JP2008096053A - Operation method of storage type hot water supply system and storage type hot water supply system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To restrain deterioration of a function of facilities in power control, and not to contribute to updating of contract demand in an operation method of a storage type hot water supply system having a hot water supply machine taking electric power as a heat source. <P>SOLUTION: This operation method of a storage type hot water supply system includes: a step S21 of setting a margin rate α; a step S1 of setting a demand time limit; a step s2 of calculating the average electric power; a step S3 of time-dividing the demand time limit; a step S6 of estimating the maximum demand power of the facilities at every time division; a step S22 of comparing a margin power value αPp of computed value obtained by multiplying the estimated demand value Pp by a margin rate with a target demand Pmax; and a step S8 of controlling the power of the hot water supply machine 1 so that the margin power value αPp does not exceed the target demand Pmax. The deterioration of function of the facilities in controlling is restrained by power control over the hot water supply machine 1 only, and contribution to updating of contract demand can be surely inhibited by introducing the margin rate α. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for operating a hot water storage hot water supply system and a hot water storage hot water supply system that suppress peak power of maximum demand power in a facility that manages contract power.

  Conventionally, there are various types of power contracts, but it is necessary to receive high-voltage power in facilities that require an electric capacity of approximately 50 kW or more. The contract power in this high voltage power reception is calculated as the largest value among the maximum demand power in each month in the past year including the current month. Here, the maximum demand power is the largest value in a month among all the power used in the facility measured every 30 minutes of the demand time limit. Accordingly, once the maximum value of the used power is updated, the basic charge is continued for at least one year even if the used power value falls below the maximum value. For this reason, to reduce the basic charge, it is necessary to suppress the power consumption so as not to exceed the maximum demand power.

  For this reason, a demand management device generally called a demand controller is commercially available, which predicts a power value (demand value) within a demand time limit, and if there is a possibility of exceeding the maximum value, a lamp display, a buzzer, etc. It will give some kind of alarm. In addition, operation of a load device such as an air conditioner is stopped in conjunction with the demand controller. However, since the power load in an actual facility changes every moment, in such a demand management device, power exceeding the contracted power value may be temporarily used. There were cases where fees increased.

  On the other hand, as a thing which predicts a demand value and prevents this predicted demand value from exceeding a target demand, for example, as shown in Patent Document 1, electric power used by a load other than a heat storage load such as an electric water heater Based on the predicted value, the target power set in advance, and the required power consumption of the heat storage load, the operation of the heat storage load was scheduled within a predetermined time period so that the total power usage does not exceed the target power A demand control device that controls a heat storage load based on control content is known. In demand control of this apparatus, the heat storage load can be controlled only within a time zone scheduled in advance based on the required power consumption, and therefore power control by the heat storage load cannot be automatically performed in real time.

  Moreover, as shown in Patent Document 2, the predicted demand power calculated based on the current power, the average power per unit time, and the remaining time is corrected by a load that can be predicted to run and stop in advance to control power. A maximum demand power monitoring and control device to perform is known. Moreover, as shown in Patent Document 3, the predicted electric energy is calculated based on the fluctuation period of the electric energy, the elapsed time from the start of the electric energy measurement, the increase in the electric energy in the time that goes back by the fluctuation period, the demand time limit, and the like. There is known a demand prediction device that controls the amount of electric power by predicting.

However, in the techniques as disclosed in Patent Documents 2 and 3, since power control is continuously performed within a demand time period, there is a possibility that power is turned on and off at extremely short intervals. For this reason, for example, when the power load is a hot water storage type hot water heater using a heat pump, if the on / off is repeated frequently for power control, the compressor is burdened and the life is shortened. In addition, there is often a waiting time of several minutes from the start of operation to the start of hot water because it takes time to preheat the refrigerant of the heat pump, and in the case of frequent on / off, turn on from off However, there was a case where power was lost by consuming only energy without reaching the hot water.
Japanese Patent Laid-Open No. 9-9502 JP-A-60-245428 Real Shinto-2549868 gazette

  The present invention was made in order to solve the above problems, and in the contract power management of a facility that includes a water heater that uses electric power as a heat source as an electric power load, suppressing a decrease in the function of the facility during power control, And it aims at providing the operating method of the hot water storage type hot-water supply system which does not update the maximum demand electric power of a contract facility, and the hot water storage type hot-water supply system.

