Heat exchanger performance estimation method, heat exchanger performance estimation system, and output device

Abstract

To provide a heat exchanger performance estimation method and a heat exchanger performance estimation system that allow simple estimation of performance of a heat exchanger, and an output device that outputs information useful for maintenance of the heat exchanger.SOLUTION: A heat exchanger performance estimation method comprises: computing a heat transfer coefficient from a cooled-fluid inlet temperature, a cooled-fluid outlet temperature, a cooled-fluid flow rate, a cooling-fluid inlet temperature, a cooling-fluid outlet temperature, and a cooling-fluid flow rate; deriving a predicted temperature, which is a predicted value of the cooled-fluid inlet temperature, on the basis of at least one of an assumed value of the cooling-fluid inlet temperature and a heat load; and estimating heat exchanger performance on the basis of the predicted temperature.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present disclosure relates to a heat exchanger performance estimation method, a heat exchanger performance estimation system, and an output device for the results of estimating the performance of a heat exchanger. [Background technology]

[0002] Heat exchangers are used in industrial fields to recover waste heat or maintain the temperature of a circulating fluid within an appropriate range. In heat exchangers, where a cooling fluid and a cooled fluid exchange heat through heat transfer tubes inside the heat exchanger, the heat transfer area decreases when the flow path is blocked due to the adhesion of dirt to the heat transfer tube surface or clogging of the heat transfer tube. This reduction in heat transfer area reduces the amount of heat exchanged in the heat exchanger. In other words, the performance of the heat exchanger decreases. In particular, in heat exchangers used in industrial fields, the cooling fluid and the cooled fluid themselves are often contaminated. Therefore, flow path blockage is likely to occur due to the adhesion of dirt to the heat transfer tube surface or clogging of the heat transfer tube. As a result, the performance of the heat exchanger is likely to decrease. Therefore, to maintain the performance of the heat exchanger, frequent maintenance work is required. There is a need for a method and system for easily estimating the performance of a heat exchanger in order to determine whether or how often maintenance work should be performed on the heat exchanger.

[0003] Patent Document 1 describes a system that uses a tracking simulator that reproduces the state of an actual plant in real time based on actual measured values ​​of the actual plant, selects a heat transfer coefficient as a tracking parameter for this tracking simulator, operates the tracking simulator in parallel with the actual plant, and calculates an estimated value for the heat transfer coefficient by adjusting the heat transfer coefficient until the actual measured value and the simulator value match, and determines the deterioration state of the heat transfer performance of a heat exchanger based on the changing trend of these estimated values.

[0004] Patent Document 2 describes a method for calculating the area required to cool a cooled medium to a set temperature based on predetermined values ​​related to heat exchange between the cooling medium and the cooled medium and the received temperature of the cooled medium and the temperature of the cooling medium, calculating the effective area of ​​the heat transfer tubes where heat exchange takes place based on the surface area and number of heat transfer tubes, measuring the outlet temperature of the cooled medium, and determining that the heat exchanger is abnormal if the calculated required area is smaller than the calculated effective area and the measured temperature of the cooled medium is higher than the received set temperature.

[0005] Patent Document 3 describes a method for evaluating and managing the fouling of a heat exchanger by calculating a fouling coefficient using the temperature coefficients of the film heat transfer coefficients inside and outside the tubes that make up the overall heat transfer coefficient, and by using the time-dependent change in the fouling coefficient and its rate of increase. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-163507 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-208861 [Patent Document 3] Japanese Patent Application Publication No. 2019-78456 Summary of the Invention [Problem to be solved by the invention]

[0007] The heat exchanger diagnostic system described in Patent Document 1 adjusts the heat transfer coefficient until the actual measured value and the simulator value match, resulting in an increased calculation load. The heat exchanger performance management method described in Patent Document 2 can determine whether the heat exchanger is normal or abnormal, but cannot directly determine the heat transfer coefficient of the heat exchanger. As a result, it is difficult to determine the degree of deterioration of the heat exchanger. The heat exchanger fouling evaluation method described in Patent Document 3 cannot take into account the effect of changes in heat transfer area due to blockage or thinning of heat transfer tubes.

[0008] Furthermore, the techniques described in Patent Documents 1 to 3 do not have a function for diagnosing how the temperature of the cooled fluid changes when disturbance factors such as the cooling fluid temperature or the heat load in the system change. When the temperature of the cooled fluid is within a regulated value in actual operation, it is necessary to determine whether the performance of the heat exchanger is good or bad based on the temperature of the cooled fluid. Therefore, the techniques described in Patent Documents 1 to 3 cannot accurately determine whether the current performance of the heat exchanger is good or bad within the range of fluctuations of possible disturbance factors because they cannot diagnose changes in the temperature of the cooled fluid. Furthermore, in equipment that manages the upper temperature limit of the cooled fluid, even if the technology described in Patent Document 1 can calculate the heat transfer coefficient of the heat exchanger, it is not easy to determine whether the performance of the heat exchanger is good or bad when the cooling fluid temperature or the heat load in the system fluctuates.

[0009] Therefore, an object of the present disclosure is to provide a heat exchanger performance estimation method and system that can easily estimate the performance of a heat exchanger by calculating a heat transfer coefficient through a simple calculation based on actual measurement data, predicting the temperature of the cooled fluid in response to changes in external factors such as the cooling fluid temperature or the heat load in the system based on the calculated heat transfer coefficient, and comparing the predicted cooled fluid temperature with a set threshold.An object of the present disclosure is also to provide an output device that can output the estimated performance of the heat exchanger as information useful for maintaining the heat exchanger. [Means for solving the problem]

[0010] (1) A heat exchanger performance estimation method according to an embodiment of the present disclosure is a method for estimating performance of a heat exchanger that transfers heat from a cooled fluid circulating through a system including a thermal load to a cooling fluid, the method including: calculating a heat transfer coefficient from the cooled fluid to the cooling fluid based on a cooled fluid inlet temperature, which is the temperature of the cooled fluid when it enters the heat exchanger; a cooled fluid outlet temperature, which is the temperature of the cooled fluid when it exits the heat exchanger; a flow rate of the cooled fluid; a cooling fluid inlet temperature, which is the temperature of the cooling fluid when it enters the heat exchanger; a cooling fluid outlet temperature, which is the temperature of the cooling fluid when it exits the heat exchanger; and a flow rate of the cooling fluid; calculating a predicted temperature, which is a predicted value of the cooled fluid inlet temperature, based on assumed values ​​of at least one of the cooling fluid inlet temperature or the thermal load, assuming that at least one of the cooling fluid inlet temperature or the thermal load is varied; and estimating performance of the heat exchanger based on the predicted temperature.

[0011] (2) The heat exchanger estimation method of (1) above may further include estimating, as the performance of the heat exchanger, at least one of the range of the cooling fluid inlet temperature or the range of the thermal load required for the cooled fluid inlet temperature to be equal to or lower than the upper temperature limit value of the cooled fluid.

[0012] (3) A heat exchanger performance estimation system according to one embodiment of the present disclosure includes a performance estimation device that estimates the performance of the heat exchanger by executing the heat exchanger performance estimation method of (1) or (2) above, and an output device that outputs the estimated performance of the heat exchanger.

[0013] (4) In the heat exchanger performance estimation system of (3) above, the output device may display the predicted temperature assuming that at least one of the cooling fluid inlet temperature or the heat load has fluctuated, and if the predicted temperature exceeds the upper temperature limit of the cooled fluid, may display that the heat exchanger is abnormal.

