Physical quantity measurement system, physical quantity measurement method, program, and integration system

Abstract

The present disclosure addresses the problem of reducing error when estimating the pressure loss of a mixed gas inside a flow path. A physical quantity measurement system (1) comprises: a flow path, through which a mixed gas flows; and an estimation unit (206). The estimation unit (206) estimates the pressure loss inside the flow path. The estimation unit (206) estimates pressure loss using the Reynolds number, the flow velocity of the mixed gas, the viscosity of the mixed gas, the viscosity of a reference gas, and the pressure of the mixed gas.

Description

Physical quantity measurement system, physical quantity measurement method, program, and integrated system

[0001] The present disclosure generally relates to a physical quantity measurement system, a physical quantity measurement method, a program, and an integrated system. More specifically, the present disclosure relates to a physical quantity measurement system including a flow path through which a mixed gas flows, and a physical quantity measurement method, a program, and an integrated system used in the physical quantity measurement system.

[0002] 2. Description of the Related Art Conventionally, a system for estimating pressure loss in a fluid supply passage through which a fluid (gas mixture) flows is known (see, for example, Patent Document 1).

[0003] Japanese Patent Laid-Open No. 2003-144999 describes estimating the pressure loss of a fluid based on the flow rate of the fluid detected by a flow rate detection unit.

[0004] When estimating the pressure loss of a fluid according to the flow rate of the fluid, a large error may occur due to fluctuations in the pressure of the fluid, etc.

[0005] International Publication No. 2016 / 013320

[0006] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a physical quantity measurement system, a physical quantity measurement method, a program, and an integrated system that can reduce errors when estimating pressure loss of a mixed gas inside a flow path.

[0007] A physical quantity measuring system according to an aspect of the present disclosure includes a flow path through which a gas mixture flows, and an estimator that estimates a pressure loss within the flow path using a Reynolds number, a flow velocity of the gas mixture, a viscosity of the gas mixture, a viscosity of a reference gas, and a pressure of the gas mixture.

[0008] A physical quantity measurement method according to one aspect of the present disclosure is used in a physical quantity measurement system including a flow path through which a mixed gas flows. The physical quantity measurement method includes an estimation step of estimating a pressure loss inside the flow path. In the estimation step, the pressure loss is estimated using a Reynolds number, a flow velocity of the mixed gas, a viscosity of the mixed gas, a viscosity of a reference gas, and a pressure of the mixed gas.

[0009] A program according to one aspect of the present disclosure is a program for causing a computer system to execute the physical quantity measuring method.

[0010] An integrated system according to one aspect of the present disclosure includes the physical quantity measurement system and a fuel cell system, wherein the physical quantity measurement system estimates the pressure loss of the mixed gas flowing in from the fuel cell system.

[0011] FIG. 1 is a block diagram showing the configuration of a physical quantity measurement system according to an embodiment. FIG. 2 is a system diagram showing the configuration of the physical quantity measurement system according to the embodiment. FIG. 3 is a cross-sectional view in the X-Y plane of a flow path main body provided in the physical quantity measurement system according to the embodiment. FIG. 4 is a graph illustrating a method for calculating a flow coefficient. FIG. 5 is a flowchart showing the operation of the physical quantity measurement system according to the embodiment. FIG. 6 is a flowchart showing a concentration measurement process performed by the physical quantity measurement system according to the embodiment. FIG. 7 is a flowchart showing a sound speed calculation process performed in the concentration measurement process according to the embodiment. FIG. 8 is a flowchart showing a concentration calculation process performed in the concentration measurement process according to the embodiment. FIG. 9 is a flowchart showing a flow rate measurement process performed by the physical quantity measurement system according to the embodiment. FIG. 10 is a flowchart showing a flow rate coefficient calculation process performed in the flow rate measurement process according to the embodiment. FIG. 11 is a flowchart showing a pressure loss estimation process performed by the physical quantity measurement system according to the embodiment. FIG. 12 is a system diagram showing the configuration of a physical quantity measurement system according to a first modification.