  In order to achieve the above object, the invention according to claim 1 is the contract form in which the contract power in each month for one year from the start of electricity use is the largest value among the maximum demand power from the start of electricity use to that month. In the operation method of the hot water storage hot water supply system having a hot water heater using the electric power used in the facility of the facility as a heat source, the step of predicting the average power per predetermined time of the entire contract unit, and the predicted average power is the maximum And a step of controlling the operation of the water heater so as not to contribute to the update of the demand power.

  According to a second aspect of the present invention, in the operation method of the hot water storage type hot water supply system according to the first aspect, a margin rate set for the maximum demand power is added to the predicted average power value for each predetermined time of the contract unit. The operation of the electric power of the hot water heater is controlled based on the calculated value.

  According to a third aspect of the present invention, in the operation method of the hot water storage hot water supply system according to the second aspect, the step of determining the presence or absence of hot water in the hot water storage tank provided in the hot water heater within a predetermined period, and the determination And changing the margin rate within a preset range based on the above.

  According to a fourth aspect of the present invention, there is provided a hot water heater based on a communication unit that communicates with a power measuring unit that measures the power of the entire contract unit, and a power value measured by the power measuring unit obtained through the communication unit. And an operation control means for performing the operation control. The operation control means executes the operation method according to any one of claims 1 to 3.

  According to the first aspect of the present invention, the power control of the hot water heater can suppress the influence of the power control on the overall facility function so that the predicted average power does not contribute to the update of the maximum demand power. Can be prevented from becoming high.

  According to the invention of claim 2, since the maximum demand power that becomes a reference for comparison with the predicted average power can be equivalently reduced by the margin ratio, there is a margin with respect to the maximum demand power that is the actual contract power. Therefore, it is possible to carry out power control, and to reliably prevent the power used from exceeding the maximum demand power.

  According to the invention of claim 3, since the margin ratio can be changed to be optimal in accordance with the presence or absence of hot water in the hot water storage tank, it is possible to reduce the hot water shortage time of the hot water storage tank and increase the contract electric power charge. It is possible to achieve both prevention of becoming.

  According to the invention of claim 4, since the hot water heater operation is controlled based on the measured power value of the entire contract unit, the influence of the power control on the overall facility function is kept low, and the contribution to the update of the maximum demand power is made. It is possible to prevent the contract electric power charge from becoming high.

  An operation method of the hot water storage type hot water supply system according to the first embodiment of the present invention will be described with reference to the drawings. The operation method of the hot water storage type hot water supply system of the present embodiment uses the largest value from the month when electricity is first used to the current month among the maximum demand power for each month in the average power for each time period determined as the contract unit time. In facilities that have a contract form of contract power for each month for one year from the start, the average power (referred to as demand) for each predetermined time (referred to as demand time limit) of the entire contract unit including the water heater is predicted and predicted. In addition, the hot water heater is regularly operated (referred to as demand control) so that the average power (referred to as a predicted demand value) does not contribute to the update of the maximum demand power of the contract facility.

  FIG. 1 shows a configuration of a hot water storage type hot water supply system applied to the present embodiment. This hot water storage type hot water supply system includes a water heater 1 serving as an electric power load and a power source 2 for supplying electric power to the water heater 1. The water heater 1 includes a hot water storage tank 4 for storing hot water, a heat pump unit (HPU) 5 having a plurality of heat pumps for warming and supplying hot water to the hot water storage tank 4, and an electronic control unit for controlling the hot water storage tank 4 and the HPU 5 and the like. (Electronic, control unit, ECU) 6, and a communication unit 7 (communication unit) that communicates the power value measured by the power measurement unit 3 (power measurement unit) separately provided to the facility to the ECU 6 in a wired or wireless manner Have. The power measuring unit 3 measures the power of the entire contract unit in the facility including the power consumption of the power source 2.