[0014] (5) An output device according to one embodiment of the present disclosure includes a communication unit that acquires the estimated performance of the heat exchanger from a performance estimation device that executes the heat exchanger performance estimation method of (1) or (2) above, and a display unit that displays the estimated performance of the heat exchanger.

[0015] (6) In the output device of (5) above, the display unit may display the predicted temperature in correspondence with an assumed value of at least one of the cooling fluid inlet temperature or the heat load as an estimated result of the performance of the heat exchanger.

[0016] (7) In the output device of (6) above, the display unit may display the assumed value of the cooling fluid inlet temperature, the assumed value of the heat load, and the predicted temperature in the form of a two-dimensional map, a three-dimensional graph, or a table, in association with each other.

[0017] (8) In any one of the output devices (5) to (7) above, the display unit may display the predicted temperature in the event that at least one of the cooling fluid inlet temperature or the heat load fluctuates.

[0018] (9) In the output device of (8) above, the display unit may display that the heat exchanger is abnormal when the predicted temperature exceeds the upper temperature limit of the cooled fluid. [Effects of the Invention]

[0019] The heat exchanger performance estimation method and system according to the present disclosure can predict the temperature of a cooled fluid by varying disturbance factors such as the temperature of the cooling fluid and the thermal load in a system. Therefore, when the temperature of the cooled fluid is within a regulated operational range, the temperature of the cooled fluid can be used as a basis for determining the quality of heat exchanger performance. As a result, heat exchanger performance can be easily estimated. Furthermore, an output device according to the present disclosure outputs the estimated heat exchanger performance as information useful for heat exchanger maintenance. [Brief explanation of the drawings]

[0020] [Figure 1]1 is a block diagram illustrating a configuration example of a heat exchanger performance estimation system according to the present disclosure. [Figure 2] FIG. 2 is a diagram illustrating an example of a system to which a heat exchanger is connected. [Figure 3] 10 is a graph showing an example of the relationship between the number of days elapsed since the cleaning of the heat exchanger and the heat transfer coefficient of the heat exchanger. [Figure 4] 10 is an example of a graph showing the relationship between the cooling fluid inlet temperature and the cooled fluid inlet temperature. [Figure 5] 1 is an example of a graph showing the relationship between the heat load of a system and the inlet temperature of a cooled fluid. [Figure 6] 1 is an example of a graph showing the relationship between the heat transfer coefficient of a heat exchanger and the inlet temperature of a fluid to be cooled. [Figure 7] 10 is an example of a map showing the relationship between the cooling fluid inlet temperature and the system heat load and the cooled fluid inlet temperature. [Figure 8] 1 is a flowchart illustrating an example of a procedure for estimating a heat transfer coefficient of a heat exchanger in a heat exchanger performance estimation method according to the present disclosure. [Figure 9] 10 is a flowchart illustrating an example of a procedure for outputting maintenance information of a heat exchanger in a heat exchanger performance estimation method according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, embodiments of a heat exchanger performance estimation method, a heat exchanger performance estimation system 1 (see FIG. 1), a performance estimation device 10 (see FIG. 1), and an output device 20 (see FIG. 1) according to the present disclosure will be described with reference to the drawings. The drawings are schematic and may differ from the actual devices. Furthermore, the following embodiments exemplify devices or methods for embodying the technical ideas of the present disclosure, and are not intended to limit the configuration to those described below. In other words, the technical ideas of the present disclosure can be modified in various ways within the technical scope defined in the claims.

[0022] The heat exchanger performance estimation method and heat exchanger performance estimation system 1 according to the present disclosure can estimate the possibility that a performance problem will occur in the heat exchanger 30 in the future, even if a performance problem in the heat exchanger 30 has not yet become apparent. The performance of the heat exchanger 30 is expressed by whether the temperature of the cooled fluid falls within a normal range. If the temperature of the cooled fluid falls within the normal range, the performance of the heat exchanger 30 is determined to be sufficient. The normal temperature range of the cooled fluid is defined as the range in which the temperature of the cooled fluid is equal to or lower than an upper temperature limit. The upper temperature limit of the cooled fluid may be set based on the operating temperature specifications of the cooled device 62 (see FIG. 1) connected to the cooled fluid circulation system 60 (see FIG. 1), as will be described later.

[0023] Here, the temperature of the cooled fluid, which is a function of the heat exchanger 30, may fluctuate due to external influences such as fluctuations in air temperature. For example, fluctuations in the temperature of the cooling fluid may cause the temperature of the cooled fluid to fluctuate and fall outside the normal range. In this case, the heat exchanger 30 does not have sufficient performance, and it can be diagnosed that the condition of the heat exchanger 30 is abnormal.

[0024] In the present disclosure, to estimate the performance of a heat exchanger 30, the heat transfer coefficient of the heat exchanger 30 and a predicted value of the temperature of the cooled fluid at the inlet of the heat exchanger 30 when subjected to external influences are calculated. The heat transfer coefficient of the heat exchanger 30 and the predicted value of the temperature of the cooled fluid at the inlet of the heat exchanger 30 when subjected to external influences are calculated with a low computational load. By comparing the predicted value of the temperature of the cooled fluid at the inlet of the heat exchanger 30 when subjected to external influences with a set upper temperature limit, it is possible to easily determine whether the performance of the heat exchanger 30 is sufficient. Furthermore, by comparing the predicted value of the temperature of the cooled fluid at the inlet of the heat exchanger 30 when subjected to external influences with a set upper temperature limit, the degree of performance degradation of the heat exchanger 30 can be grasped. Information on the degree of performance degradation of the heat exchanger 30 is useful for determining the timing of maintenance work on the heat exchanger 30, etc.

[0025] The performance estimation method and performance estimation device 10 according to the present disclosure allow for easy estimation of the performance of the heat exchanger 30. Furthermore, the output device 20 according to the present disclosure outputs the estimated performance of the heat exchanger 30 as information useful for maintenance work on the heat exchanger 30.

[0026] (Configuration example of heat exchanger performance estimation system 1) 1 , a heat exchanger performance estimation system 1 according to one embodiment includes a performance estimation device 10, an output device 20, and a measurement device 40. The heat exchanger performance estimation system 1 measures data of a heat exchanger 30 using the measurement device 40.

[0027] As illustrated in FIG. 2, the heat exchanger 30 is connected between a cooling fluid circulation system 50 and a cooled fluid circulation system 60 .

[0028] The cooling fluid flowing through the cooling fluid circulation system 50 may be, for example, circulating water (cooling water). The cooling fluid circulation system 50 is connected to an external cooling fluid supply facility. The cooling fluid is supplied from the external cooling fluid supply facility and circulates through the cooling fluid circulation system 50.

[0029] The cooled fluid circulation system 60 includes a cooled device 62, a tank 64, and a pump 66. The pump 66 circulates the cooled fluid within the cooled fluid circulation system 60. The tank 64 is configured to temporarily store the cooled fluid in the event of an excess of the cooled fluid within the cooled fluid circulation system 60. The cooled device 62 may be, for example, a morgoil (bearing) of a rolling mill used in a steel plate rolling line. When the cooled device 62 is a morgoil (bearing), the cooled fluid flowing through the cooled fluid circulation system 60 may be lubricating oil for the morgoil (bearing). The cooled device 62 may be, for example, an edge heater that heats the widthwise edge of a steel plate in a rolling mill using an induced current. When the cooled device 62 is an edge heater, the cooled fluid may be pure water that cools the body of the edge heater or an inverter used in the edge heater.

