Hot water storage system

Abstract

To provide a hot water supply system that can minimize energy loss. [Solution] The hot water storage and supply system (1) includes a main heat source unit (10) that heats the hot water in the hot water storage tank, a hot water outlet passage (27) for the hot water in the hot water storage tank, an auxiliary heat source unit (40) to which the hot water is supplied, a hot water supply means (55) that pours hot water from the auxiliary heat source unit through a hot water supply passage (54) connected to the bathtub (3), a means for detecting the amount of hot water heat dispensed via the auxiliary heat source unit, and a control means (29) that predicts the required amount of heat for each time period based on the hot water output record including the amount of hot water heat dispensed, and stores the total required amount of heat for a predetermined number of time periods. The control means determines whether or not to include the predicted amount of hot water heat dispensed in the required amount of

Description

Technical Field

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[0001] The present invention relates to a household hot water storage and supply system that predicts future hot water output based on past hot water output records and stores hot water in a hot water storage tank according to this prediction.

Background Art

[0002] Conventionally, a hot water storage and supply system that uses a heat pump type heat source machine as a heat source machine to perform a hot water storage operation of storing heated hot water in a hot water storage tank and uses the hot water stored in this hot water storage tank for hot water supply or pouring hot water into a bathtub has been widely used. For example, there are types that use late-night electricity set at a lower price than during the day to store hot water for the next day the previous night, and types that store the amount of heat required for future hot water supply predicted based on past hot water output records before hot water supply is used.

[0003] For example, Patent Documents 1 and 2 disclose a technique of calculating the implementation probability or correlation coefficient of hot water filling from the relationship between the load state and hot water filling in a specific time zone in the past, and predicting the presence or absence of hot water filling based on the implementation probability or correlation coefficient of hot water filling that matches or is similar to the load state on the current day. If the presence or absence of hot water filling is as predicted, it is possible to store hot water efficiently so that there is no waste of hot water that is stored but not used or no shortage of hot water.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] In Patent Documents 1 and 2, if the presence or absence of hot water differs from the prediction, waste or a shortage of hot water will occur, and a shortage of hot water is particularly undesirable as it prevents the supply of hot water. For this reason, a hot water storage and supply system is widely used in which, for example, a heat pump type main heat source unit stores hot water to avoid waste, and in the event of a shortage of hot water, heated water is supplied by, for example, a combustion type auxiliary heat source unit.

[0006] It is difficult to accurately predict how users will use hot water, and some waste or depletion of hot water is inevitable even with hot water storage. However, there is a need to minimize the energy loss associated with the waste of not storing enough hot water for filling the bathtub (heat for pouring) and the energy loss associated with depleting the hot water supply when pouring without storing enough hot water.

[0007] Therefore, the present invention aims to provide a hot water storage and supply system that can reduce energy loss. [Means for solving the problem]

[0008] The hot water storage and supply system of the invention of claim 1 comprises a hot water storage tank for storing hot water, a main heat source unit for heating the hot water in the hot water storage tank, a hot water outlet passage for dispensing hot water from the hot water storage tank, an auxiliary heat source unit to which the hot water dispensed from the outlet passage is supplied, a hot water pouring means for pouring hot water from the auxiliary heat source unit through a hot water pouring passage connected to a bathtub, a hot water outlet heat amount detection means for detecting the amount of hot water heat dispensed through the auxiliary heat source unit, and a means for predicting the required amount of heat for each time period divided into predetermined time intervals based on the amount of hot water heat dispensed detected by the hot water outlet heat amount detection means and past hot water dispensing records including the time of dispensing, and controlling the system to store the sum of the required amounts of heat for a predetermined number of time periods. In a hot water storage and supply system equipped with a control means, the control means is configured to determine whether or not to include the predicted hot water supply heat amount in the required heat amount when summing the predicted hot water supply heat amount and the predicted hot water supply heat amount for each time period, which are predicted based on the hot water supply performance by the hot water supply means and the hot water supply performance other than hot water supply included in the hot water output performance. This determination is made based on the expected value of the hot water storage loss, which is the expected value of the energy loss if the predicted hot water supply heat amount is not stored by the main heat source and hot water supply is not performed, and the expected value of the hot water supply loss, which is the expected value of the energy loss if the predicted hot water supply heat amount is not stored and hot water supply is performed by the auxiliary heat source.

