Flow rate estimation device, flow rate estimation method and program

Abstract

A method is provided for estimating the flow rate of hot water supplied from a hot water supply system to a load. [Solution] The flow rate estimation device is a flow rate estimation device that estimates the flow rate of hot water supplied from a hot water supply system that has a heat source machine and a hot water storage tank that stores hot water produced by the heat source machine, and is equipped with a flow rate estimation unit that estimates the amount of hot water inflow into the hot water storage tank from a first temperature that is the temperature of the water flowing into the heat source machine, a second temperature that is the temperature of the hot water supplied from the heat source machine to the hot water storage tank, and the heating capacity of the heat source machine calculated based on the first temperature, the second temperature, and the outside air temperature, and estimates the flow rate of hot water supplied from the hot water storage tank from the inflow rate and changes in the amount of hot water stored in the hot water storage tank, and a correction unit that calculates a correction function that converts the estimated value to an actual measured value based on the estimated value of the hot water flow rate estimated by the flow rate estimation unit and the actual measured value of the hot water flow rate corresponding to the estimated value, and corrects the estimated value based on the correction function.

Description

[Technical Field]

[0001] The present disclosure relates to a flow rate estimation device, a flow rate estimation method, and a program. [Background technology]

[0002] Hot water supply systems are used to supply hot water to kitchens and bathing facilities in restaurants, hotels, schools, hospitals, welfare facilities, and other facilities. In a hot water supply system, a water heater heats water and stores the heated hot water in a hot water storage tank. The hot water stored in the hot water storage tank is then supplied to kitchens, bathing facilities, and other facilities. For efficient operation of a hot water supply system, a method has been proposed for predicting future hot water demand and creating a hot water storage plan that can meet the daily demand forecast while avoiding hot water shortages (e.g., Patent Document 1). Creating such a hot water storage plan requires accurate prediction of hot water demand. For example, if a hot water supply system is equipped with a sensor that measures the flow rate of hot water supplied from the hot water storage tank to the demand-side facility, it is possible to record the daily flow rate measured by this sensor and perform demand predictions by learning from the recorded data, etc. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-181852 Summary of the Invention [Problem to be solved by the invention]

[0004] However, some hot water supply systems do not have a permanent sensor installed to measure the amount of hot water supplied from the hot water storage tank. In such hot water supply systems, it is not possible to perform demand forecasting based on the amount of hot water measured by the sensor. In hot water supply systems that do not have a permanent sensor installed to measure the amount of hot water, a method for estimating the amount of hot water supplied to a facility from the hot water supply system is needed.

[0005] The present disclosure provides a flow rate estimation device, a flow rate estimation method, and a program that can solve the above-mentioned problems. [Means for solving the problem]

[0006] The flow rate estimation device disclosed herein is a flow rate estimation device that estimates the flow rate of hot water supplied from a hot water supply system that includes a heat source machine and a hot water storage tank that stores hot water produced by the heat source machine, and includes a flow rate estimation unit that estimates the amount of hot water that flows into the hot water storage tank from a first temperature that is the temperature of water flowing into the heat source machine, a second temperature that is the temperature of hot water supplied from the heat source machine to the hot water storage tank, and a heating capacity of the heat source machine calculated based on the first temperature, the second temperature, and an outside air temperature, and estimates the flow rate of hot water supplied from the hot water storage tank from the inflow rate and changes in the amount of hot water stored in the hot water storage tank; and the flow rate of hot water estimated by the flow rate estimation unit. and a correction unit that acquires a plurality of data sets of estimated values ​​and actual measured values ​​of the hot and cold water flow rates corresponding to the estimated values, plots the plurality of data sets on a graph using the estimated values ​​and the actual measured values ​​as coordinate axes based on the acquired plurality of data sets, inverts the points indicated by the plotted estimated values ​​and the actual measured values ​​to positions that are symmetrical about a line on the graph where the estimated values ​​and the actual measured values ​​are equal, calculates an approximation function that approximates the distribution shape of the points after the inversion as a correction function that converts the estimated values ​​to the actual measured values, and corrects the estimated values ​​estimated by the flow rate estimation unit based on the correction function.