[0030] As the cooling fluid and the cooled fluid enter and exit the heat exchanger 30, heat is transferred from the cooled fluid to the cooling fluid. As a result, the temperature of the cooled fluid decreases. In the example of FIG. 2, the flow rate of the cooling fluid entering and exiting the heat exchanger 30 is m c The flow rate of the cooled fluid entering and leaving the heat exchanger 30 is expressed as m h The temperature at which the cooling fluid enters the heat exchanger 30 is also referred to as the cooling fluid inlet temperature, T c1 The temperature at which the cooling fluid exits the heat exchanger 30 is also referred to as the cooling fluid exit temperature, T c2 The temperature at which the cooled fluid enters the heat exchanger 30 is also referred to as the cooled fluid inlet temperature, T h1 The temperature at which the cooled fluid exits the heat exchanger 30 is also referred to as the cooled fluid exit temperature, T h2 It is expressed as:

[0031] The heat exchanger performance estimation system 1 estimates the performance of the heat exchanger 30 using the performance estimation device 10. The cooled fluid circulation system 60, the cooling fluid circulation system 50, and the heat exchanger 30 illustrated in FIG. 2 function to control the temperature of the cooled device 62 to be equal to or lower than the upper temperature limit. Specifically, heat generated in the cooled device 62 is transferred to the cooled fluid, and then transferred from the cooled fluid to the cooling fluid in the heat exchanger 30. In other words, the cooled device 62 is cooled by the functions of the cooled fluid circulation system 60, the cooling fluid circulation system 50, and the heat exchanger 30. As a result, the temperature of the cooled device 62 is controlled to be equal to or lower than the upper temperature limit.

[0032] Because the heat exchanger 30 controls the temperature of the cooled device 62 to be equal to or lower than the upper temperature limit, the performance of the heat exchanger 30 may be expressed as the temperature of the cooled device 62. In the cooled fluid circulation system 60, the temperature of the cooled fluid approaches the temperature of the cooled device 62 from the time it enters the cooled device 62 until it exits. Hereinafter, in this disclosure, it is assumed that the temperature of the cooled fluid matches the temperature of the cooled device 62 after it leaves the cooled device 62. It is also assumed that the temperature of the cooled fluid does not change from the time it leaves the cooled device 62 until it enters the heat exchanger 30. In this case, the temperature of the cooled device 62 matches the cooled fluid inlet temperature of the heat exchanger 30. Therefore, the performance of the heat exchanger 30 may be expressed as the cooled fluid inlet temperature of the heat exchanger 30.

[0033] The cooled fluid inlet temperature of the heat exchanger 30 is a measurable value. However, the cooled fluid inlet temperature of the heat exchanger 30 fluctuates depending on changes in the state of the heat exchanger 30 or changes in the heat generation amount or cooling fluid inlet temperature of the cooled device 62. The heat generated by the cooled device 62 is heat generated in the cooled fluid circulation system 60, and is also referred to as the heat load of the cooled fluid circulation system 60. Even if the cooled fluid inlet temperature of the heat exchanger 30 or the heat load of the cooled fluid circulation system 60 fluctuates, the heat exchanger 30 is required to control the temperature after the fluctuation to be below the upper temperature limit.

[0034] The performance estimation device 10 according to the present disclosure estimates fluctuations in the inlet temperature of the cooled fluid of the heat exchanger 30 as the performance of the heat exchanger 30. The performance estimation device 10 may estimate that the performance of the heat exchanger 30 is good if the temperature after the fluctuations is equal to or lower than the upper temperature limit. The performance estimation device 10 may estimate that the performance of the heat exchanger 30 is deteriorating if the temperature after the fluctuations is likely to exceed the upper temperature limit.

[0035] The heat exchanger performance estimation system 1 outputs the estimated performance of the heat exchanger 30 via the output device 20. The output device 20 may display maintenance information for the heat exchanger 30 based on the estimated performance of the heat exchanger 30. The maintenance information for the heat exchanger 30 may include information specifying the timing for performing maintenance work such as inspection, cleaning, part replacement, or repair of the heat exchanger 30. The maintenance information for the heat exchanger 30 may include information specifying the content of the maintenance work.

[0036] Each component of the heat exchanger performance estimation system 1 will be described below.

[0037] <Performance estimation device 10> As shown in FIG. 1, the performance estimation device 10 includes an estimation unit 11, a storage unit 12, and a communication unit 13.

[0038] The estimation unit 11 may be configured to include, for example, a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit) in order to control or manage various functions of the performance estimation device 10. The estimation unit 11 may implement the functions of the performance estimation device 10 by reading and executing a program stored in the storage unit 12.

[0039] The storage unit 12 stores various types of information or data used in the performance estimation device 10. The storage unit 12 may store, for example, a program executed by the estimation unit 11, or data or processing results used in the processing executed by the estimation unit 11. The storage unit 12 may function as a work memory for the estimation unit 11. The storage unit 12 may be configured to include, for example, a semiconductor memory, but is not limited to this. The storage unit 12 may be configured as, for example, an internal memory of the estimation unit 11, or may be configured as an electromagnetic recording medium such as a hard disk drive (HDD) accessible from the estimation unit 11. The storage unit 12 may be configured as a non-transitory readable medium. The storage unit 12 may be configured integrally with the estimation unit 11, or may be configured separately from the estimation unit 11.

[0040] The communication unit 13 may be configured to include a communication interface for communicating with other devices, such as the output device 20 or the measurement device 40, via a wired or wireless connection. The communication interface may be configured to be able to communicate with other devices via a network. The communication unit 13 may be configured to include an input / output port for inputting and outputting data to and from other devices. The communication unit 13 may communicate based on a wired communication standard or a wireless communication standard. The wireless communication standard may include a cellular phone communication standard such as 4G (4th Generation) or 5G (5th Generation). The wireless communication standard may also include IEEE802.11, Bluetooth (registered trademark), and the like. The communication unit 13 may support one or more of these communication standards. The communication unit 13 is not limited to these examples and may communicate with other devices or input and output data based on various standards.

[0041] The performance estimation apparatus 10 may include an input device or an output device. The input device may be configured the same as or similar to the input device of the output apparatus 20 described later. The output device may be configured the same as or similar to the output device of the output apparatus 20 described later.

[0042] The performance estimation device 10 may be realized in an on-premise environment, or may be realized using a cloud service. The performance estimation device 10 may also be realized in a form that combines an on-premise environment and a cloud service.

[0043] <Output device 20> The output device 20 includes a control unit 21, a storage unit 22, a communication unit 23, and a display unit 24.

[0044] The control unit 21 may be configured to include, for example, a CPU or a GPU in order to control or manage various functions of the output device 20. The control unit 21 may realize the functions of the output device 20 by reading and executing a program stored in the storage unit 22.

[0045] The memory unit 22 stores various types of information or data used by the output device 20. The memory unit 22 may store, for example, a program executed in the control unit 21, or data or processing results used in processing executed in the control unit 21. The memory unit 22 may function as a work memory for the control unit 21. The memory unit 22 may be configured identically or similarly to the memory unit 12 of the performance estimation device 10. The memory unit 22 may be configured integrally with the control unit 21, or may be configured separately from the control unit 21.

[0046] The communication unit 23 may be configured to include a communication interface for communicating with other devices such as the performance estimation device 10 via wired or wireless communication. The communication unit 23 may be configured identically or similarly to the communication unit 13 of the performance estimation device 10.

