Method for estimating the performance of heat source equipment

Abstract

To provide a performance estimation method for a heat source device capable of simply and accurately estimating performance of an actual heat source device.SOLUTION: A performance estimation method for a heat source device comprises steps of deriving an approximation expression representing the relation between a measured value representing the power consumption of an actual heat source device and manufacturer's values representing the power consumption, and, based on the approximation expression, correcting a power characteristic value of the heat source device depending on manufacturer's specification values in accordance with the actual device. It is possible to create the approximate expression using a plurality of data that do not match operation conditions, and it is also possible to correct the power characteristic value by applying the data to the power characteristic value that does not match the operation conditions with the data used for deriving the approximate expression.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for estimating the performance of an actual heat source device used for air conditioning. [Background technology]

[0002] 2. Description of the Related Art In office buildings, commercial facilities, and various other buildings, the power consumption of heat source equipment used for air conditioning may be calculated when calculating the energy consumption of air conditioning equipment and formulating an operation plan.

[0003] The performance of the heat source device is shown, for example, in a diagram as shown in FIG. 7. In the graph of FIG. 7, a COP (Coefficient of Performance) is assumed as a value indicating the performance of the heat source device (hereinafter, in this specification, this will be referred to as a "power characteristic value" as necessary), and the relationship of the COP to the heat source load factor is shown as a curve (referred to as a "power characteristic curve"). In the example shown here, three types of cooling water temperatures (inlet temperatures) are assumed as operating conditions, and the power characteristic curves at each cooling water temperature (A°C, B°C, C°C) are displayed. The heat source load factor on the horizontal axis is the value obtained by dividing the amount of generated heat by the rated amount of generated heat of the heat source device. The COP on the vertical axis is also called the coefficient of performance, and is the value obtained by dividing the amount of generated heat by the power consumption (energy consumption). Note that other conditions (cooling water outlet temperature, flow rate, etc.) are set as fixed values.

[0004] A diagram showing the performance of such a heat source device (called a "power characteristic diagram") is provided, for example, by a manufacturer that manufactures and sells the heat source device, or is created from data provided in the form of a table by the manufacturer. Then, under the condition that the cooling water is at a specific temperature (for example, the inlet temperature is A°C), the amount of heat generated according to the heat source load rate and the power consumption (energy consumption) at that time can be obtained from this graph. Note that, although the graph in FIG. 7 shows three patterns of curves corresponding to three types of cooling water temperatures, power characteristic curves for cases where the cooling water temperature is different from these can also be appropriately created based on the illustrated power characteristic curves and used. For example, when the cooling water temperature is between A°C and B°C, a curve that is intermediate between the curve showing A°C and the curve showing B°C can be assumed, and the amount of heat generated and the power consumption (energy consumption) can be obtained based on the curve.

[0005] However, such a graph based on the manufacturer's data is based only on the performance in the specifications, and the actual equipment does not necessarily perform as shown. The performance of heat source equipment varies from one to another, and an error of about ±5 to 15% from the specification value is allowed for the performance of the actual equipment. In other words, the performance of a heat source equipment varies within a range of ±5 to 15% from the specification value when it is new. Moreover, when the heat source equipment starts operating, its performance changes over time due to aging deterioration, and the power characteristics gradually deviate from the specification value. For this reason, even if the performance of the heat source equipment is estimated using a graph like that in Figure 7 based on the manufacturer's specification value, it may not necessarily be an optimal estimate according to the performance of the actual equipment.

[0006] In order to accurately estimate the performance of an actual machine, it is possible to create a new graph of power characteristics like that shown in Fig. 7 from data collected during operation of the actual machine, but this requires measuring the COP while changing the heat source load rate for each condition, which is an enormous amount of work.In addition, in actual operation, the conditions are almost never as wide as those used in manufacturer tests, so it is difficult to obtain enough data to draw a power characteristic curve.

[0007] Therefore, various techniques have been proposed to estimate the performance of the actual machine as accurately as possible by assuming a difference between the specification values ​​and the performance of the actual machine and appropriately correcting the data based on the specification values ​​(for example, see Patent Document 1 below). [Prior art documents] [Patent documents]

[0008] [Patent Document 1] JP 2019-90585 A Summary of the Invention [Problem to be solved by the invention]

[0009] However, in many technologies that attempt to estimate the performance of an actual device by correcting specification values, including the technology described in Patent Document 1, it is necessary to accumulate a certain amount of data on the actual device, and it is difficult to perform satisfactory corrections and performance estimations for the overall power characteristics when there is little operational data on the actual device. In addition, corrections often require complex calculations, and a method for easily and accurately estimating the performance of an actual heat source device has not yet been established.

