Ultrasonic calorimeter, miswiring detection method, and miswiring detection program

Abstract

To provide an ultrasonic calorimeter in which erroneous wiring can be recognized easily even when a feed temperature sensor and a return temperature sensor are wired alternately (teleco wiring) by mistake.SOLUTION: The calculation unit 120 includes a miswiring detection unit, and the miswiring detection unit is configured to calculate a sound speed calculation temperature T2 ' based on a sound speed calculated by the ultrasonic flow meter 110 based on a ToF (TimeofFlight), and the calculation unit 120 is configured to calculate a supplied heat quantity or an absorbed heat quantity. 110, the temperature measured by the sensor connected to the first interface IF1 or the temperature measured by the sensor connected to the second interface IF2 is compared with the sound velocity calculation temperature T2 ', and the presence or absence of miswiring is detected based on the comparison result.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an ultrasonic calorimeter, a wiring error detection method, and a wiring error detection program. [Background technology]

[0002] An ultrasonic calorimeter is known that combines an ultrasonic flow meter (also called an "ultrasonic flow meter") with at least two temperature sensors. For example, Patent Document 1 (see especially FIG. 5) discloses an ultrasonic calorimeter that measures the amount of heat supplied to a fan coil unit (load).

[0003] The ultrasonic calorimeter disclosed in Patent Document 1 includes an ultrasonic flowmeter that measures the flow rate of chilled or hot water flowing through a fan coil unit, a temperature sensor that detects the temperature of the chilled or hot water to the fan coil unit (the temperature of the supply water), and another temperature sensor that detects the temperature of the chilled or hot water returned from the fan coil unit (the temperature of the return water).The ultrasonic calorimeter disclosed in Patent Document 1 calculates the amount of heat supplied to the fan coil unit (or the amount of heat absorbed from the fan coil unit) based on the measured flow rate and the detected temperatures of the supply water and return water. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-178127 Summary of the Invention [Problem to be solved by the invention]

[0005] An ultrasonic calorimeter has a pair of temperature sensors, one for the feed water (for forward water) and one for the return water (for return water). At the site where the ultrasonic calorimeter is installed, it is necessary to wire the feed water temperature sensor and the return water temperature sensor, but there has been a problem of incorrect wiring of the feed water temperature sensor and the return water temperature sensor. A specific cause of incorrect wiring is thought to be, for example, that the pipes may be wrapped in insulation, making it difficult to determine the flow direction of the liquid flowing through the pipes. Another possible cause is that when working at high altitudes or in narrow spaces, it is difficult to correctly distinguish between the feed cable and the return cable.

[0006] The disclosed technology aims to solve the above-mentioned problem and provide an ultrasonic calorimeter that can easily recognize incorrect wiring even if the wiring of the feed temperature sensor and the return temperature sensor is mistakenly wired alternately (teleco wiring). [Means for solving the problem]

[0007] The ultrasonic calorimeter according to the disclosed technology includes an ultrasonic flow meter that measures the flow rate of a fluid and a calculation unit that calculates the amount of heat supplied or absorbed, and the calculation unit includes a miswiring detection unit that calculates a speed-of-sound calculated temperature T2' based on the speed of sound calculated by the ultrasonic flow meter based on ToF (Time of Flight), compares the temperature measured by a sensor connected to the first interface or the temperature measured by a sensor connected to the second interface with the speed-of-sound calculated temperature T2', and detects the presence or absence of miswiring based on the comparison result. [Effects of the Invention]