[0047] The display unit 24 displays various types of information or data as visual information such as characters, figures, or images so that the information or data can be recognized by a user of the heat exchanger performance estimation system 1. The display unit 24 may include various displays such as a liquid crystal display.

[0048] The output device 20 may include an input device that accepts input from a user of the heat exchanger performance estimation system 1. The input device may include, for example, a keyboard or physical keys, or may include a touch panel or touch sensor, or a pointing device such as a mouse. The input device is not limited to these examples and may include various other devices.

[0049] In addition to the display unit 24, the output device 20 may also include an audio output device that outputs various types of information or data as audio information such as sound. In addition to visual information or audio information, the output device 20 may also include a device that outputs information that the user can perceive with other senses.

[0050] The output device 20 may be realized in an on-premise environment, or may be realized using a cloud service. The output device 20 may also be realized in a form that combines an on-premise environment and a cloud service.

[0051] At least a part of the functions of the output device 20 may be realized by the performance estimation device 10. In other words, the performance estimation device 10 may include at least a part of the output device 20.

[0052] <Measuring device 40> The measuring device 40 measures data of the heat exchanger 30 and outputs the measurement results to the performance estimation device 10. The measuring device 40 includes temperature sensors that measure the cooling fluid inlet temperature, cooling fluid outlet temperature, and cooled fluid inlet temperature, cooled fluid outlet temperature of the heat exchanger 30. The measuring device 40 includes flow rate sensors that measure the flow rates of the cooling fluid and the cooled fluid.

[0053] (Example of operation of heat exchanger performance estimation system 1) In the heat exchanger performance estimation system 1 according to the present disclosure, the performance estimation device 10 estimates the fluctuation of the cooled fluid inlet temperature of the heat exchanger 30 as the performance of the heat exchanger 30. Furthermore, the output device 20 displays the estimated performance of the heat exchanger 30. Below, an example of the operation of the performance estimation device 10 and the output device 20 will be described.

[0054] <Calculation of the heat transfer coefficient of the heat exchanger 30> The cooled fluid inlet temperature estimated as the performance of the heat exchanger 30 is affected by fluctuations in the cooling fluid inlet temperature of the heat exchanger 30. The ratio between the amount of change in the cooling fluid inlet temperature of the heat exchanger 30 and the amount of change in the cooled fluid inlet temperature of the heat exchanger 30 is determined based on the heat transfer coefficient of the heat exchanger 30. Therefore, the estimation unit 11 may calculate the heat transfer coefficient of the heat exchanger 30 as the performance of the heat exchanger 30. In other words, the performance of the heat exchanger 30 may be represented by the heat transfer coefficient.

[0055] The heat transfer coefficient of the heat exchanger 30 is the ratio of the amount of heat exchanged to the logarithmic mean temperature difference of the heat exchanger 30. The heat transfer coefficient of the heat exchanger 30 is expressed as the product of the overall heat transfer coefficient of the heat exchanger 30 and the heat transfer area. Therefore, the relationship between the amount of heat exchanged, the logarithmic mean temperature difference, and the heat transfer coefficient of the heat exchanger 30 is expressed by the following formula (1). In formula (1), the amount of heat exchanged is represented by Q. When the logarithmic mean temperature difference is ΔT LMTDThe overall heat transfer coefficient is represented by U. The heat transfer area is represented by A.

number

[0056] According to formula (1), the heat transfer coefficient, which is the ratio of the amount of heat exchanged to the logarithmic mean temperature difference of the heat exchanger 30, is expressed as U×A. The value of the heat transfer coefficient is calculated as the product of the overall heat transfer coefficient (U) and the heat transfer area (A), so that the effect of performance degradation due to changes in the overall heat transfer coefficient caused by contamination of the heat exchanger 30 and the effect of performance degradation due to changes in the heat transfer area caused by clogging of the heat exchanger 30 are reflected in the value of the heat transfer coefficient. Therefore, the estimation unit 11 can estimate the performance degradation of the heat exchanger 30 based on the calculated heat transfer coefficient value (U×A).

[0057] In order to calculate the heat transfer coefficient of the heat exchanger 30, it is necessary to calculate the amount of heat exchanged by the heat exchanger 30 and the logarithmic mean temperature difference. The amount of heat exchanged by the heat exchanger 30 is calculated based on the specific heat and flow rate of the cooling fluid in the heat exchanger 30, the cooling fluid inlet temperature, and the cooling fluid outlet temperature. The amount of heat exchanged by the heat exchanger 30 is also calculated based on the specific heat and flow rate of the cooled fluid, the cooled fluid inlet temperature, and the cooled fluid outlet temperature. In other words, the amount of heat exchanged by the heat exchanger 30 can also be expressed by the following equation (2). In equation (2), when the flow rate of the cooled fluid is m h If the specific heat of the cooled fluid is c h The flow rate of the cooling fluid is expressed as m c If the specific heat of the cooling fluid is c c It is expressed as:

number

[0058] In equation (2), ΔT h is the cooled fluid inlet temperature (T h1 ) and cooled fluid outlet temperature (T h2 ) and the difference (T h1 -T h2 ) Therefore, the following equation (3) holds true.

number

[0059] In equation (2), ΔT c is the cooling fluid inlet temperature (T c1 ) and cooling fluid outlet temperature (T c2 ) and the difference (T c1 -T c2 ) Therefore, the following equation (4) holds true.

number

[0060] The specific heats of the cooling fluid and the cooled fluid are known because they are physical properties. Therefore, the estimation unit 11 can also calculate the amount of heat exchanged (Q) of the heat exchanger 30 by applying the measurement data of the flow rate of the cooled fluid, the inlet temperature of the cooled fluid, and the outlet temperature of the cooled fluid to the above-mentioned equations (2) and (3). The estimation unit 11 can also calculate the amount of heat exchanged (Q) of the heat exchanger 30 by applying the measurement data of the flow rate of the cooling fluid, the inlet temperature of the cooling fluid, and the outlet temperature of the cooling fluid to the above-mentioned equations (2) and (4).

[0061] Also, the logarithmic mean temperature difference (ΔT LMTD ) is calculated by the following equation (5) based on the cooled fluid inlet temperature, cooled fluid outlet temperature, and cooling fluid inlet temperature, cooling fluid outlet temperature.

number

[0062] The estimation unit 11 calculates the value of the heat exchange quantity (Q) calculated from the formulas (2) to (4) and the logarithmic mean temperature difference (ΔT LMTD ) to the above-mentioned formula (1), the value of the heat transfer coefficient expressed as U × A can be calculated. As a result, based on the measurement data on the cooled fluid and the cooling fluid of the heat exchanger 30, the estimation unit 11 can calculate the value of the heat transfer coefficient at the time the measurement data was obtained as the performance of the heat exchanger 30.

[0063] The estimation unit 11 can calculate and record the time transition of the value of the heat transfer coefficient by acquiring the time transition of the measurement data related to the cooled fluid and the cooling fluid. The estimation unit 11 can monitor the time transition of the heat transfer coefficient by recording the time transition of the value of the heat transfer coefficient. Based on the time transition of the heat transfer coefficient, the estimation unit 11 can confirm the rate at which the heat transfer coefficient decreases as the rate of deterioration of the performance of the heat exchanger 30.

