 10. As a result, the water heaters 16 in each customer section 10 will not operate from 7:00 to 9:00 and from 16:00 to 23:00. And in the example shown in FIG. 4, for example, the individual control unit 19 sets a scheduled operation period for performing the heating operation of the heating unit 17 during a period such as from 14:00 to 15:00 when the predicted second power load is smaller than the threshold value. As a result, even if the power consumption for the heating operation in the heating unit 17 increases during the scheduled operation period, it is possible to avoid the total power load of the facility 2 from becoming particularly large.

[0051] As described above, among the total predicted power loads per unit period predicted in the facility 2 where the water heater 16 is provided, the predicted second power load per unit period that does not include the predicted first power load of the water heater 16 is greater than a predetermined threshold value set to a value greater than the median value of the predicted second power loads per unit period during the control target period. The time zone including the unit period is set as the operation prohibition period for prohibiting the heating operation of the heating unit 17. That is, since the water heater 16 will not operate during the unit period when the predicted second power load is relatively large, it is possible to avoid the total power load of the facility 2 from becoming even larger due to the operation of the water heater 16 during the unit period when the predicted second power load is relatively large. Therefore, even in a tariff system where the electricity tariff increases as the power load per unit period of the facility 2 increases, an increase in the electricity tariff can be suppressed. Also, since the above threshold value is set using the median value of the predicted second power loads per unit period during the control target period, among the plurality of unit periods included in the control target period, more than half of the unit periods are not set as the operation prohibition period. That is, since a large number of unit periods during which the water heater 16 may operate can be set, it is expected that the plurality of water heaters 16 will be operated in a time - dispersed manner.

[0052] <Another Embodiment> In the above - described embodiment, a specific example has been given and described for the configuration of the hot - water supply control system, but the configuration can be changed as appropriate. FIG. 5 is a diagram showing the configuration of a hot water supply control system according to another embodiment. As shown in the figure, in the facility 2, one customer section 10 to which power received from the power system 1 is supplied is provided, and a water heater 16 is provided in the customer section 10. Also in this case, the control device 5, in a control target period (for example, one day) composed of a plurality of unit periods, among the predicted power loads for each unit period predicted at the facility 2 where the water heater 16 is provided, specifies the predicted second power load for each unit period that does not include the predicted first power load of the water heater 16, and sets a time period including a unit period in which the predicted second power load for each unit period becomes larger than a predetermined threshold value as an operation prohibition period for prohibiting the heating operation of the heating unit 17. Further, the threshold value is set to a value larger than the median value of the predicted second power loads for each of the plurality of unit periods in the control target period. Note that the individual control unit 19 and the control device 5 may be integrated.

[0053] In the above embodiment, a specific example was given and explained regarding the method for deriving the threshold value, but the derivation method can be set as appropriate.

[0054] In the above embodiment, not only the unit period in which the predicted second power load becomes larger than the threshold value, but also, for example, the unit periods before and after that unit period may be included in the operation prohibition period.

[0055] In the above embodiment, several numerical examples were given, but they are described for illustrative purposes and can be changed as appropriate.

[0056] Note that the configurations disclosed in the above embodiment (including other embodiments, the same applies hereinafter) can be applied in combination with the configurations disclosed in other embodiments as long as no contradiction occurs, and the embodiments disclosed in this specification are illustrative, and the embodiments of the present invention are not limited to this, and can be appropriately modified within the scope not departing from the object of the present invention.

Industrial Applicability

[0057] The present invention can be used in a hot water supply control system that can appropriately set the period during which a hot water heater having a heating unit for heating water using electric power supplied from an electric power system to a facility can operate.

Explanation of Signs

[0058] 1 Electric power system 2 Facility 3 Power receiving equipment 4 Total power measurement unit 5 Control device 6 Storage unit 10 Consumer section 11 Power consumption measurement unit 12 Hot water storage tank 13 Water supply path 14 Hot water outlet path 15 Circulation path 16 Hot water heater 17 Heating unit 18 Electric power load section 19 Individual control section 20 Heat consumption measurement unit

Claims

1. A hot water supply control system for controlling the operation of a hot water heater having a heating unit that heats water using the electric power supplied from an electric power system to a facility, in a control target period composed of a plurality of unit periods, among the total predicted power loads for each unit period predicted in the facility where the hot water heater is provided, excluding the predicted first power load of the hot water heater, specifying the predicted second power load for each unit period, setting a time period including the unit periods in which the predicted second power load for each unit period is greater than a predetermined threshold value as an operation prohibition period for prohibiting the heating operation of the heating unit, The hot water supply control system, wherein the threshold value is set to a value greater than the median value of the predicted second power loads for each of the plurality of unit periods in the control target period.

2. The hot water supply control system according to claim 1, wherein the facility is provided with a plurality of consumer sections to which the electric power received collectively from the electric power system is distributed and supplied, and the hot water heater is provided in at least one of the plurality of consumer sections.

3. The hot water supply control system according to claim 2, wherein the threshold value is set to a value obtained by adding to the median value a value obtained by dividing the unit power load when the hot water heater provided in the facility operates in all of the unit periods by a predetermined value.

4. The hot water supply control system according to claim 2, wherein the threshold value is set to a value obtained by adding to the median value a value obtained by dividing the unit power load when the hot water heater provided in the facility operates in all of the unit periods by a predetermined value and multiplying the result by the ratio of the number of the consumer sections in which the hot water heater is provided to the number of the consumer sections provided in the facility.

5. The hot water supply control system according to claim 3 or 4, wherein the predetermined value is a value in the range of 5 to 50.

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