[0007] The flow rate estimation method of the present disclosure is a flow rate estimation method for estimating the flow rate of hot water supplied from a hot water supply system including a heat source machine and a hot water storage tank for storing hot water produced by the heat source machine, the method comprising the steps of: estimating the amount of hot water inflowing into the hot water storage tank from a first temperature which is the temperature of water flowing into the heat source machine; a second temperature which is the temperature of hot water supplied from the heat source machine to the hot water storage tank; and the heating capacity of the heat source machine calculated based on the first temperature, the second temperature, and an outside air temperature; estimating the flow rate of hot water supplied from the hot water storage tank from the inflow rate and changes in the amount of hot water stored in the hot water storage tank; and The method includes a step of acquiring multiple data sets of estimated flow rates and actual measured values ​​of the hot and cold water flow rates corresponding to the estimated values, plotting the multiple data sets on a graph based on the acquired multiple data sets with the estimated values ​​and the actual measured values ​​as coordinate axes, inverting the points indicated by the plotted estimated values ​​and the actual measured values ​​to positions that are linearly symmetrical about the line on the graph where the estimated values ​​and the actual measured values ​​are equal, calculating an approximation function that approximates the distribution shape of the points after inversion as a correction function that converts the estimated values ​​to the actual measured values, and correcting the estimated values ​​estimated in the estimating step based on the correction function.

[0008] The program of the present disclosure is also a process for estimating the flow rate of hot water supplied from a hot water supply system including a heat source machine and a hot water storage tank for storing hot water produced by the heat source machine, the process including the steps of estimating the amount of hot water inflowing into the hot water storage tank from a first temperature which is the temperature of water flowing into the heat source machine, a second temperature which is the temperature of hot water supplied from the heat source machine to the hot water storage tank, and the heating capacity of the heat source machine calculated based on the first temperature, the second temperature, and an outside air temperature, and estimating the flow rate of hot water supplied from the hot water storage tank from the inflow rate and changes in the amount of hot water stored in the hot water storage tank; and The method includes the steps of: acquiring multiple data sets of estimated values ​​and actual measured values ​​of the hot and cold water flow rate corresponding to the estimated values; plotting the multiple data sets on a graph based on the acquired multiple data sets, with the estimated values ​​and the actual measured values ​​as coordinate axes; inverting the points indicated by the plotted estimated values ​​and the actual measured values ​​to positions that are symmetrical about the line on the graph where the estimated values ​​and the actual measured values ​​are equal; calculating an approximation function that approximates the distribution shape of the points after inversion as a correction function that converts the estimated values ​​to the actual measured values; and correcting the estimated values ​​estimated in the estimating step based on the correction function. [Effects of the Invention]

[0009] According to the above-described flow rate estimation device, flow rate estimation method, and program, it is possible to estimate the flow rate of hot water or water supplied from a hot water supply system to a load. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a diagram illustrating an example of a hot water supply system according to an embodiment. [Figure 2] 1 is a block diagram illustrating an example of a flow rate estimation device according to an embodiment. [Figure 3] 1A and 1B are diagrams illustrating a flow rate estimation method according to an embodiment. [Figure 4] FIG. 4 is a diagram showing an example of a characteristics table of a heat source machine according to the embodiment. [Figure 5]10A and 10B are diagrams illustrating a flow rate correction process according to an embodiment. [Figure 6] 10 is a flowchart illustrating an example of a flow rate estimation process according to the embodiment. [Figure 7] FIG. 1 is a diagram illustrating an example of a hardware configuration of a flow rate estimation device according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] <Embodiment> The flow rate estimation method of the present disclosure will be described below with reference to the drawings. (System Configuration) FIG. 1 is a diagram showing an example of a hot water supply system according to each embodiment. As shown in the figure, the hot water supply system 1 includes a heat source unit 2, a hot water storage tank 3, a facility 4, an edge server 100B, and a cloud server 100C. The heat source unit 2 and the hot water storage tank 3 are connected by piping 9B, and the hot water storage tank 3 and the facility 4 are connected by piping 9C. Water is supplied to the heat source unit 2 through piping 9A. The heat source unit 2 includes a refrigerant circuit including, for example, a compressor, a condenser, an expansion valve, and an evaporator. The heat source unit 2 heats the water and generates hot water by heat exchange in the condenser. A temperature sensor 5 is provided on the inlet side of the heat source unit 2 to measure the temperature of the water supply, and a temperature sensor 6 is provided on the outlet side to measure the temperature of the water after heating, i.e., the temperature of the water supplied to the hot water storage tank 3. Although only one heat source unit 2 is shown in FIG. 1, multiple heat source units 2 may be provided. One or more heat source units 2 send the generated hot water to the hot water storage tank 3 through piping 9B. The hot water storage tank 3 stores the delivered hot water. The hot water storage tank 3 is provided with a water level sensor 7 that measures the amount of stored hot water. The heat source unit 2 is provided with a controller 100A, which controls the heat source unit 2 so that the amount of stored hot water measured by the water level sensor 7 reaches a target value. Then, the hot water storage tank 3 is supplied to the facility 4 through piping 9C in an amount that corresponds to the demand of the facility 4. The hot water supply system 1 is also provided with a sensor 8 that measures the outside air temperature.