[0064] For example, as shown in Figure 3, the heat transfer coefficient of the heat exchanger 30 decreases with the number of days that have passed. The number of days that have passed on the horizontal axis is the number of days that have passed since the heat exchanger 30 was in operation. The heat transfer coefficient on the vertical axis is a value calculated using the above-mentioned formulas (1) to (5). The horizontal axis specifies the timing at which cleaning was performed. It shows that the heat transfer coefficient decreases as the number of days that have passed since cleaning increases.

[0065] Based on the change over time in the heat transfer coefficient, the estimation unit 11 can estimate a future decrease in the heat transfer coefficient as a performance of the heat exchanger 30. In other words, the estimation unit 11 can estimate future deterioration in the performance of the heat exchanger 30. When the estimation unit 11 calculates the change over time in the heat transfer coefficient as shown in the graph of Fig. 3, for example, the estimation unit 11 may determine the timing for cleaning the heat exchanger 30 based on the estimated trend of the decrease in the heat transfer coefficient and output the determined timing as maintenance information.

[0066] The estimation unit 11 may acquire measurement data in real time and update the time transition of the heat transfer coefficient in real time. By the estimation unit 11 estimating the performance of the heat exchanger 30 in real time, deterioration of the performance of the heat exchanger 30 can be detected early.

[0067] <Estimation of cooled fluid inlet temperature when disturbance factors fluctuate> As described above, the estimation unit 11 can calculate the heat transfer coefficient of the heat exchanger 30 at the time of acquiring the measurement data based on the measurement data of the cooled fluid and the cooling fluid. Here, the cooled fluid inlet temperature of the heat exchanger 30, i.e., the temperature of the cooled device 62, is affected by fluctuations in external disturbance factors that are not factors of the heat exchanger 30 itself, such as the temperature of the cooling fluid or the magnitude of the heat load of the cooled fluid circulation system 60.

[0068] For example, when the temperature of the cooling fluid increases, the temperature of the cooled fluid also increases. As a result, even if the heat transfer coefficient of the heat exchanger 30 does not change, the temperature of the cooled device 62 increases. Furthermore, when the heat load of the cooled fluid circulation system 60 increases, the amount of heat exchanged by the heat exchanger 30 increases in proportion to the increase in the heat load. This is because, from the perspective of the heat balance between the cooling fluid circulation system 50 and the cooled fluid circulation system 60, it can be assumed that the magnitude of the heat load of the cooled fluid circulation system 60 matches the amount of heat exchanged by the heat exchanger 30. When the amount of heat exchanged by the heat exchanger 30 increases, the difference between the temperature of the cooled fluid and the temperature of the cooling fluid increases throughout the entire system. Therefore, the inlet temperature of the cooled fluid, i.e., the temperature of the cooled device 62, increases. As a result, even if the heat transfer coefficient of the heat exchanger 30 does not change, the temperature of the cooled device 62 increases.

[0069] As described above, even if the heat transfer coefficient of the heat exchanger 30 remains unchanged, the temperature of the cooled device 62 may fluctuate due to fluctuations in disturbance factors. The performance of the heat exchanger 30 is required to be such that the temperature of the cooled device 62 can be kept below an upper temperature limit even if it rises due to fluctuations in the disturbance factors. Therefore, the estimation unit 11 may estimate the range in which the cooled fluid inlet temperature, i.e., the temperature of the cooled device 62, may fluctuate when affected by the disturbance factors, and determine that the performance of the heat exchanger 30 has deteriorated if there is a possibility that the temperature of the cooled device 62 will exceed the upper temperature limit. The estimation unit 11 may output information indicating that the performance of the heat exchanger 30 has deteriorated as maintenance information. When the estimation unit 11 determines that the performance of the heat exchanger 30 has deteriorated, the estimation unit 11 may plan the content or timing of maintenance work for the heat exchanger 30 and output the plan as maintenance information.

[0070] The estimation unit 11 may use the calculation result of the heat transfer coefficient (U×A) of the heat exchanger 30 and the relationship of the above-mentioned formulas (1) to (5) to estimate the range in which the cooled fluid inlet temperature, i.e., the temperature of the cooled device 62, may fluctuate. For example, the estimation unit 11 can calculate the cooled fluid inlet temperature when the magnitude of the heat load of the cooled fluid circulation system 60 and the cooling fluid inlet temperature are each set to arbitrary values. In other words, the estimation unit 11 can estimate the cooled fluid inlet temperature without actually measuring the temperatures of the cooling fluid and the cooled fluid.

[0071] Specifically, by setting the cooling fluid inlet temperature and the magnitude of the heat load, i.e., the amount of heat exchanged by the heat exchanger 30, to arbitrary values, the estimation unit 11 can calculate the values ​​of the cooling fluid outlet temperature, the cooled fluid inlet temperature, and the cooled fluid outlet temperature, which are unknowns in equations (1) to (5), by solving equations (1) to (5).

[0072] The estimation unit 11 assumes that at least one of the magnitude of the heat load or the cooling fluid inlet temperature will fluctuate to any value within a range of possible fluctuations. The value assumed to fluctuate is also referred to as an assumed value. The estimation unit 11 calculates a predicted value of the cooled fluid inlet temperature corresponding to at least one assumed value of the magnitude of the heat load or the cooling fluid inlet temperature. The predicted value of the cooled fluid inlet temperature is also referred to as a predicted temperature.

[0073] The estimation unit 11 sets various values ​​between the upper and lower limits of the range of possible fluctuations for at least one of the magnitude of the heat load or the cooling fluid inlet temperature as assumed values, and calculates predicted values ​​of the cooled fluid inlet temperature corresponding to the assumed values, thereby being able to calculate the range in which the cooled fluid inlet temperature may fluctuate as the performance of the heat exchanger 30. The range in which the cooled fluid inlet temperature may fluctuate is also referred to as the predicted temperature fluctuation range.

[0074] The estimating unit 11 estimates the performance of the heat exchanger 30 based on a predicted value of the cooled fluid inlet temperature, i.e., the predicted temperature. For example, if the predicted temperature exceeds the upper temperature limit of the cooled device 62, the estimating unit 11 may determine that the performance of the heat exchanger 30 has deteriorated or that maintenance work is required. If the upper limit of the range in which the predicted temperature may fluctuate, i.e., the predicted temperature fluctuation range, exceeds the upper temperature limit of the cooled device 62, the estimating unit 11 may determine that the performance of the heat exchanger 30 has deteriorated or that maintenance work is required. The estimating unit 11 may output information indicating that the performance of the heat exchanger 30 has deteriorated or that maintenance work is required as maintenance information. If the estimating unit 11 determines that the performance of the heat exchanger 30 has deteriorated or that maintenance work is required, the estimating unit 11 may plan the content or timing of maintenance work for the heat exchanger 30 and output the plan as maintenance information.

[0075] Conversely, if the upper limit value of the predicted temperature fluctuation range is equal to or less than the upper temperature limit value of the cooled device 62, the estimation unit 11 may determine that there is no problem with the current performance of the heat exchanger 30 or that maintenance work does not need to be performed. In other words, if all predicted temperatures calculated by setting assumed values ​​over the entire range of possible fluctuations for both the magnitude of the heat load and the cooling fluid inlet temperature are equal to or less than the upper temperature limit value of the cooled device 62, the estimation unit 11 may determine that there is no problem with the current performance of the heat exchanger 30 or that maintenance work does not need to be performed.

[0076] As described above, the estimation unit 11 calculates the range in which the cooled fluid inlet temperature of the heat exchanger 30 may fluctuate when external factors such as the cooling fluid inlet temperature or the magnitude of the heat load of the cooled fluid circulation system 60 are assumed to fluctuate, thereby making it possible to estimate whether the current performance of the heat exchanger 30 is sufficient even when affected by fluctuations in external factors.