[0010] In view of the above circumstances, the present invention provides a method for estimating the performance of a heat source device, which can easily and accurately estimate the performance of an actual heat source device. [Means for solving the problem]

[0011] The present invention derives an approximation formula that represents the relationship between the actual measured value of the power consumption of the actual heat source device and the manufacturer's value of the power consumption, Based on the above approximation formula, the power characteristic value of the heat source device according to the manufacturer's specifications is corrected to match the actual device. Processing is provided. Applying the approximation formula to a power characteristic value whose operating conditions do not match those of the data used to derive the approximation formula to correct the power characteristic value. The present invention relates to a method for estimating the performance of a heat source device, characterized by the above.

[0012] In the heat source device performance estimation method of the present invention, the approximation formula can be created using a plurality of data whose operating conditions do not match each other.

[0014] In the heat source device performance estimation method of the present invention, the approximation formula may be a linear formula.

[0015] In the method for estimating performance of a heat source device of the present invention, a power consumption ratio, which is a relative value with respect to a rated value, can be used as the value representing the power consumption.

[0016] In the heat source device performance estimation method of the present invention, only data that satisfies predetermined requirements can be used to derive the approximation formula. Effect of the Invention

[0017] According to the heat source device performance estimation method of the present invention, it is possible to achieve the excellent effect of estimating the performance of the actual heat source device simply and accurately. [Brief description of the drawings]

[0018] [Figure 1] 4 is a flowchart illustrating an example of a procedure for executing a performance estimation method for a heat source device according to an embodiment of the present invention. [Diagram 2] 4 is a graph showing an example of actual operation data obtained by operating an actual machine plotted on a power characteristics diagram. [Diagram 3] 11 is a graph showing another example of a state in which actual operating data obtained by operating an actual machine is plotted on a power characteristics diagram. [Figure 4] FIG. 11 is a scatter diagram showing an example of the relationship between the actual measured value and the manufacturer's value of the power consumption ratio. [Diagram 5] This is a diagram in which a straight line expressing an approximation equation of the relationship between the actual measured value of the power consumption ratio and the manufacturer's value, calculated based on the scatter diagram of FIG. 4, is drawn in the scatter diagram. [Figure 6] 11 is a graph showing an example of a power characteristic diagram before and after correction. [Figure 7] 4 is a graph showing an example of a power characteristic diagram of a heat source device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0020] 1 is a flowchart showing an example of a procedure for executing a performance estimation method for a heat source device according to an embodiment of the present invention. Hereinafter, a procedure for estimating the performance of an actual heat source device will be described based on this flowchart.

[0021] First, a power characteristic diagram based on the manufacturer's specifications is obtained (step S1). This power characteristic diagram may be provided by the manufacturer itself, or a curve graph may be created from data including the power characteristic value (COP) described in documents such as catalogs and specifications provided by the manufacturer. The power characteristic diagram obtained here is, for example, a graph as shown in FIG. 7.

[0022] Next, the actual device is operated to obtain operation data required to grasp the power characteristics of the heat source device (step S2). This actual device of the heat source device refers to a heat source device that is incorporated into an air conditioning system that is actually in commercial operation in an office building, hospital, factory, etc., and operates according to actual fluctuations in outside air and load. The operation data can be obtained, for example, from the log of a control device of the heat source device that constitutes the air conditioning system. That is, a control device called an EMS (Energy Management System) or the like records various data related to the operation of the actual device of the heat source device, such as the actual measured value of the power consumption of the heat source device, the load heat amount, the flow rate of the cooling water, the inlet temperature of the cooling water, etc., from time to time, so that the necessary data can be obtained from the log of this control device.

[0023] If the data obtained in step S2 were plotted on the power characteristic diagram shown in Fig. 7, it would look like the points shown in Fig. 2 or 3, for example. That is, the heat source load factor at each point during operation of the actual equipment and the coefficient of performance (COP) at that time can be obtained from the data obtained in step S2, and the graphs in Figs. 2 and 3 plot these data at each point on the power characteristic diagram in Fig. 7. Note that each point in Fig. 2 shows data obtained as a result of operation in a short period of time, while each point in Fig. 3 shows data obtained as a result of operation under a wide range of conditions over a longer period of time. Compared to Fig. 3, the points in Fig. 2 show similar operating conditions because the weather did not change much throughout the data acquisition period, and the range of acquired data is narrow.