[0012] The controller 100A, the edge server 100B, and the cloud server 100C are computers equipped with processors. The controller 100A and the edge server 100B, and the edge server 100B and the cloud server 100C are communicatively connected. The cloud server 100C is a server located outside the facility where the heat source unit 2 and the hot water storage tank 3 are installed, for example, in a data center. The cloud server 100C performs tasks such as predicting hot water demand and creating a hot water storage plan that determines the amount of hot water to be stored in the hot water storage tank 3 for each predetermined time period. Methods for predicting demand and creating a hot water storage plan are disclosed in, for example, Patent Document 1. The edge server 100B is located in the facility where the heat source unit 2 and the like are installed, and acts as an intermediary between the controller 100A and the cloud server 100C by transmitting information about the heat source unit 2 and the hot water storage tank 3 (such as measurements from various sensors) to the cloud server 100C and receiving the hot water storage plan from the cloud server 100C.

[0013] Here, a flow rate sensor 99 for measuring the amount of hot water supplied to the facility 4 is not permanently installed on the pipe 9C. For example, it is assumed that the flow rate sensor 99 is temporarily installed when the hot water supply system 1 is installed or during maintenance, and then removed during operation. For this reason, the flow rate sensor 99 is indicated by a dashed line in FIG. 1. In this embodiment, the measurement values ​​of sensors 5 to 8 are acquired and the flow rate of hot water supplied to the facility 4 through the pipe 9C is estimated. This estimated value is then corrected using a correction function g, which will be described later, to improve the accuracy of the flow rate estimation. The cloud server 100C then predicts hot water demand based on the corrected estimated flow rate and calculates a target value for the hot water storage amount (hot water storage plan) corresponding to the demand prediction. The controller 100A then operates the heat source unit 2 based on the hot water storage plan. The temporary installation of the flow rate sensor 99 is assumed because the correction function g is derived using data accumulated with the flow rate sensor 99 installed. Of course, the flow rate estimation method of this embodiment can be applied even if the flow rate sensor 99 is permanently installed. Furthermore, even if the flow rate sensor 99 is not temporarily installed, a facility with similar specifications and environments, such as the installation area, tank type, tank volume, and number of heat source devices, may be selected from facilities that have already introduced a system similar to the hot water supply system 1 and are (temporarily) equipped with a flow meter, and the correction function g derived in the selected facility may be reused in the hot water supply system 1. In this case, the flow rate sensor 99 is not necessary.

[0014] (Configuration of flow rate estimation device) Next, with reference to FIG. 2, a flow rate estimation device for estimating the flow rate of hot and cold water will be described. FIG. 2 is a block diagram showing an example of a flow rate estimation device according to each embodiment. The illustrated flow rate estimation device 10 is implemented in any one of a controller 100A, an edge server 100B, or a cloud server 100C. As an example, FIG. 1 shows a configuration in which the cloud server 100C is equipped with the flow rate estimation device 10. As shown in FIG. 2, the flow rate estimation device 10 includes a data acquisition unit 11, a flow rate estimation unit 12, a correction unit 13, an output unit 14, and a storage unit 15. The data acquisition unit 11 acquires various information necessary for estimating the flow rate of hot and cold water. For example, the data acquisition unit 11 acquires the measurement values ​​measured by the various sensors 5 to 8 and the measurement value measured by the flow rate sensor 99. The flow rate estimation unit 12 estimates the flow rate of hot water supplied from the hot water storage tank 3 to the facility 4 based on the measured values ​​measured by the sensors 5-8 and the like. The correction unit 13 calculates a correction function g based on the relationship between the actual measurement value and the estimated value of the outflow amount from the hot water storage tank 3, and corrects the estimated value of the outflow amount using the correction function g so as to approach the actual measurement value. The output unit 14 outputs or transmits to another device the flow rate estimated by the flow rate estimation unit 12 and corrected by the correction unit 13. For example, the output unit 14 outputs the estimated value of the hot and cold water flow rate to a hot and cold water demand prediction unit (not shown) provided in the cloud server 100C. The storage unit 15 stores the data acquired by the data acquisition unit 11 and the like.