[0077] When the predicted temperature exceeds the temperature upper limit of the device to be cooled 62, that is, the temperature upper limit of the fluid to be cooled, the estimation unit 11 may estimate at least one of the range of the coolant inlet temperature or the range of the magnitude of the heat load necessary for the inlet temperature of the fluid to be cooled to be equal to or lower than the temperature upper limit of the fluid to be cooled as the performance of the heat exchanger 30. That is, the estimation unit 11 may estimate the allowable range of variation of the coolant inlet temperature or the magnitude of the heat load. By showing the conditions for the predicted temperature to be equal to or lower than the temperature upper limit of the fluid to be cooled as the allowable range of variation of the coolant inlet temperature or the heat load, the user of the heat exchanger performance estimation system 1 can determine whether to perform maintenance work on the heat exchanger 30 in consideration of the variation of disturbance factors. The estimation unit 11 may output the allowable range of variation of the coolant inlet temperature or the magnitude of the heat load as the performance of the heat exchanger 30. That is, the performance of the heat exchanger 30 may include the allowable range of variation of the coolant inlet temperature or the magnitude of the heat load. The narrower the allowable range of variation, the worse the performance of the heat exchanger 30.

[0078] As an example, when the magnitude of the heat load of the fluid to be cooled circulation system 60 is set to a constant value and the coolant inlet temperature is varied, the inlet temperature of the fluid to be cooled is calculated. FIG. 4 shows a graph representing the relationship between the assumed value of the coolant inlet temperature and the calculated value of the inlet temperature of the fluid to be cooled corresponding to the assumed value of the coolant inlet temperature when the heat transfer coefficients of the heat exchanger 30 are K1, K2, K3, and K4, respectively. The horizontal axis represents the assumed value of the coolant inlet temperature. The vertical axis represents the calculated value of the inlet temperature of the fluid to be cooled. It is assumed that the relationship K1 < K2 < K3 < K4 holds for the heat transfer coefficient of the heat exchanger 30.

[0079] When the magnitude of the heat load of the fluid to be cooled circulation system 60 is set to a constant value, the higher the coolant inlet temperature, the higher the inlet temperature of the fluid to be cooled. Further, since the magnitude of the heat load, that is, the amount of heat exchanged by the heat exchanger 30 is constant, the smaller the heat transfer coefficient of the heat exchanger 30, the greater the difference between the inlet temperature of the fluid to be cooled and the coolant inlet temperature. As a result, the smaller the heat transfer coefficient of the heat exchanger 30, the higher the inlet temperature of the fluid to be cooled.

[0080] On the vertical axis of the graph in FIG. 4, the inlet temperature of the fluid to be cooled, that is, the upper limit value of the temperature of the device 62 to be cooled, is displayed. The smaller the heat transfer coefficient of the heat exchanger 30, the more likely it is to exceed the upper limit value when the temperature of the device 62 to be cooled fluctuates in response to the fluctuation of the inlet temperature of the cooling fluid. That is, the smaller the heat transfer coefficient of the heat exchanger 30, the more deteriorated the performance of the heat exchanger 30.

[0081] As another example, when the inlet temperature of the cooling fluid is set to a constant value and the magnitude of the heat load of the fluid circulation system 60 to be cooled is varied, the inlet temperature of the fluid to be cooled is calculated. FIG. 5 shows a graph representing the relationship between the assumed values of the magnitude of the heat load and the calculated values of the inlet temperature of the fluid to be cooled when the heat transfer coefficients of the heat exchanger 30 are K1, K2, K3, and K4, respectively. The horizontal axis represents the assumed values of the magnitude of the heat load. The vertical axis represents the calculated values of the inlet temperature of the fluid to be cooled. It is assumed that the relationship K1 < K2 < K3 < K4 holds for the heat transfer coefficient of the heat exchanger 30.

[0082] When the inlet temperature of the cooling fluid is set to a constant value, the higher the magnitude of the heat load, the higher the inlet temperature of the fluid to be cooled. Also, the smaller the heat transfer coefficient of the heat exchanger 30, the greater the difference between the inlet temperature of the fluid to be cooled and the inlet temperature of the cooling fluid. And since the inlet temperature of the cooling fluid is constant, the inlet temperature of the fluid to be cooled becomes higher. That is, the smaller the heat transfer coefficient of the heat exchanger 30, the higher the inlet temperature of the fluid to be cooled.

[0083] On the vertical axis of the graph in FIG. 5, the inlet temperature of the fluid to be cooled, that is, the upper limit value of the temperature of the device 62 to be cooled, is displayed. The smaller the heat transfer coefficient of the heat exchanger 30, the more likely it is to exceed the upper limit value when the temperature of the device 62 to be cooled fluctuates in response to the fluctuation of the inlet temperature of the cooling fluid. That is, the smaller the heat transfer coefficient of the heat exchanger 30, the more deteriorated the performance of the heat exchanger 30.

[0084] As in the two examples described above, the estimation unit 11 can estimate the performance of the heat exchanger 30 by calculating the range in which the inlet temperature of the fluid to be cooled, that is, the temperature of the device 62 to be cooled, may fluctuate based on the calculated value of the heat transfer coefficient of the heat exchanger 30.

[0085] From the graphs of Figures 4 and 5 described above, the relationship between the heat transfer coefficient of the heat exchanger 30 and the inlet temperature of the cooled fluid can be derived as shown in Figure 6. The horizontal axis represents the heat transfer coefficient. The vertical axis represents the inlet temperature of the cooled fluid. The points shown as design specifications represent the relationship between the heat transfer coefficient and the inlet temperature of the cooled fluid when the performance of the heat exchanger 30 is performed according to the design specifications.

[0086] According to the graph in Figure 6, the smaller the heat transfer coefficient of heat exchanger 30, the higher the cooled fluid inlet temperature. In other words, there is a negative correlation between the heat transfer coefficient of heat exchanger 30 and the cooled fluid inlet temperature. Furthermore, the smaller the heat transfer coefficient of heat exchanger 30, the greater the change in the cooled fluid inlet temperature relative to the change in the heat transfer coefficient. In other words, the smaller the heat transfer coefficient of heat exchanger 30, the more rapid the rise in the cooled fluid inlet temperature.

[0087] As another example, the cooled fluid inlet temperature was calculated when both the cooling fluid inlet temperature and the magnitude of the heat load of the cooled fluid circulation system 60 were varied. FIG. 7 shows a two-dimensional map of the calculated cooled fluid inlet temperature when the heat transfer coefficient of the heat exchanger 30 was set to a constant value. The horizontal axis of the two-dimensional map in FIG. 7 represents the assumed value of the cooling fluid inlet temperature. The vertical axis represents the assumed value of the heat load. Each cell in the two-dimensional map represents the result of classifying the cooled fluid inlet temperature corresponding to the combination of the cooling fluid inlet temperature and the heat load into four categories: "low," "medium," "high," and ">upper limit." From the two-dimensional map in FIG. 7, a user of the heat exchanger performance estimation system 1 can easily recognize that the cooled fluid inlet temperature exceeds the upper limit when at least one of the cooling fluid inlet temperature and the heat load is high.