  The ECU 6 includes a CPU 8 that controls the entire hot water supply system, an operation control unit 9 (operation control means) that controls the operation of the HPU 5, a hot water detection unit 11 that detects a hot water out of the hot water storage tank 4, and a plurality of power measurement times. The timer unit 12 having the timers (I, II, III, IV) and the remote controller 13 for remotely controlling the ECU 6 are provided. Further, the hot water storage tank 4 and the HPU 5 are pipes 20 (double wires) for passing water having a low temperature and pipelines 21, 22, 23, 24 (black thick lines) for passing hot water as pipelines for supplying water and hot water. ). This pipe 20 has a bypass valve 25 that bypasses the flow of water and a water stop valve 26 that stops supply water, and the pipe 21 has a relief valve 27 that partially discharges hot water and a temperature control valve 28 for temperature adjustment. The pipe 22 includes a pressure reducing valve 29 and a water stop valve 26 for reducing the water pressure (or hot water pressure). The pipes 23 and 24 supply hot water (up to 90 ° C.) from the hot water storage tank 4 and set hot water whose temperature is adjusted by the temperature control valve 28 to the hot water tap 30 and the mixing tap 31 provided at the end of each pipe. Then, hot water and temperature-controlled hot water are respectively output from each plug. A hot water outlet side and a water inlet side of the hot water storage tank 4 are respectively provided with a temperature sensor 32 for measuring the temperature of the hot water and a flow rate counter 33 for measuring the amount of water. The temperature sensor 32 is connected to the hot water detection unit 11, and the hot water detection unit 11 detects the hot water using the temperature sensor 32 at the upper part of the hot water storage tank 4. Here, the hot water out means that the temperature of the hot water in the hot water storage tank 4 is lowered and the hot water is in a water state.

  In the operation of the hot water storage type hot water supply system having the above configuration, the hot water heater 1 is operated and controlled in the following three stages. In the first stage, first, the average power is calculated at regular time intervals Ts (minutes) immediately after the demand time limit (generally 30 minutes) is updated, and the second stage is the demand time of the average power calculation. The power value of the water heater 1 that can be consumed within the time limit is calculated, and in the third stage, the predicted demand value Pp at that time is the maximum demand power of the contract power (the maximum power value in the past year (30-minute average)) That is, when the target demand Pmax is exceeded, the operation is stopped for the time interval Ts (minutes).

  For this reason, the power measuring unit 3 measures the power consumption of the entire contract unit of the facility including the HPU 5 serving as the power load of the water heater 1 and other power loads of the facility. The measured power value is transmitted from the communication unit 7 to the CPU 8 of the ECU 6. The CPU 8 sets the time unit for obtaining the average power from the power value as the demand time period T1 (30 minutes) of the contract unit time, and calculates the average power (demand) for each demand time period T1. Further, the CPU 8 obtains the average power Pave from the update to the present time at every predetermined time interval Ts obtained by further dividing the demand time period T1 (here, T1 is divided into 6 for 5 minutes). This divided time interval Ts is a time interval for determining whether the HPU 5 is operating or stopped. Further, in the HPU 5 that requires time for preheating the refrigerant, the time interval Ts is selected to be 5 minutes in consideration of the case where several minutes are required from the start of normal operation to the start of hot water.

  In addition, the CPU 8 controls the timer I that measures the elapsed time t1 since the power value update and the timer II that measures the time interval Ts in the timer unit 12, and the maximum demand predicted power of the facility within the demand time limit T1 (30 minutes). (Pp) (predicted demand value) is predicted every Ts time. Therefore, first, at the time of calculating the average power Pave, the power value of the water heater 1 that can be consumed in the remaining time within the demand time limit is calculated. The power consumption of the water heater 1 is substantially determined by the power consumed by the HPU 5 that uses a large amount of power. The demand predicted power for the remaining time (30-t1) from the current time t1 of the demand time period T1 of the power used by the HPU 5 is obtained as Ph (30-t1) / 30. Here, Ph is determined by the power consumption per demand time period of all heat pumps used in the HPU 5, and is the maximum predicted power consumption per demand time period (30 minutes) of the HPU 5.