[0015] (Flow rate estimation method) Next, a method for estimating the flow rate of hot water supplied from the hot water storage tank 3 to the facility 4 by the flow rate estimating unit 12 will be described with reference to Figs. 3 and 4. Fig. 3 is a diagram for explaining the flow rate estimating method according to the embodiment. In Fig. 3, a plurality of heat source machines 2 (N H The figure shows a schematic diagram of the hot water supply system. The amount of hot water flowing out of the hot water storage tank 3 can be calculated as the difference between the "amount flowing into the tank" and the "change in the amount of hot water stored" as shown in the following formula (1). Outflow from hot water storage tank = inflow to hot water storage tank - increase in hot water storage volume (1) The change in the amount of hot water stored, which is the second term on the right-hand side of equation (1), can be measured by the water level sensor 7. The issue then becomes how to estimate the amount of inflow into the hot water storage tank 3. Here, if the outflow amount is represented as Vtank,out(l), the inflow amount as Vtank,in(l), and the change in the amount of hot water stored as ΔVtank(l), equation (1) can be expressed as the following equation (1'). Vtank,out(l)=Vtank,in(l)-ΔVtank···(1´) Here, ΔVtank is the change in the amount of hot water stored in a short time Δt as shown in the following equation (2). ΔVtank=Vtank(t)-Vtank(t-Δt)...(2) The relationship between the volume V (l) and the flow rate F (l / min) is as follows: V(l)=F(l / min)×Δt(min)...(3) It can be expressed as:

[0016] It is known that the following formulas (4) and (5) hold true as thermodynamic formulas for the hot water supply system 1. Q(kJ / s)=Cp(kJ / kg・℃)×G(l / s)×ΔT H (℃) (4) ΔT H =T H,i,out -T H,i,in ···(5) where T H,i,out is the hot water temperature at the outlet of the heat source unit 2 (measured value of temperature sensor 6), T H,i,in is the water supply temperature on the inlet side of the heat source unit 2 (measured value by temperature sensor 5), Cp is the low-pressure specific heat of water (4.187 (kJ / kg·°C)), and G is the amount of hot water flowing out of the heat source unit 2, i.e., the amount of inflow Vtank,in into the hot water storage tank 3 in question. Q is the heating capacity of the heat source unit 2, and is a value determined from the water supply temperature on the inlet side of the heat source unit 2, the hot water temperature on the outlet side, and the outside air temperature. Specifically, a characteristic table relating to heating capacity, as shown in Figure 4, is generally provided as specification data for the heat source unit 2. In the characteristic table, the inlet temperature (measured value by temperature sensor 5), the outlet temperature (measured value by temperature sensor 6), the outside air temperature (measured value by temperature sensor 8), and the heating capacity Q are associated. The value of the heating capacity Q is determined from the characteristic table in Figure 4 and the measured values ​​of temperature sensors 5 to 6 and 8, and Q, constants Cp and ΔT H (ΔT H This can also be calculated from the measured values ​​of temperature sensors 5 and 6 using the above equation (5). The hot water outflow volume G (= Vtank,in) can be calculated using equation (4), and the outflow volume Vtank,out from the hot water storage tank 3 can be calculated using equation (1').

[0017] N H The outflow volume from the ith heat source unit 2 among the heat source units 2 is GH,i , the heating capacity of the i-th heat source unit 2 is Q H,i , the inlet water temperature is T H,i,in , the outlet supply water temperature is T H,i,out and by transforming equation (4), we obtain the following equation (6). G H,i =Q H,i ÷(Cp×(T H,i,out -T H,i,in ))···(6) Therefore, the inflow rate Vtank,in into the hot water tank 3 per unit time Δt can be calculated by the following equation (7).

[0018]

number

[0019] The flow rate estimation unit 12 estimates Vtank,out(l) using equations (7) and (1'), and estimates the flow rate (l / s) of hot and cold water flowing through the pipe 9C using equation (3) from the estimated outflow rate (l). In this way, the flow rate of hot and cold water can be estimated, but there is a possibility that the error from the actual measured value will be large. Therefore, in this embodiment, a correction is made to bring the estimated amount of hot water used closer to the actual measured value.