[0024] With respect to the operation data at each time point acquired in step S2, the relative value of the actual power consumption (measured value) of the heat source device to the rated value of the power consumption of the actual device (hereinafter referred to as the "power consumption ratio") is calculated (step S3). The power consumption ratio can be expressed, for example, by the following formula, and the measured value of the power consumption ratio can be calculated from the measured value of the power consumption obtained from the operation data and the rated value based on the manufacturer's specifications. Power consumption ratio [%] = (power consumption / rated value) x 100 ……(1)

[0025] Next, for the operation data at each time point acquired in step S2, a value on the specification of the power consumption ratio (hereinafter referred to as the "manufacturer's value of the power consumption ratio") is calculated from the manufacturer's specification values ​​under the same operating conditions (cooling water inlet temperature, cold water outlet temperature, cooling water flow rate, and heat source load rate) (step S4). This manufacturer's value of the power consumption ratio can be calculated using the above formula (1) based on the power characteristic diagram according to the manufacturer's specification values ​​as shown in FIG. 7. That is, if certain cooling water inlet temperature, cold water outlet temperature, cooling water flow rate, and heat source load rate are given as conditions, the COP according to the manufacturer's specification values ​​under the same operating conditions can be obtained from the power characteristic diagram shown in FIG. 7. Furthermore, the power consumption can be obtained as the product of the load heat amount in the heat source device and the reciprocal of the COP, and the load heat amount is obtained as the product of the rated capacity of the heat source device and the heat source load rate, so the manufacturer's value of the power consumption ratio can be obtained from the power characteristic diagram in FIG. 7 and the above formula (1).

[0026] In this way, through steps S3 and S4, the actual measured value of the power consumption ratio at a certain point in time and the manufacturer's value of the power consumption ratio under the same operating conditions (cooling water inlet temperature, cooling water outlet temperature, cooling water flow rate, and heat source load factor) are calculated. In the following step S5, these ratios are calculated. Furthermore, the same process is repeated for the operating data at each point in time, and a scatter diagram showing the relationship between the actual measured value of the power consumption ratio and the manufacturer's value is created, as shown in Figure 4.

[0027] In step S6, from the data plotted in the scatter diagram, data during stable operation that meets certain requirements is selected and extracted as data to be used in the subsequent steps to derive an approximation formula and correct the power characteristic value (trimming process). Specifically, for example, by excluding the data that falls under the following category, a more appropriate approximation formula can be derived and the power characteristic value can be suitably corrected. - Data for a period of time (e.g. 30 minutes) after the actual heat source equipment is started. This is because the energy consumption until chilled water can be generated stably and continuously cannot be used in an approximation. Note that cooling water is used to remove the waste heat used to generate chilled water, and for example, the inlet temperature of a heat source equipment such as a refrigerator condenser is 32°C and the outlet temperature is 37°C, so the water leaves the equipment at a high temperature. - Data for low load (for example, when the heat source load rate is below 30%). When the heat source load rate is below the lower limit for continuous operation, the heat source equipment may operate in on-off mode rather than continuous mode, and data may be collected when the operation is not stable. Data when the heat source is off. This is to avoid the data at the origin of the scatter plot (see Figure 4) affecting the approximation formula. Data from operations under conditions different from normal operation, such as during maintenance, to avoid the effect on the approximation formula due to operating conditions different from normal operation (for example, changes in the cooling water flow rate).

[0028] Based on the data extracted in this way, an approximation formula expressing the relationship between the actual measured value of the power consumption ratio and the manufacturer's value is derived (step S7). If the approximation formula is a simple linear formula such as the following formula (2), it is easy to derive the approximation formula and to correct the power characteristic value thereafter. X is the actual measured value of the power consumption ratio, Y is the manufacturer's value of the corrected power consumption ratio, and a and b are constants. The relationship expressed by this approximation formula is shown by the dashed line in Figure 5. Y = aX + b ……(2)