[0008] Due to the above technical features, the ultrasonic calorimeter according to the disclosed technology has the effect of easily recognizing incorrect wiring even if the wiring of the sending temperature sensor and the returning temperature sensor is mistakenly performed using a telecommunications cable. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is an explanatory diagram showing an example of use of an ultrasonic calorimeter 100 according to the first embodiment. [Figure 2] FIG. 2 is an explanatory diagram showing the ultrasonic calorimeter 100 according to the first embodiment when wired correctly. [Figure 3] FIG. 3 is an explanatory diagram showing a case where the ultrasonic calorimeter 100 according to the first embodiment is erroneously wired. [Figure 4] FIG. 4 is a block diagram showing the functional configuration of the calculation unit 120 of the ultrasonic calorimeter 100 according to the first embodiment. [Figure 5] FIG. 5 is a flowchart showing a processing flow of the faulty wiring detection method according to the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Embodiment 1 Fig. 1 is an explanatory diagram showing an example of use of an ultrasonic calorimeter 100 according to embodiment 1. As shown in Fig. 1, the ultrasonic calorimeter 100 according to embodiment 1 includes an ultrasonic flowmeter 110, a calculation unit 120, a first sensor S1, a second sensor S2, a first interface IF1, and a second interface IF2. The ultrasonic calorimeter 100 is installed to calculate the amount of heat supplied to the heat load 300 .

[0011] <<Ultrasonic flow meter 110 constituting ultrasonic calorimeter 100>> The ultrasonic flow meter 110 constituting the ultrasonic calorimeter 100 is a component that measures the flow rate of a fluid using ultrasonic waves. The ultrasonic flow meter 110 constituting the ultrasonic calorimeter 100 may be, for example, the ultrasonic flow meter disclosed in Patent Document 1. As shown in FIG. 1 , in this specification, the ultrasonic flow meter 110 is assumed to be installed so as to measure the flow rate of return water returning from the heat load 300. Generally, ultrasonic flow meters include a Doppler type and a transit time type. The ultrasonic flow meter 110 according to the present disclosure may be either a Doppler type or a transit time type. 1, the ultrasonic wave propagation path is represented as a so-called V-shape in which the ultrasonic wave is reflected once by the pipe wall, but the technology disclosed herein is not limited to this. The ultrasonic wave propagation path adopted by the ultrasonic flowmeter 110 according to the technology disclosed herein may be designed to be linear so that the ultrasonic wave does not reflect once by the pipe wall, or may be designed so that the ultrasonic wave reflects twice or more by the pipe wall. Furthermore, the ultrasonic flowmeter 110 according to the technology disclosed herein may adopt multiple ultrasonic wave propagation paths (for example, two axial paths and four swirl paths, etc.) to increase the amount of information that can be obtained. The ultrasonic flowmeter 110 according to the disclosed technique may be one in which the ultrasonic vibrator and ultrasonic sensor (for example, a piezoelectric element) are in direct contact with the fluid to be measured, or may be a clamp-on type that measures from outside the piping.

[0012] <<Calculation unit 120 constituting ultrasonic calorimeter 100>> The calculation unit 120 constituting the ultrasonic calorimeter 100 is, simply put, a component that calculates the amount of heat supplied to the heat load 300 or the amount of heat absorbed from the heat load 300 based on the flow rate measured by the ultrasonic flowmeter 110 and the temperatures of the supply water and the return water detected by a first sensor S1 and a second sensor S2, which will be described later. Details of the calculation unit 120 will become clear from the explanation given below.

[0013] First sensor S1 and second sensor S2 constituting ultrasonic calorimeter 100 The first sensor S1 is a temperature sensor that measures the temperature of the supply water to the thermal load 300. The second sensor S2 is a temperature sensor that measures the temperature of the return water returned from the thermal load 300. The first sensor S1 and the second sensor S2 may be, for example, thermocouples. The ultrasonic calorimeter 100 includes a first interface IF1 for the first sensor S1 and a second interface IF2 for the second sensor S2. When the first sensor S1 and the second sensor S2 are thermocouples, the first interface IF1 and the second sensor S2 are, for example, terminal blocks.

[0014] Fig. 2 is an explanatory diagram showing a case where wiring is correctly performed in the ultrasonic calorimeter 100 according to embodiment 1. As shown in Fig. 2, the ultrasonic calorimeter 100 is designed so that the wiring of the first sensor S1 is connected to the first interface IF1, and the wiring of the second sensor S2 is connected to the second interface IF2.