[0020] (Correction method) Next, the flow rate correction process according to this embodiment will be described with reference to FIG. The vertical axis of the scatter diagram in Figure 5 is the estimated value of the flow rate (l / s) estimated by the flow rate estimation unit 12 using the above method, and the horizontal axis is the actual measured value (l / s) of the hot water flow rate supplied from the hot water storage tank 3 to the facility 4, measured by the flow rate sensor 99. Each point on the scatter diagram in Figure 5 indicates the relationship between the estimated value of the flow rate and the actual measured value at a certain point in time. The data acquisition unit 11 acquires the measured values ​​of sensors 5 to 8 as well as sensor 99, and records the actual measured value of the hot water flow rate in memory unit 15 in association with the time. The flow rate estimation unit 12 calculates an estimated value of the hot water flow rate based on the measured values ​​of sensors 5 to 8 using the method described with reference to Figures 3 and 4, and records the estimated value in memory unit 15 in association with the time. The correction unit 13 calculates the correction function g using the following procedure. (Step 1) The correction unit 13 plots the data set of estimated and measured hot and cold water flow rates at the same time recorded in the memory unit 15 on a graph with the estimated and measured flow rates as coordinate axes, to create a scatter plot as shown in Figure 5. As mentioned above, the vertical axis (y-axis) of Figure 5 is the estimated flow rate, and the horizontal axis (x-axis) is the measured flow rate. If the estimated and measured values ​​are equal, the data set will be plotted on the line Q where y = x. In other words, if the accuracy of the flow rate estimated by the flow rate estimation unit 12 is high, the data set of measured and estimated values ​​will be plotted near the line Q. In the case of the data set of the circle Pi shown in Figure 5, the estimated value is slightly larger than the measured value. The light-black circle represented by P1 in Figure 5 is an example of a data set of measured and estimated values. Each light-black circle will be written as Pi (i = 1 to n). (Step 2) The correction unit 13 inverts each dot Pi to a position symmetrical to the line Q. This can be done by swapping the y and x values ​​of each dot Pi. Each point obtained in this way is referred to as Pi'. For example, the point obtained by inverting the light-black dot P1 to a position symmetrical to the line Q is the white dot P1'. (Step 3) The correction unit 13 obtains an approximation formula g that approximates the distribution of the point set Pi' (i = 1 to n) obtained in step 2. This g is used as a correction function. The correction unit 13 obtains a curve that approximates the distribution shape of the inverted point set Pi' by curve fitting, and calculates a correction function g that indicates the relationship between the estimated value after inversion and the actual measured value after inversion. Here, considering the meaning of the correction function g, the correction function g is the inverse function of the function y = f(x) that indicates the relationship between the actual measured value x (actual measured value before inversion) of the hot and cold water flow rate and the estimated value y (estimated value before inversion), that is, the function x = f that obtains the actual measured value from the estimated value -1(y). In other words, when a new estimated value x is obtained, by converting it using the correction function g as y = g(x), this y becomes a corrected estimated value that approximates the actual measured value. For example, triangular points such as P2 in FIG. 5 are points that represent a data set of the estimated value of flow rate estimated by the flow rate estimation unit 12 and the actual measured value (measured with the flow sensor 99 installed). Diamond-shaped points such as P2' are points that represent a data set of the corrected estimated value of flow rate and the actual measured value obtained by inputting the estimated value x into the correction function g. As shown in the figure, the corrected diamond-shaped points are plotted on or near the line Q. In other words, it can be seen that correction using the correction function g makes it possible to estimate a flow rate that is closer to the actual measured value.

[0021] In addition, in calculating the correction function g, the circle points Pi are not inverted to a line-symmetric position with respect to the straight line Q, but a curve that approximates the distribution shape of the circle points Pi is calculated to calculate the function f, and the inverse function f of the function f is calculated. -1 By calculating f, it is possible to derive a function with the same meaning as the correction function g. However, this method (1) has limitations on the function form from which an inverse function can be theoretically derived. It becomes difficult to theoretically derive the inverse function of f when the degree is cubic or higher. (2) Even if f is a quadratic function, there are two types of inverse functions for square root functions: + and -, and the appropriate one must be selected. Care must be taken with the domain and range, and calculations do not work when the value inside the root sign is negative. Furthermore, there are problems such as a high computational load. In contrast, according to this embodiment, instead of finding the function f, the set of points is inverted and then an approximate curve is fitted, so there are no constraints on the function form. Furthermore, the process of inversion on the line Q simply involves transposing the x and y coordinates, making the computation easier and reducing the computational load compared to calculating an inverse function.

[0022] (operation) FIG. 6 is a flowchart illustrating an example of a flow rate estimation process according to the embodiment. The flow rate estimation device 10 accumulates the estimated and actual measured values ​​of hot and cold water flow rates (step S1). The data acquisition unit 11 accumulates the measurement values ​​and measurement times of the flow rate sensor 99 in the memory unit 15, and the flow rate estimation unit 12 accumulates the estimated flow rate values ​​and estimated times corresponding to the measurement values ​​of the flow rate sensor 99 in the memory unit 15. Next, the correction unit 13 derives a function for finding the actual measured values ​​from the estimated flow rate values ​​(step S2). As explained using Figure 5, the correction unit 13 inverts each point on the scatter plot to a position that is symmetrical with respect to y = x, and calculates a function (correction function g) for finding the actual measured values ​​from the estimated flow rate values ​​based on the distribution shape of the points after inversion. The correction unit 13 records the correction function g in the memory unit 15. This is the preliminary preparation stage. From this point on, the flow rate sensor 99 is no longer required.