[0012] The embodiments and modifications described below are merely examples of the present disclosure, and the present disclosure is not limited to the embodiments and modifications. Various modifications other than the following embodiments and modifications are possible depending on the design, etc., as long as they do not deviate from the technical concept of the present disclosure.

[0013] (Embodiment) Hereinafter, a physical quantity measuring system 1 according to this embodiment will be described with reference to FIGS.

[0014] (1) Overview The physical quantity measurement system 1 of this embodiment is a system that measures the concentration of at least one gas contained in a gas mixture containing multiple gases flowing through a flow path 101 (see FIG. 3 ). For example, a gas mixture containing hydrogen, nitrogen, and water vapor flows through the flow path 101. The physical quantity measurement system 1 of this embodiment is used in a fuel cell system 2 (see FIG. 1 ). The fuel cell system 2 is a system that generates electricity using, for example, hydrogen and oxygen. The physical quantity measurement system 1 measures the flow rate of the gas mixture containing water vapor generated during power generation in the fuel cell system 2, measures the concentration of the gas contained in the gas mixture, and estimates the pressure loss of the gas mixture. That is, the physical quantity measurement system 1 estimates the pressure loss of the gas mixture flowing in from the fuel cell system 2. Furthermore, the physical quantity measurement system 1 measures the flow rate of the gas mixture, measures the concentration of the gas contained in the gas mixture, and estimates the pressure loss of the gas mixture. The physical quantity measurement system 1 and the fuel cell system 2 are provided in an integrated system 1000. In other words, the integrated system 1000 includes a physical quantity measuring system 1 and a fuel cell system 2 (see FIG. 1).

[0015] 1 and 3 , the physical quantity measuring system 1 of this embodiment includes a flow path 101 through which a mixed gas containing water vapor flows, and an estimation unit 206. The estimation unit 206 estimates a pressure loss inside the flow path 101. The estimation unit 206 estimates the pressure loss using the Reynolds number, the flow velocity of the mixed gas, the viscosity of the mixed gas, the viscosity of a reference gas, and the pressure of the mixed gas.

[0016] According to this configuration, the pressure loss is estimated using a value that is converted depending on the environment of the flow path through which the mixed gas flows, such as the pressure of the mixed gas, so that errors can be reduced.

[0017] (2) Configuration The detailed configuration of the physical quantity measuring system 1 will be described below with reference to FIGS. 1 to 3. FIG.

[0018] As shown in Fig. 1, the physical quantity measurement system 1 includes a flow path main body 10 and a processing device 20. The physical quantity measurement system 1 measures, as physical quantities, the concentration of hydrogen (hydrogen concentration) contained in a mixed gas flowing through the flow path main body 10, the flow rate of the mixed gas, and relative humidity. Furthermore, the physical quantity measurement system 1 measures, as physical quantities, the concentration of water vapor (water vapor concentration), the concentration of hydrogen (hydrogen concentration), and the flow rate of the mixed gas. The physical quantity measurement system 1 also estimates (measures) the pressure loss inside the flow path 101 as a physical quantity. Here, the concentrations (water vapor concentration, hydrogen concentration) measured by the physical quantity measurement system 1 are, for example, volume concentrations.

[0019] An X-axis, a Y-axis, and a Z-axis are defined for the flow path body 10 (see FIG. 2). The X-axis is an axis along the longitudinal direction of the flow path body 10, i.e., an axis along the direction in which the mixed gas flows. The Y-axis is an axis perpendicular to the X-axis, for example, an axis along the depth direction of the flow path body 10. The Z-axis is an axis perpendicular to both the X-axis and the Y-axis, for example, an axis along the height direction of the flow path body 10. FIG. 3 is a cross-sectional view of the flow path body 10 in a plane defined by the X-axis and the Y-axis (X-Y plane). Note that in FIG. 3, the pair of ultrasonic transmitter-receivers 11, 12 and the temperature sensor 14 are not shown in cross section.