[0009] According to the above configuration, the system determines whether or not to include the predicted heat amount for hot water supply in the required heat quantity and store it, based on the expected energy loss when the predicted heat amount for hot water supply is not stored and hot water supply is not performed (expected storage loss) and the expected energy loss when the predicted heat amount for hot water supply is performed without storing it (expected hot water supply loss). Since the decision is made according to the expected energy loss, for example, by selecting the option with the smaller expected energy loss, the energy loss of the hot water supply system can be reduced.

[0010] The hot water storage and supply system of the invention of claim 2 is characterized in that, in the invention of claim 1, the control means determines that the predicted heat amount for hot water supply should be included in the required heat amount when the expected value of hot water storage loss is less than or equal to the expected value of hot water supply loss, and determines that the predicted heat amount for hot water supply should not be included in the required heat amount when the expected value of hot water storage loss is greater than the expected value of hot water supply loss. According to the above configuration, if the expected value of hot water storage loss is less than or equal to the expected value of hot water supply loss, the required amount of heat (predicted heat for supply and predicted heat for hot water supply), including the predicted heat for supply, is stored. If the expected value of hot water storage loss is greater than the expected value of hot water supply loss, the required amount of heat (predicted heat for hot water supply), excluding the predicted heat for supply, is stored. Therefore, since the option with the smaller expected value of energy loss with respect to hot water supply is selected, the energy loss of the hot water storage and hot water supply system can be reduced.

[0011] The hot water storage and supply system of the invention of claim 3 is characterized in that, in the invention of claim 1 or 2, the expected value of hot water storage loss and the expected value of hot water supply loss are calculated, respectively, by using a hot water supply rate obtained by dividing the number of days on which hot water was supplied during a reference period of a predetermined length by the number of days in this reference period, and a hot water supply utilization rate which is the ratio of the average daily amount of hot water supplied during the reference period to the predicted amount of hot water supplied. According to the above configuration, the expected hot water storage loss and the expected hot water supply loss are calculated using the hot water supply implementation rate based on actual hot water output during the reference period and the hot water utilization rate, which is the ratio of the average daily hot water supply heat to the predicted hot water supply heat. Since it is possible to determine whether or not to store the predicted hot water supply heat using the expected hot water storage loss and the expected hot water supply loss, which reflect the actual usage patterns, the energy loss of the hot water storage and supply system can be reduced. [Effects of the Invention]

[0012] According to the hot water storage and supply system of the present invention, energy loss can be reduced. [Brief explanation of the drawing]

[0013] [Figure 1] This is a diagram showing the configuration of a hot water storage and supply system according to an embodiment of the present invention. [Figure 2] Figure 1 is a diagram showing the configuration of the auxiliary heat source unit. [Figure 3] This is a flowchart for predicting the required heat output. [Figure 4] This figure shows an example of predicting the required heat quantity based on actual hot water output data.

Best Mode for Carrying Out the Invention

[0014] Hereinafter, embodiments for carrying out the present invention will be described based on examples.

Example

[0015] First, the hot water storage and supply system 1 will be described based on FIG. 1. The hot water storage and supply system 1 includes a heat pump type main heat source machine 10, a hot water storage unit 20 having a hot water storage tank 21, and an auxiliary heat source machine 40. The auxiliary heat source machine 40 is, for example, a combustion type heat source machine, and heats the hot water supplied from the hot water storage unit 20 through the hot water passage 41 according to its temperature, or supplies it without heating, for example, to a hot water faucet 8 connected to the hot water supply passage 42.

[0016] At the lower part of the hot water storage tank 21, a main heat source machine forward passage 23 provided with a pump 22 is connected to supply the hot water in the hot water storage tank 21 to the main heat source machine 10. At the upper part of the hot water storage tank 21, a main heat source machine return passage ²⁴ is connected to return the hot water heated by the main heat source machine 10 to the hot water storage tank 21. In the middle of the main heat source machine return passage 24, a switching valve 25 for switching the flow path of the hot water is arranged, and a return branch passage 24a branched from the main heat source machine return passage 24 by the switching valve 25 is connected to an upstream side portion of the pump 22 in the main heat source machine forward passage 23.