[0015] FIG. 3 is an explanatory diagram showing a case where the ultrasonic calorimeter 100 according to the first embodiment is erroneously wired. As described above, the ultrasonic calorimeter 100 includes a pair of temperature-sensing units, the first sensor S1 and the second sensor S2, for feeding (for forward water) and returning (for return water). At the site where the ultrasonic calorimeter 100 is installed, the first sensor S1 and the second sensor S2 need to be wired, but as shown in FIG. 3, there has been a problem of incorrect wiring of the first sensor S1 and the second sensor S2. A specific cause of incorrect wiring is thought to be, for example, that the pipes may be wrapped in insulation, making it difficult to determine the flow direction of the liquid flowing through the pipes. Another possible cause is that it is not easy to correctly distinguish between the feeding cable and the returning cable when working at high altitudes or in narrow spaces.

[0016] There is another factor that makes correct wiring difficult. That is, the ultrasonic calorimeter 100 is used in both cases: cooling the heat load 300 by flowing cold water through the pipes (cooling operation), and heating the heat load 300 by flowing hot water through the pipes (heating operation). In either case, the ultrasonic calorimeter 100 is designed to correctly output the value of the heat quantity exchanged in the heat load 300 with a positive or negative sign. Therefore, it is not possible to simply compare the voltage input to the first interface IF1 and the voltage input to the second interface IF2 and conclude that "the detected temperature on the sending side (first interface IF1) is lower than the detected temperature on the returning side (second interface IF2), so there is incorrect wiring." That is, even if the wiring of the first sensor S1 and the second sensor S2 is mistakenly connected to a tap, each of the first sensor S1 and the second sensor S2 will detect the water temperature normally, and the value itself output by the ultrasonic calorimeter 100 will not be an order of magnitude different, regardless of whether it is positive or negative. Therefore, it is difficult to discover the miswiring, which may even lead to problems such as incorrect billing.

[0017] 4 is a block diagram showing the functional configuration of the calculation unit 120 of the ultrasonic calorimeter 100 according to embodiment 1. As shown in FIG. 4, the calculation unit 120 of the ultrasonic calorimeter 100 includes a flow rate acquisition unit 122, a calorie calculation unit 124, and a faulty wiring detection unit 126.

[0018] <<Flow Rate Acquisition Unit 122 in Calculation Unit 120>> The flow rate acquisition unit 122 in the calculation unit 120 is a component that acquires the flow rate measured by the ultrasonic flowmeter 110.

[0019] <<Heat Quantity Calculation Unit 124 in Calculation Unit 120>> The heat quantity calculation unit 124 in the calculation unit 120 is a component that calculates the value of the heat quantity (with positive or negative sign) exchanged in the thermal load 300 based on the flow rate (Q) acquired by the flow rate acquisition unit 122 and the detected temperature of the supply water (hereinafter, "supply temperature T1") and the temperature of the return water (hereinafter, "return temperature T2"). Here, the flow rate acquisition unit 122 in the calculation unit 120 performs calculations assuming that the voltage input to the first interface IF1 corresponds to the supply temperature T1 and the voltage input to the second interface IF2 corresponds to the return temperature T2.

[0020] <<Error Wiring Detection Unit 126 in Calculation Unit 120>> Simply put, the faulty wiring detection unit 126 in the calculation unit 120 is a component that detects faulty wiring of the first sensor S1 and the second sensor S2. The mechanism by which the faulty wiring detection unit 126 detects faulty wiring will become clear from the explanation below.

[0021] 5 is a flowchart showing the processing flow of the miswiring detection method according to the first embodiment. As shown in FIG. 5, the processing flow of the miswiring detection method includes processing steps from ST1, which states "Measure the feed temperature T1," to ST7, which states "Issue a miswiring alarm." The processing steps shown in the flowchart of FIG. 5 are performed by the miswiring detection unit 126 in the calculation unit 120.