Next, the predicted demand value Pp in the demand time period of the entire contract unit of the facility is obtained. The predicted demand value Pp is obtained by adding the demand predicted power Ph (30-t1) / 30 consumed in the remaining time of the demand time limit of the HPU 5 to the average power Pave at the current time t1 after the demand time period update. As a result, the predicted demand value Pp is represented by the following one expression.
Pp = Pave + Ph (30−t1) / 30 (1)
Thus, the predicted demand value Pp can be easily obtained from the average power Pave and the demand predicted power Ph (30-t1) / 30 of the HPU 5. Further, the CPU 8 compares the predicted demand value Pp serving as the contract power with the maximum demand power (30-minute average value) Pmax [kW] (referred to as target demand) for the past one year, and this predicted demand value Pp sets the target demand Pmax. The operation control unit 9 is controlled so as not to exceed, and the operation control unit 9 switches the HPU 5 on and off to control the operation of the water heater 1.

  As described above, the operation method of the hot water storage type hot water supply system of the present embodiment predicts the maximum demand power for each demand time period (30 minutes), and the power load of the water heater 1 so that the predicted value does not exceed the target demand Pmax. The operation of the HPU 5 is controlled. Hereinafter, the operation method of this hot water storage type hot water supply system will be described with reference to the flowchart of FIG.

  In FIG. 2, first, after updating the demand time limit, the CPU 8 sets the elapsed time t1 of the timer I of the timer unit 12 to zero (S1), and sets the average power Pave calculated from the power value of the power measuring unit 3 to zero. Then, the time t2 for obtaining the average power Pave in the timer II of the timer unit 12 is set to zero (S3). Next, the CPU 8 calculates the average power Pave based on the power value of the power measuring unit 3 (S4), and when the time t2 is less than Ts (NO in S5), the CPU 8 returns to Step 4 and returns to the average power Pave in the Ts period. When the time t2 is larger than Ts (YES in S5), the average power Pave calculated in step 4 and the demand prediction of the average power within the remaining demand time period (30-t1) of the HPU 5 are calculated. The predicted demand value Pp is obtained from the sum of the electric power Ph (30-t1) / 30 (S6), and the predicted demand value Pp is compared with the Pmax of the target demand. If the predicted demand value Pp is large (YES in S7) The CPU 8 issues a stop command for the HPU 5 (S8). If NO in step 7, the CPU 8 cancels the stop command for the HPU 5 (S9).

If the time t1 is less than the demand time limit of 30 minutes (NO in S10), the process returns to step 3, resets t2 to zero, and repeats step 3 to step 10 again. If YES in step 10 (when the demand time period of 30 minutes has elapsed), the process returns to step S1, resets t1 to zero, and proceeds to measurement in the next demand time period.

  FIG. 3 shows, as an example of demand control based on the above flowchart, the relationship between the change in the predicted demand value Pp for each time interval Ts (5 minutes) in the demand time limit of 30 minutes and the control command. In FIG. 3, since the predicted demand value Pp is predicted to exceed the target demand Pmax when the elapsed time t1 is between 10 minutes and 15 minutes, the CPU 8 issues a stop command for the HPU 5 at t1 = 10 minutes. , If it is predicted that Pp exceeds Pmax even at t1 = 15 minutes, HPU5 is continuously stopped between 15 minutes and 20 minutes. When the predicted demand value Pp between 20 minutes and 25 minutes at t1 = 20 minutes is predicted to be equal to or less than Pmax, the HPU 5 is restarted by the operation command from the CPU 8.

  Thus, according to the operation method of the hot water storage type hot water supply system of the present embodiment, this prediction based on the predicted demand value Pp predicted for each time interval Ts obtained by dividing the demand time period (30 minutes) for each demand time period. By determining at every Ts so that the demand value Pp does not exceed the target demand Pmax and stopping or releasing the stop of the HPU 5, the hot water storage hot water supply system is finely controlled so as not to exceed the maximum demand power of the contract power. be able to. Thereby, it is possible to prevent the power charge from exceeding the contract charge, and economical power control is possible. The power control of the water heater 1 can be automatically controlled in real time for each Ts, not in a limited time zone.