[0029] Furthermore, the coefficient of performance (COP) obtained as the power characteristic obtained as the manufacturer's specification value is corrected based on the above formula (2) (step S8). The coefficient of performance obtained as the power characteristic presented by the manufacturer is provided in the form of a table, for example, as described above, or can be obtained as the values ​​of each point on a power characteristic diagram as shown in FIG. 7. If the power consumption ratio is calculated based on these values, each will be a value corresponding to X on the right side of the above formula (2), but these values ​​are corrected to a value such that the value corresponding to Y on the left side is calculated as the power consumption ratio. Next, the power characteristic diagram is recreated based on the corrected power characteristic values ​​(step S9). The power characteristic curve in the recreated power characteristic diagram is, for example, a curve as shown by the dashed line in FIG. 6. The solid line indicates the power characteristic curve according to the manufacturer's specification value, and is the same as the power characteristic curve shown in FIG. 7. The procedure for creating the power characteristic curve will be described below. (1) Substitute the manufacturer's value for the power consumption ratio (e.g., multiple values ​​in 10% increments) for X in Y=aX+b to calculate the corrected power consumption ratio. (2) Calculate the corrected COP value = (heat generated under heat source load conditions of manufacturer's value of power consumption ratio) / corrected power consumption = 100 x heat generated / (corrected power consumption ratio x rated value) (3) Create a COP curve by interpolating each point of the corrected COP value. It becomes.

[0030] In the above series of steps, the scatter diagrams shown in FIG. 4 and FIG. 5 and the approximation formula shown in FIG. 5 and formula (2) can be created using multiple data whose operating conditions do not match each other. The operating data shown by dots in FIG. 2 and FIG. 3 contain a mixture of data collected under various operating conditions (cooling water heat source inlet temperature, cooling water flow rate, chilled water outlet temperature, heat source load factor). Normally, it is necessary to extract data groups whose operating conditions match each other and perform operations such as deriving an approximation formula and subsequent correction for each of these groups, but in this embodiment, these are unified using an index of the relationship between the actual measured value of the consumed power and the manufacturer's value, and can be handled as a whole. By doing so, even if the data group has a variation in the operating conditions at the time of collection, it is possible to derive an approximation formula for correction from a small amount of operating data. Moreover, since the consumed power used to derive the approximation formula here is a value that reflects the heat source load factor and COP, it is possible to appropriately correct the power characteristics by using this value. In addition, by using the unified value in this way, it is possible to derive an approximation formula for correction by a simple calculation as described above. If a linear expression is used as the approximation, the necessary calculations are much simpler.

[0031] In the above procedure, the approximate expression represented by the formula (2) can be applied to the power characteristic value whose operating conditions do not match those of the data used to derive the approximate expression, to correct the power characteristic value. That is, even if the actual measurement data on which the correction is based is obtained only under limited operating conditions as shown by the dots in FIG. 2, steps S2 to S7 are executed based on the operating data to derive an approximate expression corresponding to the above formula (2), and the approximate expression can be applied to the entire power characteristic diagram, thereby correcting the entire power characteristic diagram widely, not limited to the range of the actually obtained operating data. As described above, in this embodiment, each operating data is unified and handled by the index of the relationship between the actual measured value of the consumed power and the manufacturer's value, regardless of the operating conditions. Therefore, even if the operating data is collected under operating conditions different from the power characteristic value according to the manufacturer's specification value, the approximate expression derived based on the data can be used to correct the power characteristic value. For example, when using a conventional method of redrawing a power characteristic curve using operating data of an actual machine, only a limited power characteristic curve as shown by the dashed line in FIG. 2 can be drawn from operating data such as that shown by dots in FIG. 2. However, according to the method of this embodiment, a totally corrected power characteristic curve can be obtained as shown by the dashed line in FIG. 6.

[0032] In this case, "matching of operating conditions" does not mean that all operating conditions are strictly the same. In practice, the term "matching of operating conditions" is also used when the operating conditions are similar enough that they can be treated as the same. It also includes the matching of some of the operating conditions.

[0033] The above steps can be summarized as follows. When the relationship between the heat source load factor and the COP is plotted on a power characteristics diagram for the operating data at a certain point obtained in step S2, it is assumed that the point is located at the position indicated by the reference symbol P1 in FIG. 2. The operating data at the point corresponding to this point P1 includes the heat source load factor and the COP as well as the flow rate and temperature (inlet temperature) of the cooling water. Therefore, it is also possible to calculate the COP value (manufacturer's value) according to the specifications under the same conditions as the operating data at the point corresponding to this point P1. This manufacturer's value is plotted at the position indicated by the reference symbol P2, for example.