[0022] In the processing step (ST1) described as "Measure the sending temperature T1," the miswiring detection unit 126 calculates the sending temperature T1 based on the voltage input to the first interface IF1. Generally, there are standardized types of thermocouples (e.g., Type E, Type T, etc.), and the miswiring detection unit 126 may have a mathematical model or lookup table for calculating the temperature according to the types of the first sensor S1 and second sensor S2 used.

[0023] Similarly, in the processing step (ST2) described as "measure return temperature T2", the faulty wiring detection unit 126 calculates the return temperature T2 based on the voltage input to the second interface IF2.

[0024] In the processing step (ST3) described as "Measure sound speed calculated temperature T2'", the miswiring detection unit 126 calculates the sound speed (c) at which the ultrasonic waves propagate through the medium (liquid) inside the pipe in the ultrasonic flowmeter 110, and calculates the temperature of the return water (hereinafter referred to as "sound speed calculated temperature T2'") from the calculated sound speed (c). The faulty wiring detection unit 126 uses, for example, the following fifth-order polynomial (approximation) to calculate the sound speed calculation temperature T2'. TIFF2026000485000002.tif46166 However, to emphasize that the left side of the formula (1) is an estimated value based on a polynomial, the accent symbol "c" is added (hereinafter referred to as "c hat"). Also, T appearing on the right side of the formula (1) D is the temperature input to the polynomial model (1). D When you enter, the temperature of the medium becomes TD Outputs c hat, which is the estimated value of the sound speed in the medium when D This is a mathematical model from to c hat. Although a fifth-order polynomial is shown in Equation (1), the disclosed technology is not limited to this. The order of the polynomial used by the wiring error detection unit 126 may be selected appropriately depending on the specifications.

[0025] As mentioned above, equation (1) is T D Depending on the situation, a mathematical model that maps from the speed of sound to temperature may be separately prepared as a mathematical model used by the wiring error detection unit 126. Even when the faulty wiring detection unit 126 uses the formula (1), the temperature can be obtained from the speed of sound by using a numerical solution such as Newton's method. When formula (1) is used in the forward direction, the ultrasonic flowmeter 110 compares the sound velocity calculated from the ToF (Time of Flight) with the sound velocity (c) calculated from the voltage input to the second interface IF2 to detect whether there is a wiring error. When formula (1) is used in the reverse direction using a numerical solution, the sound velocity calculated temperature T2' calculated by the ultrasonic flowmeter 110 is compared with the return temperature T2 calculated from the voltage input to the second interface IF2 to detect whether there is a wiring error.

[0026] (Numerical example) The processing contents can be easily understood by applying specific numerical examples to ST4 to ST7 shown in the flowchart of FIG. Here, it is assumed that the delivery temperature T1 is 45° C. and the return temperature T2 is 40° C. Here, it is assumed that the temperature measurements by the first sensor S1 and the second sensor S2 are sufficiently accurate. Next, it is assumed that the speed of sound calculated from the ToF (Time of Flight) by the ultrasonic flowmeter 110 is 1529.2 [m / s]. The speed of sound (c) can be calculated from the ToF (Time of Flight) using the following simple formula: TIFF2026000485000003.tif12166 Here, L in Equation (2) is the propagation path length, and T is the ToF (Time of Flight), i.e., the time it takes for the ultrasonic wave to pass through the propagation path. For example, if the propagation length (L) is 65.53 [mm] and the ToF (Time of Flight) is 42.85 [μs], the speed of sound (c) is calculated to be 1529.2 [m / s] using Equation (2).

[0027] Using the approximate polynomial (1) in the reverse direction, we find T where c is 1529.2 [m / s]. D When calculated numerically, the following value is obtained: TIFF2026000485000004.tif9166 That is, the sound speed calculated temperature T2' is T D The temperature becomes 40.014°C, which is the value of (step ST3).