[0088] By representing the cooled fluid inlet temperature in this way using a two-dimensional map, it is possible to easily recognize the range in which the cooled fluid inlet temperature may fluctuate when both the cooling fluid inlet temperature and the magnitude of the heat load of the cooled fluid circulation system 60 are varied. As a result, it is easy to recognize whether the performance of the heat exchanger 30 has deteriorated. In this way, the two-dimensional map representing the cooled fluid inlet temperature when both the cooling fluid inlet temperature and the magnitude of the heat load of the cooled fluid circulation system 60 are varied is used as useful information for determining the need for maintenance work on the heat exchanger 30.

[0089] The representation of the cooled fluid inlet temperature using a two-dimensional map is not limited to the example shown in Fig. 7. Furthermore, the predicted value of the cooled fluid inlet temperature when both the cooling fluid inlet temperature and the magnitude of the heat load of the cooled fluid circulation system 60 are varied, i.e., the predicted temperature, may be displayed as data associated with the assumed values ​​of the cooling fluid inlet temperature and the heat load. The data associating the assumed values ​​of the cooling fluid inlet temperature and the heat load with the predicted temperature is not limited to a two-dimensional map, and may be expressed in the form of a three-dimensional graph or a table, for example. The data associating the assumed values ​​of the cooling fluid inlet temperature and the heat load with the predicted temperature may be output as maintenance information.

[0090] <Output of Estimated Performance of Heat Exchanger 30> In the heat exchanger performance estimation system 1, the output device 20 may display the estimation result of the performance of the heat exchanger 30 by the performance estimation device 10. For example, the output device 20 may cause the control unit 21 to generate the graph exemplified in FIG. 4 or FIG. 5 above as the estimation result of the performance of the heat exchanger 30, and display the generated graph on the display unit 24. Furthermore, the control unit 21 may generate the two-dimensional map exemplified in FIG. 7 above as the estimation result of the performance of the heat exchanger 30, and display the generated graph on the display unit 24.

[0091] When the predicted value of the cooled fluid inlet temperature, i.e., the predicted temperature, exceeds the upper temperature limit of the cooled fluid, the output device 20 may display that the performance of the heat exchanger 30 has deteriorated or that the heat exchanger 30 is abnormal. When the range in which the cooled fluid inlet temperature may fluctuate, i.e., the upper limit of the predicted temperature fluctuation range, exceeds the upper temperature limit of the cooled fluid, the output device 20 may output information notifying the user that the performance of the heat exchanger 30 has deteriorated or that the heat exchanger 30 is abnormal.

[0092] The output device 20 may output an alarm as information indicating that the performance of the heat exchanger 30 has deteriorated or that there is an abnormality in the heat exchanger 30. The alarm may be displayed on the display unit 24, or may be output as audio information from an audio output device.

[0093] The output device 20 may specifically display the predicted temperature or the predicted temperature fluctuation range as the performance of the heat exchanger 30 on the display unit 24. The output device 20 may display the assumed value of the cooling fluid inlet temperature or the heat load and the predicted temperature in the form of a two-dimensional map, a three-dimensional graph, or a table, in association with each other on the display unit 24.

[0094] The output device 20 may display on the display unit 24 a graph of the change over time in the heat transfer coefficient of the heat exchanger 30, as shown in Fig. 3. The user can determine the timing for performing maintenance work on the heat exchanger 30 by observing the tendency for the heat transfer coefficient to decrease. The output device 20 may plan the timing for performing maintenance work on the heat exchanger 30 or the details of the maintenance work based on the data on the change over time in the heat transfer coefficient of the heat exchanger 30, and notify the user of this as maintenance information.

[0095] <Example of procedure for estimating heat exchanger performance> The performance estimation device 10 may execute a performance estimation method including the steps of the flowcharts exemplified in Figures 8 and 9. The flowchart in Figure 8 includes a procedure for calculating the heat transfer coefficient of the heat exchanger 30. The flowchart in Figure 9 includes a procedure for predicting the cooled fluid inlet temperature when at least one of the cooling fluid inlet temperature or the magnitude of the heat load varies using the calculated heat transfer coefficient, and determining the performance of the heat exchanger 30. The performance estimation method may be realized as a performance estimation program executed by the estimation unit 11 of the performance estimation device 10 or the control unit 21 of the output device 20. The performance estimation program may be stored in a non-transitory computer-readable medium.

[0096] 8, estimation unit 11 of performance estimation device 10 acquires the cooled fluid inlet temperature from measurement device 40 (step S1). Estimation unit 11 acquires the cooled fluid outlet temperature from measurement device 40 (step S2). Estimation unit 11 acquires the cooled fluid flow rate from measurement device 40 (step S3). Estimation unit 11 calculates the amount of heat transferred from the cooled fluid, i.e., the amount of heat exchanged by heat exchanger 30, based on information about the cooled fluid (step S4).

[0097] The estimation unit 11 acquires the cooling fluid inlet temperature from the measurement device 40 (step S5). The estimation unit 11 acquires the cooling fluid outlet temperature from the measurement device 40 (step S6). The estimation unit 11 calculates the logarithmic mean temperature difference between the cooling fluid and the cooled fluid based on information about the temperatures of the cooling fluid and the cooled fluid (step S7).

[0098] The estimation unit 11 calculates the heat transfer coefficient of the heat exchanger 30 based on the heat transfer amount of the cooled fluid calculated in step S4 and the logarithmic mean temperature difference calculated in step S7 (step S8). After executing the procedure of step S8, the estimation unit 11 ends the execution of the flowchart in FIG.

[0099] The estimation unit 11 calculates the amount of heat transfer of the cooled fluid based on information about the cooled fluid in the procedure from steps S1 to S4, but may instead calculate the amount of heat transfer of the cooling fluid based on information about the cooling fluid.

[0100] 9, the estimation unit 11 acquires the value of the heat transfer coefficient calculated in the procedure of step S8 of the flowchart in Fig. 8 (step S11). The estimation unit 11 acquires upper and lower limit values ​​of the cooling fluid inlet temperature as a range within which the cooling fluid inlet temperature may fluctuate (step S12). The estimation unit 11 acquires upper and lower limit values ​​of the magnitude of the heat load as a range within which the magnitude of the heat load may fluctuate (step S13).

[0101] The estimation unit 11 acquires the amount of heat transfer of the cooled fluid calculated in step S4 of the flowchart in FIG. 8, i.e., the amount of heat exchanged by the heat exchanger 30, as a measured value of the thermal load (step S14). The amount of heat transfer of the cooled fluid, i.e., the amount of heat exchanged by the heat exchanger 30, is calculated based on the measured value of the cooled fluid. Therefore, the calculated value of the amount of heat exchanged by the heat exchanger 30 may be regarded as a measured value. As described above, from the viewpoint of the heat balance between the cooling fluid circulation system 50 and the cooled fluid circulation system 60, it may be assumed that the magnitude of the thermal load of the cooled fluid circulation system 60 matches the amount of heat exchanged by the heat exchanger 30. Therefore, the measured value of the amount of heat exchanged by the heat exchanger 30 may be regarded as a measured value of the magnitude of the thermal load.

[0102] The estimation unit 11 sets the measured value of the current heat load magnitude acquired in step S14 as the assumed value of the heat load magnitude, and predicts the cooled fluid inlet temperature when the cooling fluid inlet temperature fluctuates (step S15). That is, the estimation unit 11 predicts a range in which the cooled fluid inlet temperature may fluctuate in response to fluctuations in the cooling fluid inlet temperature.

[0103] The estimation unit 11 acquires the measured value of the cooling fluid inlet temperature (step S16).