Moreover, in the hot water storage type hot water supply system of this embodiment, since the hot water storage capacity of the hot water storage tank 4 of the water heater 1 is large (in this case, 370 L), the temperature of the hot water suddenly decreases even if stopped instantaneously. Without affecting the operation of the hot water supply function. In addition, since power control can be performed without stopping other power loads (for example, lighting devices) in the operating state, it is possible to prevent functional degradation of facilities having many power loads in facilities accompanying power control. Therefore, since the facility as a whole is less affected by the power control, it is possible to suppress a decrease in the function of the facility during the power control, to prevent the maximum demand power from being updated, and to reduce the power charge.

  Moreover, in the heat pump type water heater 1 of the present embodiment, if the on-off is repeated frequently, a load may be applied to the compressor to shorten the life. However, here, by setting the operation switching interval as long as 5 minutes of the Ts time, it is possible to suppress the frequency of the operation switching and suppress the decrease in the pump life. Furthermore, in this heat pump type hot water heater 1, since it takes time to reheat the refrigerant, it often takes several minutes from the start of normal operation to the start of tapping. However, in the power control of this embodiment, since the operation stop time interval is set to 5 minutes, the energy efficiency of the HPU 5 can be increased and used, and the power control is possible. It is possible to reduce the power consumption at. Further, the power measurement unit 3 can be controlled by the CPU 8 by making the communication unit 7 bidirectional communication. Moreover, the electric power measurement part 3 which measures the electric power of the whole plant | facility may be in the hot water storage type hot-water supply system 1 itself, and may exist outside.

  Next, an operation method of the hot water storage type hot water supply system according to the second embodiment of the present invention will be described with reference to FIG. The operation method of the hot water storage type hot water supply system of the present embodiment and the hot water storage type hot water supply system to which this operation method is applied are basically the same as those of the first embodiment, and the predicted average for each predetermined time of the contract unit. Operation control is performed on the power of the water heater based on a calculated value obtained by multiplying the power value by the margin rate α set for the maximum demand power (target demand) as the contract power.

  In FIG. 4, first, the CPU 8 sets a margin rate α for the target demand Pmax (S21). This margin rate α is normally set to a value larger than 1. When α = 1, the result is the same as in the first embodiment. Steps 1 to 6 after the setting of the margin rate α are the same as those in the first embodiment, and the CPU 8 calculates the predicted demand value Pp in Step 6 and then calculates the predicted demand value Pp. Using the calculated value Pp × α multiplied by the margin rate α as a margin power value, the margin power value αPp is obtained by calculation, and the obtained margin power value αPp is compared with the target demand Pmax (S22). The following steps S8 to S10 are the same as the procedure of the first embodiment, and the CPU 8 controls the HPU 5 based on the comparison determination of step 22. In this procedure, since the predicted demand value Pp is set to the marginal power value αPp, the judgment formula Pp × α> Pmax in step 22 is replaced with Pp> (Pmax / α). On the other hand, the target demand Pmax is set small. Therefore, the HPU 5 can be stopped early with a margin before the predicted demand value Pp exceeds the target demand Pmax. Thereby, it is possible to reliably control the predicted demand value Pp so as not to exceed the target demand Pmax.

  As an example of demand control based on the flowchart shown in FIG. 5, as in the first embodiment, a change in the predicted demand value Pp for each time interval Ts (5 minutes) in the demand time limit of 30 minutes and a control command from the CPU 8 The relationship is shown. As shown in the graph of FIG. 5, the water heater 1 is controlled to stop the HPU 5 when it is predicted that Pp on the vertical axis exceeds Pmax / α lower than Pmax. Therefore, if the predicted demand value Pp between 5 minutes and 10 minutes is predicted to exceed Pmax / α at the elapsed time t1 = 5 minutes, the CPU 8 issues a stop command for the HPU 5 at that time. In addition, if it is predicted that Pp exceeds Pmax / α in each of 5 minutes from 10 minutes to 20 minutes, HPU 5 is stopped even if t1 is between 10 minutes and 20 minutes. On the other hand, if it is predicted that Pp will be Pmax / α or less during 20 minutes to 25 minutes at t1 = 20 minutes, the CPU 8 issues an operation command at that time. Furthermore, if it is predicted that Pp will be equal to or less than Pmax / α for 5 minutes (Ts) of 20 to 30 minutes, the operation is continued.