[0028] In a situation where the ultrasonic calorimeter 100 is used, the temperature of the supply water, i.e., the supply temperature T1, is usually known. In the example shown here, the supply temperature T1 is known to be around 45°C, and it is also known that the return temperature T2 is generally 4 to 6°C lower than the supply temperature T1. Therefore, in order to detect a situation in which the ultrasonic flowmeter 110 has been mistakenly installed in a pipe through which forward water flows, the incorrect wiring detection unit 126 sets the sound speed calculated temperature T2' to a threshold value ("T th ") (step ST4). In the numerical example shown here, the threshold value (T th) is, for example, 44°C. In the example shown here, the ultrasonic flowmeter 110 is correctly installed in the pipe through which return water flows, so the result in the process of ST4 is "NO." If the ultrasonic flowmeter 110 is mistakenly installed in the pipe through which forward water flows and the result in the process of ST4 is "YES," it is advisable to perform a process (not shown) that warns that the ultrasonic flowmeter 110 has been mistakenly installed in the pipe through which forward water flows.

[0029] If the result of the process in ST4 is "NO", the process proceeds to ST5. In processing step ST5, the faulty wiring detection unit 126 checks whether the temperature measured by the temperature sensor connected to the second interface IF2 is sufficiently close to the sound speed calculation temperature T2'. In this numerical example, as shown in Figure 2, if the first sensor S1 and the second sensor S2 are correctly wired to the first interface IF1 and the second interface IF2, the temperature measured by the temperature sensor connected to the second interface IF2 is detected as 40 [°C], which is confirmed to be a value sufficiently close to the sound speed calculation temperature T2', 40.014 [°C]. In this numerical example, as shown in Figure 3, if the first sensor S1 and the second sensor S2 are mistakenly wired to the first interface IF1 and the second interface IF2 (in the case of so-called teleco wiring), the temperature measured by the temperature sensor connected to the second interface IF2 is detected as 45 [°C], which is a value far from the sound speed calculation temperature T2', which is 40.014 [°C]. The threshold value for the absolute value of the difference between T2 and T2' used in ST4 (ΔT th ) is set to, for example, 1 [°C]. Note that the specific threshold value may be determined appropriately depending on the specifications.

[0030] If the result of the processing in ST5 is "YES," that is, if the absolute value of the difference between the temperature measured by the temperature sensor connected to the second interface IF2 and the sound speed calculation temperature T2' is equal to or greater than the threshold value (ΔT th) In the above cases, this alone makes it highly likely that the wiring is incorrect. However, the faulty wiring detection method according to the disclosed technique may further include the determination process shown in ST6.

[0031] In processing step ST6, the faulty wiring detection unit 126 checks whether the temperature measured by the temperature sensor connected to the first interface IF1 is a value sufficiently different from the sound speed calculation temperature T2'. In this numerical example, as shown in Figure 2, if the first sensor S1 and the second sensor S2 are correctly wired to the first interface IF1 and the second interface IF2, the temperature measured by the temperature sensor connected to the first interface IF1 is detected as 45 [°C], which is confirmed to be a value sufficiently different from the sound speed calculation temperature T2', which is 40.014 [°C]. In this numerical example, as shown in Figure 3, if the first sensor S1 and the second sensor S2 are mistakenly wired to the first interface IF1 and the second interface IF2 (in the case of so-called teleco wiring), the temperature measured by the temperature sensor connected to the first interface IF1 will be detected as 40 [°C], which is not far from the sound speed calculation temperature T2', which is 40.014 [°C]. The threshold value for the absolute value of the difference between T1 and T2' used in ST6 (ΔT th ) may be the same as the threshold value used in ST5, or may be a separately set value. As with the threshold value used in ST5, the value of the ST6 threshold may be determined appropriately according to the specifications.

[0032] If the result of the processing in ST6 is "YES," that is, if the absolute value of the difference between the temperature measured by the temperature sensor connected to the first interface IF1 and the sound speed calculation temperature T2' is equal to or greater than the threshold value (ΔT th In the following cases, the faulty wiring detection unit 126 executes a process of issuing an alarm indicating faulty wiring (step ST7). A possible method for warning of incorrect wiring is to flash or light up a yellow or red LED, for example.