[0017] A plurality of hot water storage temperature sensors 21a to 21d are arranged in the hot water storage tank 21, and the temperature and the amount of stored hot water, that is, the stored heat amount of the hot water stored in the hot water storage tank 21 can be detected. An upstream side portion of the switching valve 25 in the main heat source machine return passage 24 is provided with a return temperature sensor 24b for detecting the temperature of the hot water heated by the main heat source machine 10. For example, when the detected temperature of the return temperature sensor 24b is low immediately after the start of the main heat source machine 10, the switching valve 25 is switched from the hot water storage tank 21 side to the return branch passage 24a side, and the hot water is circulated without returning to the hot water storage tank 21 until it can be sufficiently heated.

[0018] At the bottom of the hot water storage tank 21, a water supply passage 26 for supplying make-up water as indicated by the arrow CW is connected. At the top of the hot water storage tank 21, a hot water discharge passage 27 for discharging the hot water in the hot water storage tank 21 outside the hot water storage unit 20 is connected. A water supply branch passage 26a branched from the middle of the water supply passage 26 is connected to a mixing valve 28 disposed in the middle of the hot water discharge passage 27.

[0019] A water supply temperature sensor 26b for detecting the temperature of the make-up water (water supply temperature) supplied from the water supply passage 26 is disposed in the water supply passage 26. In the hot water discharge passage 27, a hot water discharge flow sensor 27a, a hot water storage tank hot water discharge temperature sensor 27b, and a hot water discharge temperature sensor 27c are disposed. The hot water discharge flow sensor 27a detects the hot water discharge flow rate from the hot water storage unit 20. The hot water storage tank hot water discharge temperature sensor 27b detects the temperature of the hot water discharged from the hot water storage tank 21 (hot water storage tank hot water discharge temperature). The hot water discharge temperature sensor 27c detects the hot water discharge temperature from the hot water storage unit 20. Based on the hot water discharge flow rate detected by the hot water discharge flow sensor 27a and the hot water discharge temperature detected by the hot water discharge temperature sensor 27c, the hot water heat quantity from the hot water storage unit 20 is detected (calculated).

[0020] The hot water discharge passage 27 of the hot water storage unit 20 and the water supply port 40a of the auxiliary heat source machine 40 are connected by a hot water passage 41. A hot water supply passage 42 connected to the hot water supply tap 8 is connected to the hot water supply port 40b of the auxiliary heat source machine 40. The hot water discharged from the hot water storage unit 20 is supplied to the hot water supply tap 8 via the auxiliary heat source machine 40 and is supplied with hot water as indicated by the arrow HW from the hot water supply tap 8.

[0021] The hot water storage unit 20 has a control unit 29 (control means) for controlling the hot water storage operation of driving the pump 22 to circulate hot water between the hot water storage tank 21 and the main heat source machine 10 and storing the hot water heated by the main heat source machine 10 from the upper part of the hot water storage tank 21 into the hot water storage tank 21. This control unit 29 adjusts the mixing ratio in the mixing valve 28 to discharge hot water so that the temperature detected by the hot water discharge temperature sensor 27c becomes, for example, a preset hot water supply set temperature or a predetermined temperature based on the hot water storage tank hot water discharge temperature, the water supply temperature, and the hot water discharge flow rate. The predetermined temperature is set so that the auxiliary heat source machine 40 can heat the hot water supplied from the hot water storage unit 20 to the hot water supply set temperature for hot water supply.

[0022] For example, an operating terminal 30 is installed on the wall of an indoor area such as a kitchen, which is equipped with a display unit that shows information related to hot water supply and hot water storage operation, and is used to set the hot water temperature and fill the bathtub with hot water. This operating terminal 30 is connected to the auxiliary heat source unit 40 in a communicative manner and is configured to supply hot water at the hot water temperature set on the operating terminal 30 to the hot water tap 8. In addition, the operating terminal 30 is connected to the control unit 29 of the hot water storage unit 20 in a communicative manner via the auxiliary heat source unit 40, and can perform setting operations related to hot water storage operation.

[0023] As shown in Figure 2, the auxiliary heat source unit 40 includes a fuel gas supply unit 43, a blower fan 44 for supplying combustion air, a hot water burner 45 and a bath burner 46 for burning the fuel gas, a hot water heat exchanger 47 for heating hot water using the heat of the high-temperature combustion gas generated by combustion, and a bath heat exchanger 48 for heating the hot water in the bathtub 3. In the hot water supply passage 49 that supplies hot water from the hot water storage unit 20 to the hot water heat exchanger 47 as indicated by arrow W, a hot water temperature sensor 49a for detecting the temperature of the hot water and a hot water flow rate sensor 49b for detecting the flow rate of hot water supplied to the hot water heat exchanger 47 are provided. Upstream of the hot water temperature sensor 49a and the hot water flow rate sensor 49b, a distribution valve 50 with an adjustable distribution ratio is provided.