[0020] (2.1) Flow Channel Main Body A mixed gas containing hydrogen, nitrogen, and water vapor flows through the flow channel main body 10. As shown in Fig. 1, the flow channel main body 10 has a pair of ultrasonic transmitters / receivers 11, 12, a pressure sensor 13, a temperature sensor 14, and a humidity sensor 15. Furthermore, as shown in Fig. 2, the flow channel main body 10 has a main body portion 100. In the following description, the ultrasonic transmitter / receiver 11 may be referred to as the first ultrasonic transmitter / receiver 11, and the ultrasonic transmitter / receiver 12 may be referred to as the second ultrasonic transmitter / receiver 12.

[0021] The main body 100 is formed in a substantially rectangular shape. A flow path 101 through which a fluid to be measured (a mixed gas), such as a mixed gas containing hydrogen, flows is formed in the center of the main body 100 (see FIG. 3 ). A first opening 110 and a second opening 111 are provided at both ends in the longitudinal direction of the main body 100. Specifically, the first opening 110 and the second opening 111 are provided on both side surfaces of the main body 100 that face each other in the longitudinal direction. The first opening 110 and the second opening 111 are connected by the flow path 101. The mixed gas flows in through the first opening 110, passes through the flow path 101, and flows out from the second opening 111.

[0022] The pair of ultrasonic transmitters / receivers 11, 12 transmit and receive ultrasonic waves. The pair of ultrasonic transmitters / receivers 11, 12 are arranged so that the ultrasonic waves cross the flow of the mixed gas in the flow channel 101. Specifically, the first ultrasonic transmitter / receiver 11 transmits (transmits) ultrasonic waves toward the second ultrasonic transmitter / receiver 12. The first ultrasonic transmitter / receiver 11 receives (receives) ultrasonic waves transmitted from the second ultrasonic transmitter / receiver 12. The second ultrasonic transmitter / receiver 12 transmits (transmits) ultrasonic waves toward the first ultrasonic transmitter / receiver 11. The second ultrasonic transmitter / receiver 12 receives (receives) ultrasonic waves transmitted from the first ultrasonic transmitter / receiver 11. The first ultrasonic transmitter / receiver 11 and the second ultrasonic transmitter / receiver 12 are arranged upstream and downstream at both ends of the shorter side of the flow channel 101 so that the ultrasonic signals cross the flow of the mixed gas. The first ultrasonic transmitter / receiver 11 and the second ultrasonic transmitter / receiver 12 are arranged upstream and downstream on opposing sides of the flow path 101 in the short direction so that ultrasonic signals cross the flow of the mixed gas. Specifically, the first ultrasonic transmitter / receiver 11 is arranged upstream and the second ultrasonic transmitter / receiver 12 is arranged downstream so as to face each other (see FIGS. 2 and 3). An ultrasonic propagation path 106 that propagates ultrasonic waves is formed in the opposing direction between the first ultrasonic transmitter / receiver 11 and the second ultrasonic transmitter / receiver 12 (see FIG. 3). The ultrasonic propagation path 106 is inclined at an angle θ with respect to the flow path 101 (see FIG. 3).

[0023] The pressure sensor 13 measures the pressure of the mixed gas flowing through the flow path 101 .

[0024] The temperature sensor 14 is, for example, a thermocouple, and measures the temperature of the gas mixture flowing through the flow path 101.

[0025] The humidity sensor 15 measures the humidity of the mixed gas flowing through the flow path 101 .

[0026] (2.2) Processing Device As shown in FIG. 1 , the processing device 20 includes a first communication unit 21 , a second communication unit 22 , a third communication unit 23 , a storage unit 24 , and a control unit 25 .

[0027] The processing device 20 includes, for example, a computer system having one or more processors and a memory. The processor executes a program stored in the memory, causing the computer system to function as the control unit 25. The program executed by the processor is pre-recorded in the memory of the computer system here, but may also be provided by being recorded on a non-transitory recording medium such as a memory card, or via a telecommunications line such as the Internet.