[0033] One embodiment of the ultrasonic calorimeter according to the disclosed technology includes an ultrasonic flowmeter 110 that measures the flow rate of a fluid, and a calculation unit 120 that calculates the amount of heat supplied or absorbed, the calculation unit 120 including a miswiring detection unit 126 that calculates a speed-of-sound calculated temperature T2' based on the speed of sound calculated by the ultrasonic flowmeter 110 based on ToF (Time of Flight), compares the temperature measured by the sensor connected to the first interface IF1 or the temperature measured by the sensor connected to the second interface IF2 with the speed-of-sound calculated temperature T2', and detects the presence or absence of miswiring based on the comparison result. Because of these technical features, the ultrasonic calorimeter according to the disclosed technology has the effect of easily recognizing incorrect wiring even if the first sensor S1 and the second sensor S2 are mistakenly wired to the first interface IF1 and the second interface IF2 at the site where the ultrasonic calorimeter 100 is installed.

[0034] One embodiment of the miswiring detection method according to the disclosed technology is a miswiring detection method for an ultrasonic calorimeter including an ultrasonic flowmeter 110 that measures the flow rate of a fluid and a calculation unit 120 that calculates the amount of heat supplied or absorbed, in which a miswiring detection unit 126 included in the calculation unit 120 calculates a speed-of-sound calculated temperature T2' based on the speed of sound calculated by the ultrasonic flowmeter 110 based on ToF (Time of Flight), compares the temperature measured by a sensor connected to the first interface IF1 or the temperature measured by a sensor connected to the second interface IF2 with the speed-of-sound calculated temperature T2', and detects the presence or absence of miswiring based on the comparison result. Due to these technical features, the miswiring detection method according to the disclosed technology has the effect of easily recognizing miswiring even if the first sensor S1 and the second sensor S2 are mistakenly connected to the first interface IF1 and the second interface IF2 via telecommunications at the site where the ultrasonic calorimeter 100 is installed.

[0035] One embodiment of the wiring error detection program according to the disclosed technique is realized as a program for causing a computer to execute the wiring error detection method according to the disclosed technique. The computer referred to here is, for example, a processing circuit built into the ultrasonic calorimeter 100 , which realizes the functions and actions of the calculation unit 120 . [Industrial Applicability]

[0036] The disclosed technology is applicable to an ultrasonic flowmeter that measures the flow rate of a fluid using ultrasonic waves and an ultrasonic calorimeter that uses this ultrasonic flowmeter, and has industrial applicability. [Explanation of symbols]

[0037] 100 ultrasonic calorimeter, 110 ultrasonic flow meter, 120 calculation unit, 122 flow rate acquisition unit, 124 heat quantity calculation unit, 126 faulty wiring detection unit, 300 heat load, IF1 first interface, IF2 second interface, S1 first sensor, S2 second sensor.

Claims

1. an ultrasonic flow meter for measuring the flow rate of a fluid; a calculation unit that calculates the amount of heat supplied or the amount of heat absorbed, the calculation unit includes a faulty wiring detection unit, The faulty wiring detection unit Based on the sound velocity calculated by the ultrasonic flowmeter based on the time of flight, the sound velocity calculated temperature T ２ ' is calculated, The temperature measured by the sensor connected to the first interface or the temperature measured by the sensor connected to the second interface and the sound speed calculation temperature T ２ Compare with Based on the comparison results, it detects whether there are any wiring errors. Ultrasonic calorimeter.

2. A method for detecting miswiring of an ultrasonic calorimeter including an ultrasonic flow meter that measures a flow rate of a fluid and a calculation unit that calculates a supplied heat amount or an absorbed heat amount, a faulty wiring detection unit included in the calculation unit, Based on the sound velocity calculated by the ultrasonic flowmeter based on the time of flight, the sound velocity calculated temperature T ２ ' is calculated, The temperature measured by the sensor connected to the first interface or the temperature measured by the sensor connected to the second interface and the sound speed calculation temperature T ２ Compare with Based on the comparison results, it detects whether there are any wiring errors. Miswiring detection method.

3. A faulty wiring detection program for causing a computer to execute the method according to claim 2.

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