[0024] The auxiliary heat source unit 40 has an auxiliary heat source unit control unit 51 in order to control the distribution ratio of the distribution valve 50 based on the temperature detected by the hot water temperature sensor 49a, and to control the combustion of the hot water burner 45. The auxiliary heat source unit control unit 51 burns the hot water burner 45 and heats the hot water in the hot water heat exchanger 47 according to the temperature detected by the hot water temperature sensor 49a. This heated hot water is supplied to the auxiliary heat source unit outlet passage 52, and is mixed with unheated hot water from a bypass passage 53 that branches off from the hot water supply passage 49 and is connected to the auxiliary heat source unit outlet passage 52 in the distribution valve 50, and the temperature is adjusted.

[0025] When the hot water supply destination is the hot water tap 8, hot water adjusted to the hot water set temperature is supplied to the hot water tap 8. When the hot water supply destination is the bathtub 3, hot water adjusted to the bath set temperature is poured into the bathtub 3 via the pouring passage 54 branched from the auxiliary heat source unit's hot water outlet passage 52. Pouring is performed when the pouring valve 55 (pouring means) that opens and closes the pouring passage 54 is open. The flow rate of hot water poured into the bathtub 3 is detected by a pouring flow rate sensor 56 located upstream of the pouring valve 55. The auxiliary heat source unit control unit 51 calculates the amount of hot water poured into the bathtub 3 based on this pouring flow rate and the time the pouring valve 55 is open (pouring time), and pours a predetermined amount of hot water to reach a preset water level.

[0026] A reheating passage 58 equipped with a bath pump 57 is connected to the bath heat exchanger 48 to circulate the hot water from the bathtub 3. The auxiliary heat source control unit 51 controls the reheating operation by driving the bath pump 57 and burning it with the bath burner 46, thereby heating the hot water from the bathtub 3 that has been circulated through the reheating passage 58 in the bath heat exchanger 48 and returning it to the bathtub 3.

[0027] The hot water supply passage 54 is connected to the reheating passage 58 via the bath pump 57. When hot water is supplied, the hot water supply valve 55 is opened, and hot water adjusted to the bath set temperature by the hot water storage unit 20 or the auxiliary heat source unit 40 is supplied to the bathtub 3 from the hot water supply passage 54 via the reheating passage 58. The open / closed state of the hot water supply valve 55, the amount of heat released by the auxiliary heat source unit 40, etc., are transmitted from the auxiliary heat source unit control unit 51 to the control unit 29.

[0028] The hot water output heat quantity detection means is comprised of a hot water output flow sensor 27a and a hot water output temperature sensor 27c that detect the amount of heat output from the hot water storage unit 20, an auxiliary heat source unit control unit 51 that transmits the amount of heat that the auxiliary heat source unit 40 heats and outputs, and a control unit 29 that acquires the amount of heat output from the hot water storage unit 20 and the amount of heat that the auxiliary heat source unit 40 heats and outputs. The control unit 29 has a function to learn and store the time of hot water output from the hot water storage unit 20, the amount of heat output, and the amount of heat that the auxiliary heat source unit 40 heats and outputs as hot water output records.

[0029] The amount of hot water heat dispensed from the hot water storage unit 20 when the hot water supply valve 55 is open, and the amount of heat heated and dispensed by the auxiliary heat source unit 40 when the hot water supply valve 55 is open, are each learned and stored by the control unit 29 as hot water supply records, along with the time (date and time) when the hot water supply was performed. On the other hand, the amount of hot water heat dispensed from the hot water storage unit 20 when the hot water supply valve 55 is closed, and the amount of heat heated and dispensed by the auxiliary heat source unit 40 when the hot water supply valve 55 is closed, are each learned and stored by the control unit 29 as hot water supply records, along with the time (date and time) when the hot water supply was performed. The hot water supply records include these hot water supply records and hot water supply records.

[0030] The control unit 29 predicts the future amount of hot water to be dispensed as the required amount of heat for each time period divided into predetermined time intervals, based on past hot water output records that it has learned and stored. It then controls the hot water storage operation by summing up the required amounts of heat for multiple consecutive time periods, which constitute a predetermined period, so that the storage of the required amount of hot water is completed before that time period. The predetermined period is set to span four time periods, for example, but is not limited to this.