  Thus, by providing the marginal power value αPp, the target demand becomes the same as that set as low as Pmax / α, and the HPU 5 can be controlled by issuing the stop command for the HPU 5 early, so that the target demand is surely achieved. Demand control can be performed so as not to exceed Pmax, and an increase in usage charges can be suppressed.

  Next, demand control when the value of the margin rate α is changed will be described with reference to FIGS. FIGS. 6 and 7 measure the power data and hot water data at the restaurant A and the store B of the restaurant shown in Table 1 above, and based on the results, a comparison between when the demand control is performed and when the demand control is not performed The result of the simulation is shown.

  In this simulation, the purpose is to reduce the basic charge of the water heater 1 by demand control, and in order to watch over the hot water supply which is an important basic function of the water heater 1 is not stopped, the time when the hot water breaks out is also simulated. That is, the change in the basic charge with respect to the margin rate α and the hot water run-out time are used as simulation items. When there is no demand control and when the demand control is performed with the allowance rate α introduced, the difference between the basic rate and the hot water The difference in cutting time was calculated, and these two items were used for judgment for demand driving evaluation.

  Here, the basic charge difference (yen / month) is the basic charge difference per month when the demand operation is not performed and the hot water run-out time difference (h / d) is 1 when the demand operation is not performed. The difference in hot water run-out time (h) per day (d), that is, the time difference at which the amount of hot water in the hot water storage tank 4 becomes zero was used. Since there is no past maximum power data in this calculation, the maximum power is updated from the start of the calculation. The difference in the average value per day was taken. Each specification shown in Table 1 was used as a simulation condition for performing this calculation.

  Table 1 shows examples of specifications such as the number of heat pumps in store A and store B, heat pump power consumption (per demand time limit), maximum hot water storage capacity of hot water storage tanks, power factor of load equipment, and basic power unit price of contract power Is shown. In this simulation, the number of heat pumps is set to an appropriate number for each store by pre-calculation (2 units for store A and 3 units for store B), and the basic rate is calculated as follows: basic rate = unit price × contract power X <185-Power factor> / 100, and the initial value of the target demand Pmax of the maximum demand power was calculated as 0.

  In FIGS. 6 and 7, when α is individually changed, the basic charge difference (diamond-shaped broken line) and the run-out time difference (square-shaped broken line) between the case where there is no demand control and the case where demand control is introduced by α ) On the vertical axis and α on the horizontal axis. As shown in these graphs, when the margin rate α is increased, the estimated demand value Pp is apparently estimated to be large (αPp), so the HPU 5 is stopped with a margin for the limited power and the power consumption is reduced. Thus, although the power charge can be reduced, the hot water run-out time increases because the number of times the HPU 5 is stopped increases. On the contrary, if the margin rate α is lowered, the predicted demand value Pp becomes smaller. On the contrary, the number of stops of the HPU 5 decreases, the hot water run-out time decreases, and the operation time of the HPU 5 increases accordingly, and the basic charge The difference will be reduced and the effect of fee reduction will fade. As can be seen from the graphs of FIGS. 6 and 7, if α is in the range of 1 or more and 1.05 or less, the basic charge difference can be increased to reduce the power charge, and the hot water run-out time difference is hardly changed. It can be seen that the time for running out of hot water can be reduced.

  Table 2 shows the optimum value of the margin rate α based on the result of the simulation and the basic charge difference and hot water run-out time difference at that time. As shown in Table 2, as a result of calculating the basic charge difference and the hot water run time difference for each margin rate α, the optimum α value at the store A is 0.98, and the hot water run time difference at that time is 0, the basic charge. The difference was 5,490 yen / month. On the other hand, in the store B, the optimum value of α was 1.05, the difference in outage time was 0, and the basic charge difference was 7,304 yen / month. Thus, it turns out that the optimal value of (alpha) changes with electric power consumption and a tapping pattern. However, as described above, α is preferably 1 or more and 1.05 or less in order to surely reduce the basic charge and reduce the hot water running time.

  Thus, by introducing the margin rate α and setting α to 1 or more and 1.05 or less, it is possible to suppress the hot water run-out time and reduce the basic charge. In addition, if the power data and hot water volume data of the facility are measured in advance and the optimum value of α is obtained in advance by simulation, the target demand is surely exceeded by controlling the power of the hot water heater 1 using this α. Therefore, it is possible to perform suitable demand control with little hot water shortage.