[0028] The first communication unit 21 is a communication interface for communicating with the first ultrasonic transmitter / receiver 11 and the second ultrasonic transmitter / receiver 12. The second communication unit 22 is a communication interface for communicating with the pressure sensor 13, the temperature sensor 14, and the humidity sensor 15. The third communication unit 23 is a communication interface for communicating with the fuel cell system 2 and a user device (not shown). The user device has a display unit such as a liquid crystal display, and is a device for notifying a user of measurement results and the like in the physical quantity measurement system 1. The third communication unit 23 notifies the fuel cell system 2 of the flow rate of the hydrogen-containing mixed gas, the concentration of gases contained in the mixed gas, and the estimated pressure loss.

[0029] The storage unit 24 is configured by a device selected from a read-only memory (ROM), a random access memory (RAM), an electrically erasable programmable read-only memory (EEPROM), etc. The storage unit 24 stores information used for measuring physical quantities.

[0030] As shown in FIG. 1 , the control unit 25 has a first signal processing unit 201 , a second signal processing unit 202 , a water vapor pressure measuring unit 203 , a concentration measuring unit 204 , a flow rate measuring unit 205 , an estimation unit 206 , and an output processing unit 207 .

[0031] The first signal processing unit 201 performs processing related to communication between the first ultrasonic transmitter / receiver 11 and the second ultrasonic transmitter / receiver 12 .

[0032] For example, when transmitting ultrasonic waves from the first ultrasonic transmitter / receiver 11 to the second ultrasonic transmitter / receiver 12, the first signal processing unit 201 outputs a signal instructing the first ultrasonic transmitter / receiver 11 to transmit ultrasonic waves to the first ultrasonic transmitter / receiver 11 via the first communication unit 21. When transmitting ultrasonic waves from the second ultrasonic transmitter / receiver 12 to the first ultrasonic transmitter / receiver 11, the first signal processing unit 201 outputs a signal instructing the second ultrasonic transmitter / receiver 12 to transmit ultrasonic waves to the second ultrasonic transmitter / receiver 12 via the first communication unit 21.

[0033] The first signal processing unit 201 also calculates a first propagation time (forward propagation time of the ultrasonic waves) t ｕｐ Specifically, the first signal processing unit 201 measures the first propagation time t based on the time when the ultrasonic wave is transmitted from the first ultrasonic transmitter / receiver 11 and the time when the ultrasonic wave transmitted from the first ultrasonic transmitter / receiver 11 is received by the second ultrasonic transmitter / receiver 12. ｕｐ Measure.

[0034] The first signal processing unit 201 also calculates a second propagation time t of the ultrasonic wave transmitted from the second ultrasonic transmitter / receiver 12 to the first ultrasonic transmitter / receiver 11 (the propagation time of the ultrasonic wave in the reverse direction) ｄｗ Specifically, the first signal processing unit 201 measures the second propagation time t based on the time when the ultrasonic wave is transmitted from the second ultrasonic transmitter / receiver 12 and the time when the ultrasonic wave transmitted from the second ultrasonic transmitter / receiver 12 is received by the first ultrasonic transmitter / receiver 11. ｄｗ Measure.

[0035] The first signal processing unit 201 calculates the first propagation time t ｕｐ and the second propagation time t ｄｗ The average time between these is calculated as the propagation time t.

[0036] The second signal processing unit 202 receives signals output from each sensor and performs predetermined processing on the received signals. When the second signal processing unit 202 receives a signal output from the pressure sensor 13, it performs predetermined signal processing on the received signal to determine the pressure P measured by the pressure sensor 13. When the second signal processing unit 202 receives a signal output from the temperature sensor 14, it performs predetermined signal processing on the received signal to determine the temperature T measured by the temperature sensor 14. When the second signal processing unit 202 receives a signal output from the humidity sensor 15, it performs predetermined signal processing on the received signal to determine the humidity H measured by the humidity sensor 15.