[0023] Next, the flow rate estimation process during operation will be described. First, the data acquisition unit 11 acquires the measurement values ​​of the sensors 5 to 8 (step S3) and stores these measurement values ​​in the memory unit 15. Next, the flow rate estimation unit 12 estimates the flow rate of hot water supplied from the hot water storage tank 3 to the facility 4 using the measurement values ​​stored in the memory unit 15, the characteristics table of FIG. 4, and the above-mentioned formulas (7), (1'), and (3) (step S4). The flow rate estimation unit 12 outputs the estimated flow rate to the correction unit 13. Next, the correction unit 13 corrects the estimated value of the flow rate (step S5). The correction unit 13 substitutes the estimated value of the flow rate acquired from the flow rate estimation unit 12 into the correction function g calculated in step S2 to obtain the estimated value of the corrected flow rate. The output unit 14 outputs the flow rate corrected by the correction unit 13. Thereafter, the processes from step S3 onwards are repeatedly executed.

[0024] (effect) As described above, this embodiment can estimate the flow rate of hot water from the hot water storage tank 3 to the facility 4 in a hot water supply system 1 that does not have a permanent flow sensor 99. Therefore, it is possible to forecast hot water demand and create hot water storage plans even for hot water supply systems 1 that do not have a flow sensor 99. Furthermore, because the installation of a flow meter is unnecessary, the installation cost of the flow meter, the labor and costs required for installation and maintenance, labor for repairs due to flow meter failure, and complaints can be reduced. Furthermore, the flow rate can be estimated independently of the customer's system configuration (tank type, number of tanks, number of heat source units, piping length, piping diameter, piping height, etc.). Even in hot water supply systems equipped with a flow sensor 99, this can be used as a backup in case of failure or deterioration of the flow sensor 99. Furthermore, this embodiment can correct the estimated flow rate using a correction function g. For example, the characteristic table illustrated in FIG. 4 is used. However, because the values ​​in this characteristic table are design values, they differ from the heating capacity Q when generating hot water in an actual environment. The correction unit 13 can correct the error in the estimated flow rate value due to this difference by substituting the estimated value into the correction function g obtained from the actual measurement value and the estimated value. This improves the accuracy of the flow rate estimation, and improves the accuracy of the demand forecast and hot water storage plan.

[0025] Furthermore, the correction function g may be calculated for a hot water supply system that is equipped with a flow meter and installed in another facility with similar specifications and environment, and this correction function g may be used for the hot water supply system 1. In this case, correction using the correction function g can be performed even for a hot water supply system 1 that does not have a flow sensor 99 even temporarily.

[0026] 7 is a diagram showing an example of the hardware configuration of a flow rate estimation device according to each embodiment. A computer 900 includes a CPU 901, a main storage device 902, an auxiliary storage device 903, an input / output interface 904, and a communication interface 905. The flow rate estimation device 10 described above is implemented in a computer 900. Each of the above-described functions is stored in the form of a program in an auxiliary storage device 903. A CPU 901 reads the program from the auxiliary storage device 903, loads it in a main storage device 902, and executes the above-described processing in accordance with the program. The CPU 901 also allocates a storage area in the main storage device 902 in accordance with the program. The CPU 901 also allocates a storage area in the auxiliary storage device 903 for storing data being processed in accordance with the program.

[0027] A program for implementing all or part of the functions of the flow rate estimation device 10 may be recorded on a computer-readable recording medium, and the program may be loaded into a computer system and executed to perform processing by each functional unit. The term "computer system" as used herein includes hardware such as an OS and peripheral devices. Furthermore, if a WWW system is used, the term "computer system" also includes a homepage providing environment (or display environment). Furthermore, the term "computer-readable recording medium" refers to portable media such as CDs, DVDs, and USBs, as well as storage devices such as hard disks built into the computer system. Furthermore, if the program is distributed to the computer 900 via a communication line, the computer 900 that receives the program may load the program into the main storage device 902 and execute the above-described processing. Furthermore, the program may be for implementing part of the above-described functions, or may be capable of implementing the above-described functions in combination with a program already stored in the computer system.

[0028] As described above, several embodiments according to the present disclosure have been described, but all of these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope of the invention and its equivalents as defined in the claims, as well as in the scope and spirit of the invention.

[0029] <Additional Notes> The flow rate estimation device, the flow rate estimation method, and the program described in each embodiment can be understood, for example, as follows.