[0031] When predicting the required heat, the predicted heat amount for hot water supply is predicted for each time period based on the actual hot water supply data, and the predicted heat amount for hot water supply is predicted for each time period based on the actual hot water supply data. The sum of the predicted heat amount for hot water supply and the predicted heat amount for hot water supply for the same time period is considered the required heat for the corresponding time period. The predicted heat amount for hot water supply is the average value of the actual hot water supply data for each time period over a predetermined reference period (for example, the past 14 days from the time period immediately preceding the time period to which the current time belongs). Similarly, the predicted heat amount for hot water supply is the average value of the actual hot water supply data for each time period over the same reference period. This prediction of the required heat is performed each time the current time transitions to the next time period.

[0032] The required heat quantity is a prediction based on actual hot water output, so the prediction may not always be accurate. For example, if the hot water supply prediction is inaccurate and the stored predicted heat quantity is not used, it results in wasted energy compared to storing the predicted heat quantity and then supplying the hot water. Also, if the hot water is heated using the auxiliary heat source unit 40 without storing the predicted heat quantity and then supplied, the energy consumption will increase compared to storing the predicted heat quantity and then supplying the hot water, because the energy efficiency of the auxiliary heat source unit 40 is lower than that of the main heat source unit 10.

[0033] These wastes or increases are considered to be energy losses when the predicted heat amount for hot water injection is stored by the main heat source unit 10 and then injected. Therefore, in order to reduce this energy loss, a decision is made as to whether or not to include the predicted heat amount for hot water injection in the required heat amount when predicting the required heat amount. This prediction of the required heat amount will be explained based on the flowchart in Figure 3 and Figure 4. In the figures, Si (i=1,2,···) represents a step.

[0034] When the prediction of required heat quantity begins, the hot water output data (hot water pouring data and hot water supply data) is first obtained in S1, and the process proceeds to S2. The hot water output data includes hot water pouring data (hot water pouring heat quantity, hot water pouring time) for each time period within a predetermined reference period of length, starting from the time period immediately preceding the current time period, and hot water supply data other than hot water pouring data (hot water supply heat quantity, hot water supply time) for each time period within the same reference period. The period for predicting required heat quantity is, for example, 18 hours from the current time, but is not limited to this; it may be, for example, 12 hours or 24 hours.

[0035] In S2, the predicted heat quantity for hot water injection and hot water supply for each time period is predicted based on the hot water output data, and the process proceeds to S3. The predicted heat quantity for hot water injection is the average value of the heat quantity for hot water injection for each time period during the reference period, and the predicted heat quantity for hot water supply is the average value of the heat quantity for hot water supply for each time period during the reference period. The sum of the predicted heat quantity for hot water injection and the predicted heat quantity for hot water supply for the same time period is the required heat quantity for that time period. Figure 4 shows an example of the required heat quantity predicted when the current time is 1 o'clock. The required heat quantity is predicted from 1 o'clock to 19:00, with hot water supply predicted for the morning and noon periods and from 17:00 to 19:00, and hot water injection predicted for the 18:00 period. The predicted heat quantity for hot water injection in the 18:00 period corresponds to the predicted heat quantity C for one hot water injection.

[0036] In S3 of Figure 3, the rate of hot water application p for the reference period is calculated, and the process proceeds to S4. The rate of hot water application p is calculated by dividing the number of days on which hot water application was performed within this reference period by the number of days in this reference period. If hot water application is performed every day, p=1, and the rate of hot water application p will be a value within the range of 0 to 1. Note that even if hot water is applied multiple times in a single day, the number of days on which hot water application was performed is counted as 1.

[0037] In S4, the hot water utilization rate β for the reference period is calculated, and the process proceeds to S5. At this time, the hot water utilization rate β is calculated as the ratio of the average daily hot water heat supply during the reference period to the predicted heat supply C for one hot water pour ((average daily hot water heat supply) / (predicted heat supply C for one hot water pour)).

[0038] In S5, based on the hot water injection rate p, the hot water utilization rate β, the predicted heat amount C for one injection, and the energy efficiency H of the main heat source unit 10, the expected energy loss (expected hot water storage loss L1) when the predicted heat amount C for one injection is stored is calculated, and the process proceeds to S6. The energy efficiency H of the main heat source unit 10 is generally calculated as the product of a coefficient of 0.369 and the COP (coefficient of performance) of the main heat source unit 10.