[0034] Therefore, the actual value of the power consumption ratio is calculated based on the data corresponding to point P1 (step S3), and the manufacturer's value of the power consumption ratio is calculated based on the data corresponding to point P2 (step S4), and these ratios are calculated. This is performed for each data, a scatter diagram is created (step S5), and an approximation formula is derived (step S7). The approximation formula thus obtained is applied to the entire power characteristic curve (steps S8, S9), and a corrected power characteristic diagram is obtained. In this way, even if only operating data under limited conditions is obtained, for example as shown in Figure 2, a generally corrected power characteristic diagram can be created, and a power characteristic diagram that is more realistic than the manufacturer's value can be obtained over a wide range.

[0035] The above-described procedure is merely an example, and when implementing the present invention, the content of some of the steps may be changed, the order of the steps may be changed, or other appropriate modifications may be made. For example, the calculation of the actual value of the power consumption ratio in step S3 and the calculation of the manufacturer's value in step S4 may be switched, or may be performed simultaneously in parallel. In addition, although the above description has been given of a case in which the extraction step in step S6 is performed after the scatter diagram is created in step S5, the scatter diagram may also be created based on data extracted in advance.

[0036] In addition, the above describes the case where the relationship between the actual measured value of power consumption and the manufacturer's value is calculated as a relative value (power consumption ratio), but when creating a scatter diagram like that shown in Figure 4 or deriving an approximation formula like that shown in Figure 5 or formula (2), absolute values ​​can be used instead of relative values ​​to represent power consumption. In that case, the actual measured value can be the power consumption value itself obtained from the operating data. Also, the manufacturer's value can be calculated using a power characteristic diagram like that shown in Figure 7.

[0037] As described above, in the above embodiment, an approximation formula expressing the relationship between the actual measured value of the value expressing the power consumption of the actual heat source device and the manufacturer's value of the value expressing the power consumption is derived, and the power characteristic value of the heat source device is corrected based on the manufacturer's specification value based on the approximation formula. In this way, by correcting the power characteristic value based on the manufacturer's specification value using the operation data of the actual device, even if there is little data obtained by operating the actual device, it is possible to obtain a highly accurate power characteristic diagram based on the operation data of the actual device. At that time, an approximation formula is created using the heat source load rate and the power consumption, which is a value related to the COP, and a good correction can be made by simple calculation by correcting the difference between the manufacturer's value and the actual measurement value.

[0038] In addition, in this embodiment, the approximation formula can be created using a plurality of data whose operating conditions do not match each other. In this way, even if the data group has variations in the operating conditions at the time of collection, it is possible to derive a suitable approximation formula for correction tailored to the actual machine from a small amount of operating data.

[0039] In this embodiment, the approximation formula can be applied to a power characteristic value whose operating conditions do not match those of the data used to derive the approximation formula to correct the power characteristic value. In this way, the power characteristic diagram can be corrected widely, without being limited to the range of actually obtained operating data.

[0040] In this embodiment, the approximation formula can be a linear formula, which makes it possible to easily derive the approximation formula and correct the power characteristic value.

[0041] In this embodiment, the value representing the power consumption can be a power consumption ratio, which is a relative value with respect to a rated value.

[0042] Furthermore, in this embodiment, only data that meets certain requirements can be used to derive the approximation formula.

[0043] Therefore, according to the above embodiment, the performance of the actual heat source device can be estimated simply and accurately.

[0044] Incidentally, the method for estimating performance of a heat source device of the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

Claims

1. Derive an approximation formula expressing the relationship between the actual measured value of the power consumption of the actual heat source device and the manufacturer's value of the power consumption; A process of correcting the power characteristic value of the heat source device according to the manufacturer's specification value to match the actual device based on the approximation formula, Applying the approximation formula to a power characteristic value whose operating conditions do not match those of the data used to derive the approximation formula to correct the power characteristic value. A method for estimating performance of a heat source device, comprising:

2. The approximation formula is created using multiple data whose operating conditions do not match each other. The performance estimation method for a heat source device according to claim 1 .

3. The approximation formula is a linear formula. The performance estimation method for a heat source device according to claim 1 or 2,

4. The power consumption ratio, which is a relative value to the rated value, is used as the value representing the power consumption. The performance estimation method for a heat source device according to any one of claims 1 to 3,

5. Only data that meets certain requirements is used in deriving the approximation formula. The performance estimation method for a heat source device according to any one of claims 1 to 4,

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