  According to the operation method of the hot water storage hot water supply system of the second embodiment, the margin demand α is introduced, and the target demand Pmax of the maximum demand power serving as a reference for comparison with the predicted demand value Pp that is the predicted average power is Since it can be reduced equivalently by the margin rate, it is possible to control power with a margin against the maximum demand power that is the actual contract power, and to ensure that the power used exceeds the contract power. Can do.

  Next, an operation method of the hot water storage type hot water supply system according to the third embodiment of the present invention will be described with reference to FIG. The operation method of the hot water storage type hot water supply system of this embodiment and the hot water storage type hot water supply system to which this operation method is applied are basically the same as those of the second embodiment, and is provided in the hot water heater 1 within a predetermined period. In addition, it is determined whether or not the hot water tank 4 has run out, and the margin rate α is automatically changed within a preset range based on this determination.

In addition to the second embodiment, the operation method of the hot water storage type hot water supply system of the present embodiment enables α to be automatically set. Therefore, as a learning condition for α,
(1) α range 1.00 ≦ α ≦ 1.05 (initial value 1.05)
(2) In case of running out of hot water in the past one day α = α−0.01
(3) When the hot water has not run out in the past 7 days α = α + 0.01
It was. As a result, when there is a hot water shortage, the HPU 5 can be stopped less and hot water shortage can be reduced by reducing α and reducing the marginal power value αPp. When the state without running out of hot water continues for a long time, it is determined that there is a margin in the hot water storage state, and there is little occurrence of hot water even when the HPU 5 is stopped, and α is increased to increase the marginal power value αPp. As a result, Pmax / α can be reduced, and the HPU 5 can be frequently stopped to reduce power consumption. For the range of α, referring to the simulation data in FIGS. 6 and 7, the lower limit of α is set to 1.00 or more so as to lower the basic charge, and the upper limit of α is set so that hot water does not frequently occur. It is set to 1.05 or less. Also, the initial value is set to 1.05 so that the marginal power value αPp does not exceed the target demand Pmax from the beginning, and is set to the higher of the range of α.

  An operation method of the hot water storage type hot water supply system of the present embodiment based on the learning conditions will be described with reference to the flowchart of FIG. In FIG. 8, first, the CPU 8 sets α = 1.05 as the initial value of the margin rate α with respect to the target demand Pmax (S21). After the demand time limit is updated, the elapsed time t3 is set to zero by the timer III of the timer unit 12 (S31), and the elapsed time t4 is set to zero by the timer IV (S32). The following steps 1 to 10 are the same as the procedure of the second embodiment. When t4 of the timer IV is less than one day (NO in S33), t1 is reset to 0 (S1), and in the case of YES in Step 33, it is determined whether or not hot water has run out in the past one day, If the hot water runs out (YES in S34), and if α> 1 (YES in S35), α is reduced to (α−0.01) (S36), and the process returns to step 32, and S35. In the case of NO, α is not changed and the process returns to step 32, and in both cases, t4 is reset to 0 by the timer IV. Next, in the case of NO in step 34, if the elapsed time of t3 of timer III is less than 7 days (NO in S37), the process returns to step S32. If YES in step 37, if no hot water has run out in the past 7 days (YES in S38), if α <1.05 (YES in S39), α is increased to (α + 0.01) ( S40), return to step 31, and if NO in S39, return to step 31 without changing α, and also return to step 31 if NO in step 39, both reset t3 to 0 in timer III Then, the steps after step 31 are repeated.

  FIG. 9 shows an example of a change in the margin rate α at the store A and the store B calculated by the simulation based on the flowchart. As shown in FIG. 9, by automatically controlling both the demand control and the hot water control, the margin rate α at the store A (dotted line) and the store B (solid line) is between 1.0 and 1.05. Changed. Table 3 shows the optimum values of the margin rates α in the store A and the store B by the simulation at this time, and the basic charge difference and the hot water time difference at that time.