[0037] The water vapor pressure measuring unit 203 measures the water vapor pressure of the water vapor contained in the mixed gas flowing through the flow path 101. The water vapor pressure measuring unit 203 measures the water vapor pressure P of the water vapor using the temperature of the mixed gas measured by the temperature sensor 14 and the humidity of the mixed gas measured by the humidity sensor 15. ｗ Specifically, the water vapor pressure measuring unit 203 measures the water vapor pressure P ｗ Here, T in Equation 1 is the temperature of the mixed gas measured by the temperature sensor 14, and H is the humidity of the mixed gas measured by the humidity sensor 15.

[0038]

[0039] The concentration measurement unit 204 measures the water vapor concentration, which is the concentration of water vapor contained in the mixed gas, and the gas concentration, which is the concentration of a gas other than water vapor that is contained in the mixed gas. Here, the concentration measurement unit 204 measures the hydrogen concentration (hydrogen concentration) as the gas concentration. The concentration measurement unit 204 measures the water vapor concentration using the water vapor pressure measured by the water vapor pressure measurement unit 203 and the pressure of the mixed gas measured by the pressure sensor 13, and measures the gas concentration using the measured water vapor concentration.

[0040] The concentration measurement unit 204 measures the water vapor pressure P ｗ and a water vapor concentration x, which is the concentration of water vapor contained in the mixed gas based on the pressure P of the mixed gas measured by the pressure sensor 13. ｗSpecifically, the concentration measurement unit 204 measures the water vapor concentration x using the following equation 2: ｗ Ask for.

[0041]

[0042] Furthermore, the concentration measurement unit 204 measures the gas concentration, which is the concentration of a gas that is contained in the mixed gas and is different from water vapor, based on the calculated water vapor concentration, the propagation time of the ultrasonic waves in the pair of ultrasonic transmitter / receivers (the first ultrasonic transmitter / receiver 11 and the second ultrasonic transmitter / receiver 12), and the temperature T of the temperature sensor 14. For example, the concentration measurement unit 204 measures the gas concentration, which is the concentration of a gas that is contained in the mixed gas and is different from water vapor, based on the calculated water vapor concentration x ｗ The concentration of hydrogen contained in the mixed gas (hydrogen concentration) is measured based on the propagation time of the ultrasonic waves. Here, the sound speed c of the mixed gas, the molecular weight M of the mixed gas, and the specific heat ratio γ (= c ｐ / c ｖ ), the temperature T of the mixed gas, and the gas constant R, the relationship shown in Equation 3 holds true. ｐ is the constant pressure molar specific heat. ｖ is the molar specific heat at constant volume.

[0043]

[0044] In this embodiment, the mixed gas contains hydrogen, nitrogen, and water vapor. Here, the molecular weight of hydrogen is M １ , specific heat at constant pressure is c ｐ１ , specific heat at constant volume is c ｖ１ and the molecular weight of nitrogen is M ２ , specific heat at constant pressure is c ｐ２ , specific heat at constant volume is c ｖ２ The molecular weight of water vapor is M ｗ , specific heat at constant pressure is c ｐｗ , specific heat at constant volume is c ｖｗ Furthermore, let the hydrogen concentration be x １ In this case, the following equations 4 to 6 hold true.

[0045]

[0046]

[0047]

[0048] By using Equations 4 to 6, Equation 3 can be transformed into Equation 7.

[0049]

[0050] The concentration measurement unit 204 calculates the hydrogen concentration x １ Ask for.