[0030] (1) A flow rate estimation device according to a first aspect is a flow rate estimation device that estimates the flow rate of hot water supplied from a hot water supply system that includes a heat source machine and a hot water storage tank that stores hot water produced by the heat source machine, and includes a flow rate estimation unit that estimates the amount of hot water that flows into the hot water storage tank based on a first temperature that is the temperature of water flowing into the heat source machine, a second temperature that is the temperature of hot water supplied from the heat source machine to the hot water storage tank, and the heating capacity of the heat source machine calculated based on the first temperature, the second temperature, and an outside air temperature, and estimates the flow rate of hot water supplied from the hot water storage tank based on the inflow rate and changes in the amount of hot water stored in the hot water storage tank; and a correction unit that acquires multiple data sets of estimated values ​​of flow rate and actual measured values ​​of flow rate of hot and cold water corresponding to the estimated values, plots the multiple data sets on a graph using the estimated values ​​and the actual measured values ​​as coordinate axes based on the acquired multiple data sets, inverts the points indicated by the plotted estimated values ​​and the actual measured values ​​to positions that are linearly symmetrical about a line on the graph where the estimated values ​​and the actual measured values ​​are equal, calculates an approximation function that approximates the distribution shape of the points after inversion as a correction function that converts the estimated values ​​to the actual measured values, and corrects the estimated values ​​estimated by the flow rate estimation unit based on the correction function. This makes it possible to estimate the flow rate even without a flow meter for measuring the flow rate of hot water supplied from the hot water storage tank, and also improves the accuracy of the estimated flow rate.

[0031] (2) A flow rate estimation device according to a second aspect is a flow rate estimation device according to (1), wherein the correction unit inverts the points to positions that are symmetrical about the line by swapping the plotted estimated values ​​and the plotted measured values. This makes it easy to flip the points indicated by the estimated values ​​and the measured values ​​to positions that are symmetrical about the line y=x.

[0032] (3) A flow rate estimation method according to a third aspect is a method for estimating the flow rate of hot water supplied from a hot water supply system including a heat source machine and a hot water storage tank for storing hot water produced by the heat source machine, the method comprising the steps of: estimating an inflow rate of hot water into the hot water storage tank from a first temperature that is the temperature of water flowing into the heat source machine; a second temperature that is the temperature of hot water supplied from the heat source machine to the hot water storage tank; and the heating capacity of the heat source machine calculated based on the first temperature, the second temperature, and an outside air temperature; estimating the flow rate of hot water supplied from the hot water storage tank from the inflow rate and a change in the amount of hot water stored in the hot water storage tank; and The method includes a step of acquiring multiple data sets of estimated values ​​of water flow rate and actual measured values ​​of hot and cold water flow rate corresponding to the estimated values, plotting the multiple data sets on a graph with the estimated values ​​and the actual measured values ​​as coordinate axes based on the acquired multiple data sets, inverting the points indicated by the plotted estimated values ​​and the actual measured values ​​to positions that are linearly symmetrical about the line on the graph where the estimated values ​​and the actual measured values ​​are equal, calculating an approximation function that approximates the distribution shape of the points after inversion as a correction function that converts the estimated values ​​to the actual measured values, and correcting the estimated values ​​estimated in the estimating step based on the correction function.

[0033] (4) A program according to a fourth aspect is a process for estimating the flow rate of hot water supplied from a hot water supply system including a heat source machine and a hot water storage tank for storing hot water produced by the heat source machine, the program including the steps of: estimating the amount of hot water flowing into the hot water storage tank from a first temperature which is the temperature of water flowing into the heat source machine; a second temperature which is the temperature of hot water supplied from the heat source machine to the hot water storage tank; and the heating capacity of the heat source machine calculated based on the first temperature, the second temperature, and an outside air temperature; estimating the flow rate of hot water supplied from the hot water storage tank from the inflow rate and changes in the amount of hot water stored in the hot water storage tank; and calculating the flow rate of hot water estimated by the method of the estimating step. The method includes acquiring multiple data sets of estimated values ​​of hot water flow rate and actual measured values ​​of hot water flow rate corresponding to the estimated values, plotting the multiple data sets on a graph based on the acquired multiple data sets with the estimated values ​​and the actual measured values ​​as coordinate axes, inverting the points indicated by the plotted estimated values ​​and the actual measured values ​​to positions that are linearly symmetrical about the line on the graph where the estimated values ​​and the actual measured values ​​are equal, calculating an approximation function that approximates the distribution shape of the points after inversion as a correction function that converts the estimated values ​​to the actual measured values, and correcting the estimated values ​​estimated in the estimating step based on the correction function. [Explanation of symbols]