  According to the comparison between Table 3 and Table 2, when α is automatically set, the difference in basic charges is approximately the same for both stores compared to the case where α is set individually and simulation is performed. There wasn't. Moreover, both hot water run time differences were 0.01 (h / d), and there was almost no difference. As a result, even when α is automatically set, the same effect as the basic charge difference and hot water time difference at the optimum values obtained by individually changing α can be obtained, and the basic charge is hardly increased with almost no increase in hot water time. Was confirmed to be reduced to the same extent.

  According to the operation method of the hot water storage type hot water supply system of the third embodiment, the presence or absence of hot water in the hot water storage tank 4 provided in the hot water heater 1 within a predetermined period is determined, and the margin rate is determined based on this determination. α can be automatically changed within a preset range. As a result, the margin rate α can be automatically set to an optimum value, and the power control can be performed while automatically reducing the basic charge and reducing the hot water running time.

  According to the operation method of the hot water storage type hot water supply system according to the various embodiments described above, the power control of the entire contract unit of the facility including the hot water heater 1 is performed by the power control of only the hot water heater 1 that is less affected by the deterioration in function even in an instantaneous stop. Since it can be performed, the influence of the demand control on the overall facility function can be kept low, the water heater can be operated so as not to contribute to the renewal of the maximum demand power, and the contract power charge can be reduced. In addition, since power control based on the predicted demand value Pp is performed for each time interval Ts further divided within the demand time period, frequent on-off operation can be avoided. In particular, in the heat pump type hot water heater 1, the compression is performed. It is possible to suppress the life deterioration of the machine and reduce energy loss.

  Further, by setting a margin rate α for the target demand Pmax and controlling the operation of the water heater based on a comparison between the target demand Pmax and a calculated value αPp obtained by multiplying the margin rate α by the predicted demand value Pp. Excessive contract power in power can be reliably suppressed. Furthermore, the learning rate is changed so that the margin rate α is optimized in accordance with the presence or absence of hot water in the hot water storage tank 4, thereby automatically reducing both hot water consumption in the hot water storage tank 4 and reducing the electricity bill. be able to.

The block diagram of the hot water supply system in the operating method of the hot water storage type hot water supply system which concerns on the 1st Embodiment of this invention. The flowchart figure of the said operating method. The figure explaining the relationship between the change of the predicted demand power within the demand time limit based on the said operation method, and a control command. The flowchart figure of the operating method of the hot water storage type hot-water supply system which concerns on the 2nd Embodiment of this invention. The figure explaining the relationship between the predicted demand power change within the demand time limit based on the said operation method, and a control command. The graph which shows the relationship between the margin rate in store A based on the said driving | operation method, a basic charge difference, and a hot water run-out time difference. The graph which shows the relationship between the margin rate in the store B based on the said driving | operation method, a basic charge difference, and a hot water run time difference. The flowchart figure of the operating method of the hot water storage type hot-water supply system which concerns on the 3rd Embodiment of this invention. The figure which shows the example of the change of the margin rate by the said operating method.

Explanation of symbols

1 Water heater 3 Electric power measurement unit (electric power measurement means)
4 Hot water storage tank 5 Heat pump unit 7 Communication section (communication means)
9 Operation control unit (operation control means)

Claims (4)

A hot water heater that uses the power used in the facility of the contract form in which the contract power for each month of the year from the start of electricity use is the largest of the maximum demand power from the start of electricity use to that month. In the operation method of the hot water storage type hot water supply system having,
Predicting the average power of the entire contract unit for a given time;
And a step of operating the hot water heater so that the predicted average power does not contribute to the update of the maximum demand power.   The power control of the water heater is controlled based on a calculated value obtained by multiplying a predicted average power value for each predetermined time in a contract unit by a margin rate set for the maximum demand power. The operation method of the hot water storage type hot water supply system according to 1. Determining the presence or absence of hot water in a hot water storage tank provided in a water heater within a predetermined period;
The operation method of the hot water storage type hot water supply system according to claim 2, further comprising a step of changing the margin rate within a preset range based on the determination. A communication means for communicating with a power measuring means for measuring the power of the entire contract unit;
Operation control means for controlling the operation of the water heater based on the power value measured by the power measurement means obtained via the communication means,
The said operation control means performs the driving | operation method as described in any one of Claims 1 thru | or 3. The hot water storage type hot-water supply system characterized by the above-mentioned.

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