[0104] The estimation unit 11 sets the current measured value of the cooling fluid inlet temperature acquired in step S16 as the assumed value of the cooling fluid inlet temperature, and predicts the cooled fluid inlet temperature when the magnitude of the heat load fluctuates (step S17). In other words, the estimation unit 11 predicts a range in which the cooled fluid inlet temperature may fluctuate depending on the magnitude of the heat load.

[0105] The control unit 21 of the output device 20 generates maintenance information based on the results of the predictions made in the procedures of steps S15 and S17, and displays the maintenance information on the display unit 24 (step S18).

[0106] The control unit 21 determines whether the range in which the cooled fluid inlet temperature may fluctuate is greater than the set upper limit value of the cooled fluid inlet temperature (step S19). If the range in which the cooled fluid inlet temperature may fluctuate is greater than the set upper limit value of the cooled fluid inlet temperature (step S19: YES), the control unit 21 determines that the performance of the heat exchanger 30 has deteriorated and notifies the user that the condition of the heat exchanger 30 is abnormal (step S20). The control unit 21 may display a notification to the user on the display unit 24. After executing the procedure of step S20, the control unit 21 ends execution of the flowchart of FIG. 9.

[0107] If the range in which the cooled fluid inlet temperature may fluctuate is not greater than the set upper limit value of the cooled fluid inlet temperature (step S19: NO), that is, if the range in which the cooled fluid inlet temperature may fluctuate is equal to or less than the set upper limit value of the cooled fluid inlet temperature, the control unit 21 terminates execution of the flowchart of Figure 9 without executing the abnormality notification procedure of step S20.

[0108] The estimation unit 11 of the performance estimation device 10 may switch the order of executing the procedure for predicting the cooled fluid inlet temperature when the cooling fluid inlet temperature fluctuates in step S15 of the flowchart in Fig. 9 and the procedure for predicting the cooled fluid inlet temperature when the magnitude of the heat load fluctuates in step S17. The estimation unit 11 may predict the cooled fluid inlet temperature when both the cooling fluid inlet temperature and the magnitude of the heat load fluctuate.

[0109] (summary) As described above, in the heat exchanger performance estimation system 1 according to the present disclosure, the performance estimation device 10 calculates the heat transfer coefficient by a simple calculation based on actual measurement data of the cooling fluid and the cooled fluid. Based on the calculated heat transfer coefficient, the performance estimation device 10 predicts the temperature of the cooled fluid in response to changes in external factors such as the cooling fluid inlet temperature or the magnitude of the heat load. The performance estimation device 10 can easily estimate the performance of the heat exchanger 30 by comparing the predicted temperature of the cooled fluid, i.e., the temperature of the cooled device 62, with a set threshold, i.e., a set upper limit value.

[0110] Furthermore, the output device 20 can output the estimated performance results of the heat exchanger 30 as information useful for maintaining the heat exchanger 30, i.e., maintenance information. By properly performing maintenance of the heat exchanger 30 based on the maintenance information, the temperature of the cooled device 62 in the cooled fluid circulation system 60 to which the heat exchanger 30 is connected is properly controlled. By properly controlling the temperature of the cooled device 62, a situation in which the cooled device 62 stops operating due to a temperature rise is avoided. As a result, the availability rate of the production line equipped with the cooled device 62 is improved.

[0111] As described above, the output device 20 may generate and output maintenance information for the heat exchanger 30 based on the estimation result of the performance of the heat exchanger 30. The output device 20 may acquire the maintenance information for the heat exchanger 30 from the performance estimation device 10 and execute only the output of the maintenance information for the heat exchanger 30. When the output device 20 generates the maintenance information for the heat exchanger 30, the performance estimation device 10 may output only the estimation result of the performance of the heat exchanger 30 without generating the maintenance information for the heat exchanger 30.

[0112] Although the embodiments of the present disclosure have been described based on the drawings and examples, it should be noted that those skilled in the art could make various modifications or alterations based on the present disclosure. Therefore, it should be noted that these modifications and alterations are included within the scope of the present disclosure. For example, the functions included in each component or step can be rearranged so as not to cause logical inconsistencies, and multiple components or steps can be combined or divided into one. The embodiments of the present disclosure can also be realized as a program executed by a processor included in an apparatus or a storage medium on which a program is recorded. It should be understood that these are also included within the scope of the present disclosure. [Explanation of symbols]

[0113] 1. Heat exchanger performance estimation system 10 Performance estimation device (11: Estimation unit, 12: Storage unit, 13: Communication unit) 20 output device (21: control unit, 22: memory unit, 23: communication unit, 24: display unit) 30 heat exchanger 40 Measuring Equipment 50 Cooling fluid circulation system 60 Cooled fluid circulation system (62: cooled device, 64: tank, 66: pump)

Claims

1. 1. A method for estimating the performance of a heat exchanger that transfers heat from a cooled fluid to a cooling fluid circulating in a system including a heat load, comprising: Calculating a heat transfer coefficient from the cooled fluid to the cooling fluid based on a cooled fluid inlet temperature, which is the temperature of the cooled fluid when it enters the heat exchanger, a cooled fluid outlet temperature, which is the temperature of the cooled fluid when it leaves the heat exchanger, a flow rate of the cooled fluid, a cooling fluid inlet temperature, which is the temperature of the cooling fluid when it enters the heat exchanger, a cooling fluid outlet temperature, which is the temperature of the cooling fluid when it leaves the heat exchanger, and a flow rate of the cooling fluid; Assuming that at least one of the cooling fluid inlet temperature and the heat load is varied, calculating a predicted temperature that is a predicted value of the cooled fluid inlet temperature based on an assumed value of at least one of the cooling fluid inlet temperature and the heat load; estimating performance of the heat exchanger based on the predicted temperature; and A method for estimating heat exchanger performance, comprising:

2. 2. The heat exchanger performance estimation method according to claim 1, further comprising estimating, as the performance of the heat exchanger, at least one of the range of the cooling fluid inlet temperature or the range of the heat load required for the cooled fluid inlet temperature to be equal to or lower than an upper temperature limit value of the cooled fluid.

3. a performance estimation device that estimates the performance of the heat exchanger by executing the heat exchanger performance estimation method according to claim 1 or 2; an output device that outputs the estimated performance of the heat exchanger; A heat exchanger performance estimation system comprising:

4. The output device is displaying the predicted temperature when at least one of the cooling fluid inlet temperature or the heat load is changed; If the predicted temperature exceeds an upper temperature limit of the cooled fluid, an abnormality is displayed in the heat exchanger. The heat exchanger performance estimation system according to claim 3 .

5. a communication unit that acquires an estimated result of the performance of the heat exchanger from a performance estimation device that executes the heat exchanger performance estimation method according to claim 1 or 2; a display unit that displays the estimated performance of the heat exchanger; An output device comprising:

6. 6. The output device according to claim 5, wherein the display unit displays, as an estimation result of the performance of the heat exchanger, an assumed value of at least one of the cooling fluid inlet temperature and the heat load in association with the predicted temperature.

7. The output device according to claim 6 , wherein the display unit displays the assumed value of the cooling fluid inlet temperature, the assumed value of the heat load, and the predicted temperature in the form of a two-dimensional map, a three-dimensional graph, or a table in association with each other.

8. The output device according to claim 5 , wherein the display unit displays the predicted temperature when it is assumed that at least one of the cooling fluid inlet temperature and the heat load has changed.

9. The output device according to claim 8 , wherein the display unit displays that the heat exchanger is abnormal when the predicted temperature exceeds an upper temperature limit value of the cooled fluid.

Images