[0034] 1. Hot water system 2...Heat source machine 3. Hot water tank 4. Facilities 5, 6, 8...Temperature sensor 7. Water level sensor 99···Flow sensor 100A controller 100B Edge Server 100C···Cloud Server 10...Flow rate estimation device 11. Data acquisition section 12...Flow rate estimation section 13 Correction section 14. Output section 15...Storage section 900···Computer 901 CPU 902...Main memory 903...Auxiliary storage device 904 Input / Output Interface 905···Communication Interface

Claims

1. A flow rate estimation device that estimates the flow rate of hot water supplied from a hot water supply system that includes a heat source machine and a hot water storage tank that stores hot water produced by the heat source machine, a flow rate estimation unit that estimates the amount of hot water flowing into the hot water storage tank from a first temperature that is the temperature of water flowing into the heat source machine, a second temperature that is the temperature of hot water supplied from the heat source machine to the hot water storage tank, and the heating capacity of the heat source machine calculated based on the first temperature, the second temperature, and the outside air temperature, and estimates the flow rate of hot water supplied from the hot water storage tank from the inflow rate and changes in the amount of hot water stored in the hot water storage tank; a correction unit that acquires a plurality of data sets of estimated values ​​of the hot and cold water flow rates estimated by the flow rate estimation unit and actual measured values ​​of the hot and cold water flow rates corresponding to the estimated values, plots the plurality of data sets on a graph using the estimated values ​​and the actual measured values ​​as coordinate axes based on the acquired plurality of data sets, inverts the points indicated by the plotted estimated values ​​and the actual measured values ​​to positions that are line-symmetrical about a line on the graph where the estimated values ​​and the actual measured values ​​are equal, calculates an approximation function that approximates the distribution shape of the inverted points as a correction function that converts the estimated values ​​to the actual measured values, and corrects the estimated values ​​estimated by the flow rate estimation unit based on the correction function; A flow rate estimation device comprising:

2. the correction unit inverts the points to positions that are symmetrical with respect to the straight line by swapping the plotted estimated values ​​and the plotted measured values. The flow rate estimating device according to claim 1 .

3. A flow rate estimation method for estimating a flow rate of hot water supplied from a hot water supply system including a heat source machine and a hot water storage tank for storing hot water produced by the heat source machine, a step of estimating the amount of hot water flowing into the hot water storage tank from a first temperature which is the temperature of water flowing into the heat source machine, a second temperature which is the temperature of hot water supplied from the heat source machine to the hot water storage tank, and the heating capacity of the heat source machine calculated based on the first temperature, the second temperature, and the outside air temperature, and estimating the flow rate of hot water supplied from the hot water storage tank from the inflow amount and changes in the amount of hot water stored in the hot water storage tank; a step of acquiring a plurality of data sets of estimated values ​​of the hot and cold water flow rate estimated by the method of the estimating step and actual measured values ​​of the hot and cold water flow rate corresponding to the estimated values, plotting the plurality of data sets on a graph with the estimated values ​​and the actual measured values ​​as coordinate axes based on the acquired plurality of data sets, inverting the points indicated by the plotted estimated values ​​and the actual measured values ​​to positions that are line-symmetrical about the line on the graph where the estimated values ​​and the actual measured values ​​are equal, calculating an approximation function that approximates the distribution shape of the inverted points as a correction function that converts the estimated values ​​to the actual measured values, and correcting the estimated values ​​estimated in the estimating step based on the correction function; A flow rate estimation method having the following:

4. On the computer, A process for estimating a flow rate of hot water supplied from a hot water supply system including a heat source machine and a hot water storage tank for storing hot water produced by the heat source machine, a step of estimating the amount of hot water flowing into the hot water storage tank from a first temperature which is the temperature of water flowing into the heat source machine, a second temperature which is the temperature of hot water supplied from the heat source machine to the hot water storage tank, and the heating capacity of the heat source machine calculated based on the first temperature, the second temperature, and the outside air temperature, and estimating the flow rate of hot water supplied from the hot water storage tank from the inflow amount and changes in the amount of hot water stored in the hot water storage tank; a step of acquiring a plurality of data sets of estimated values ​​of the hot and cold water flow rate estimated by the method of the estimating step and actual measured values ​​of the hot and cold water flow rate corresponding to the estimated values, plotting the plurality of data sets on a graph with the estimated values ​​and the actual measured values ​​as coordinate axes based on the acquired plurality of data sets, inverting the points indicated by the plotted estimated values ​​and the actual measured values ​​to positions that are line-symmetrical about the line on the graph where the estimated values ​​and the actual measured values ​​are equal, calculating an approximation function that approximates the distribution shape of the inverted points as a correction function that converts the estimated values ​​to the actual measured values, and correcting the estimated values ​​estimated in the estimating step based on the correction function; A program that executes a process having the above steps.

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