[0039] The expected value is the sum of the products of the values ​​(random variables) obtained from possible events and the probability of those events occurring. The probability of performing a hot water pour is the pouring rate p based on past pouring records. If we assume that the energy loss is zero when the predicted heat amount C for one pour is stored and poured, the expected storage loss L1 is expressed as the energy loss when the hot water is not stored and poured, as shown in equation (1) below. L1=p·0+(1-p)·C·(1-β) / H···(1) This equation (1) represents the heat loss due to the heat released when hot water is stored but not used.

[0040] In S6, based on the hot water injection rate p, the hot water utilization rate β, the predicted heat quantity C for one injection, the energy efficiency H of the main heat source unit 10, and the energy efficiency G of the auxiliary heat source unit 40, the expected energy loss (expected hot water loss L2) when the predicted heat quantity C for one injection is not stored is calculated, and the process proceeds to S7. The energy efficiency G is determined by the specifications of the auxiliary heat source unit 40 and is often a value less than 1, for example, around 0.8 to 0.95. If the predicted heat quantity C for one injection is not stored and no injection is performed, the energy loss is zero. Therefore, the expected hot water loss L2 is the energy loss when hot water is injected without storage, and is expressed as shown in equation (2) below. L2=p·C·(1 / G-1 / H)+(1-p)·0 ···(2) Equation (2) represents the energy consumption when the main heat source unit 10 stores the predicted heat amount C for one pour compared to the energy consumption when the auxiliary heat source unit 40 supplies the predicted heat amount C for one pour, that is, the loss due to the difference in energy efficiency between the main heat source unit 10 and the auxiliary heat source unit 40.

[0041] In S7, it is determined whether the expected hot water storage loss L1 is less than or equal to the expected hot water supply loss L2. This is determined by comparing equations (1) and (2) to see if L1 ≤ L2 holds true. Alternatively, the following equation (3), derived from equations (1) and (2), can be used as the criterion, and S5, S6, and S7 can be used together to determine whether this criterion holds. p≧(1-β)·G / (H-β·G) ···(3)

[0042] If the determination in S7 is Yes (if the determination formula (3) is true), proceed to S8. In S8, since the expected loss is smaller if the predicted heat amount C for one pour is stored, the predicted heat amount C is included in the required heat amount during the time period in which the predicted heat amount C is present. The sum of the predicted heat amount C for one pour and the predicted heat supply during this time period is calculated as the required heat amount, and the prediction of the required heat amount is completed.

[0043] On the other hand, if the determination in S7 is No (if the determination formula (3) is not true), the process proceeds to S9. In S9, since not storing the predicted heat quantity C for one pour of hot water results in a smaller expected loss, even during the time period when there is a predicted heat quantity C for one pour of hot water, the prediction of the required heat quantity is terminated, with only the predicted heat quantity for hot water supply being considered as the required heat quantity.

[0044] In this way, the required heat quantity is predicted in such a way that the expected value of energy loss when the hot water supply does not occur as predicted is minimized. This reduces energy loss and lowers the running costs of the hot water storage and supply system.

[0045] The operation and effects of the above-described hot water storage and supply system 1 will be explained. The hot water storage and supply system 1 determines whether or not to store the predicted heat amount C for one hot water supply, based on the expected energy loss if the predicted heat amount for hot water supply is not stored and hot water supply is not performed (expected storage loss L1), and the expected energy loss if the predicted heat amount for hot water supply is performed without storing it (expected hot water supply loss L2). Since the decision is made according to the expected energy loss, for example, by selecting the option with the smaller expected energy loss, the energy loss of the hot water storage and supply system can be reduced.

[0046] Furthermore, if the expected hot water storage loss L1 is less than or equal to the expected hot water supply loss L2, the required heat amount including the predicted hot water supply heat amount C, i.e., the predicted hot water supply heat amount C and the predicted hot water supply heat amount, is stored. If the expected hot water storage loss L1 is greater than the expected hot water supply loss L2, the required heat amount excluding the predicted hot water supply heat amount C, i.e., the predicted hot water supply heat amount, is stored. Therefore, since the option with the smaller expected energy loss for hot water supply is selected, the energy loss of the hot water storage and hot water supply system can be reduced.

[0047] The expected hot water storage loss L1 and the expected hot water supply loss L2 are calculated using the hot water supply rate p and the hot water utilization rate β, based on the actual hot water output during the reference period. By using the expected hot water storage loss L1 and the expected hot water supply loss L2, which reflect the actual usage patterns, it is possible to determine whether or not to store the predicted heat amount C for hot water supply, thereby reducing the energy loss of the hot water storage and supply system 1.

[0048] Furthermore, those skilled in the art can implement the present invention in various forms with modifications to the above embodiments without departing from the spirit of the invention, and the present invention encompasses such modifications. [Explanation of Symbols]

[0049] 1: Hot water storage and supply system 3: Bathtub 8: Hot water tap 10: Main heat source machine 20: Hot water storage unit 21: Hot water storage tank 21a~21d: Hot water storage temperature sensor 22: Pump 23: Passage to the heat source unit 24: Heat source return passage 24a: Return branch passage 24b: Return temperature sensor 25: Switching valve 26:Water supply passage 26a: Water supply branching passage 26b: Water supply temperature sensor 27: Hot spring access passage 27a: Hot water flow sensor 27b: Hot water storage tank outlet temperature sensor 27c: Hot water temperature sensor 28: Mixing valve 29: Control unit (control means) 30: Operating terminal 40:Auxiliary heat source machine 40a: Water inlet 40b: Hot water outlet 41:Hot water passage 42: Hot water supply passage 43: Fuel Gas Supply Department 44: Blower fan 45: Hot water burner 46: Bath Burner 47: Hot water heat exchanger 48: Bath heat exchanger 49:Hot water supply passage 49a: Hot water temperature sensor 49b: Hot and cold water flow sensor 50: Distribution valve 51: Auxiliary heat source unit control 52: Auxiliary heat source unit hot water outlet passage 53: Bypass passage 54: Pouring channel 55:Pouring valve (pouring means) 56: Pouring flow sensor 57: Bath pump 58: Reheating passage

Claims

1. A hot water storage and supply system comprising: a hot water storage tank for storing hot water; a main heat source unit for heating the hot water in the hot water storage tank; a hot water outlet passage for dispensing hot water from the hot water storage tank; an auxiliary heat source unit to which the hot water dispensed from the hot water outlet passage is supplied; a hot water dispensing means for dispensing hot water from the auxiliary heat source unit via a dispensing passage connected to a bathtub; a hot water outlet heat quantity detection means for detecting the amount of hot water heat dispensed via the auxiliary heat source unit; and a control means for predicting the required amount of heat for each time period divided into predetermined time intervals based on the amount of hot water heat dispensed detected by the hot water outlet heat quantity detection means and past hot water dispensing records including the time of dispensing, and controlling the system to store the sum of the required amounts of heat for a predetermined number of time periods, The hot water storage and supply system is characterized in that the control means is configured to determine whether or not to include the predicted hot water heat amount in the required heat amount when adding the predicted hot water heat amount and the predicted hot water supply heat amount for each time period, which are predicted based on the hot water supply performance by the hot water supply means and the hot water supply performance other than hot water supply included in the hot water output performance, based on the expected value of the hot water storage loss, which is the expected value of the energy loss when the predicted hot water heat amount is stored by the main heat source and hot water supply is not performed, and the expected value of the hot water supply loss, which is the expected value of the energy loss when the predicted hot water heat amount is supplied by the auxiliary heat source without storing the hot water.

2. The hot water supply system according to claim 1, characterized in that the control means determines to include the predicted heat amount for hot water supply in the required heat amount when the expected value of hot water storage loss is less than or equal to the expected value of hot water supply loss, and determines not to include the predicted heat amount for hot water supply in the required heat amount when the expected value of hot water storage loss is greater than the expected value of hot water supply loss.

3. The hot water storage and hot water supply system according to claim 1 or 2, characterized in that the expected hot water storage loss and the expected hot water supply loss are calculated, respectively, by using the hot water supply rate, which is the ratio of the average daily hot water supply heat amount during the reference period to the predicted hot water supply heat amount, obtained by dividing the number of days on which hot water was supplied during a reference period of a predetermined length by the number of days in the reference period, based on the actual hot water supply performance, and the hot water supply utilization rate, which is the ratio of the average daily hot water supply heat amount during the reference period to the predicted hot water supply heat amount.

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