[0051] The flow rate measurement unit 205 measures the flow rate of the mixed gas in the flow path 101 using the ultrasonic wave propagation time, the water vapor concentration, and the gas concentrations (hydrogen concentration, nitrogen concentration). The flow rate measurement unit 205 calculates the flow rate Q of the mixed gas using the following equations 8 and 9. Equation 8 calculates the tentative flow rate Q ０ This is a formula for calculating the provisional flow rate Q ０ is calculated by multiplying the cross-sectional area S of the flow path 101 by the flow velocity V. In addition, the flow velocity V, the length L of the ultrasonic propagation path 106 (the distance between the first ultrasonic transducer 11 and the second ultrasonic transducer 12), and the first propagation time t ｕｐ , the second propagation time t ｄｗ and the angle θ of the ultrasonic propagation path 106 with respect to the flow path 101, ０ =SV" can be transformed into the right side of equation 8. Here, R Ｋ is the flow coefficient.

[0052]

[0053]

[0054] In addition, the flow coefficient R Ｋ is the kinematic viscosity ν, the characteristic length D, and the flow velocity V ｍ where Re is the Reynolds number. That is, the Reynolds number Re is calculated by the formula "Re = V ｍ The characteristic length D is, for example, the length (height) of the flow channel 101 in the Z direction. The function f(Re) is a predetermined function. ｍ is the flow velocity corresponding to the flow rate measured by the standard device during calibration (hereinafter referred to as the reference flow rate) performed as a preliminary evaluation.

[0055]

[0056] Here, the kinetic viscosity ν is a value that depends on the temperature T in the flow path 101, the concentration of each gas (hydrogen, nitrogen, water vapor) contained in the mixed gas, and the pressure P. Furthermore, since the kinetic viscosity ν is "kinetic viscosity = viscosity / density," it can be obtained from the following equation 11. The transformation from the middle side to the right side of equation 11 is due to relational equation 2, "density = (molecular weight M × pressure P) / (gas constant R × temperature T), which is obtained from the gas state equation "pressure P × volume = number of moles × gas constant R × temperature T" and relational equation 1 "density = mass / volume." In other words, from the gas state equation and relational equation 1, the density ρ can be expressed in terms of the molecular weight M, pressure P, temperature T, and gas constant R. Here, the pressure P is the pressure measured by the pressure sensor 13. The temperature T is the temperature measured by the temperature sensor 14. Furthermore, the density ρ is determined by the gas concentration, temperature, and pressure. Therefore, in relational equation 2, the molecular weight M is a function (see equation 4) with the concentration as a variable.

[0057]

[0058] μ(x, T) in Equation 11 can be calculated from the viscosity of each gas (hydrogen, nitrogen, water vapor) contained in the mixed gas. The flow rate measurement unit 205 calculates the viscosity of each gas using a known method. The flow rate measurement unit 205 calculates the viscosity μ of the mixed gas using the viscosity of each gas calculated using a known method and the concentration of each gas (hydrogen concentration, nitrogen concentration, water vapor concentration) that has already been calculated.

[0059] Here, the flow coefficient R Ｋ We will explain how to calculate this.

[0060] Flow coefficient R Ｋ is the provisional flow rate Q ０ and the reference flow rate Q ｍ and is expressed by the following equation 12. Here, the reference flow rate Q ｍ is the flow rate measured by the standard device at the time of calibration.

[0061]

[0062] The Reynolds number Re is calculated based on the reference flow rate Q ｍ In equation 13, ν represents the kinematic viscosity of the mixed gas, D represents the characteristic length, and S represents the cross-sectional area of ​​the flow path 101. ｍis the reference flow rate Q measured by the standard instrument during calibration ｍ is the flow velocity corresponding to

[0063]

[0064] The processing device 20 calculates the reference flow rate Q using Equations 12 and 13. ｍ When the Reynolds number Re is changed, the provisional flow rate Q obtained from the measurement value ０ The flow coefficient R calculated using Ｋ Multiple combinations of (Re, R Ｋ ) is calculated as a preliminary evaluation, and the Reynolds number Re and the flow coefficient R Ｋ The relational expression is calculated and stored in advance.

[0065] Furthermore, using Equations 12 and 13, the Reynolds number Re and the flow coefficient R Ｋ The characteristic length D and the cross-sectional area S are known values ​​in the physical quantity measurement system 1, and the kinematic viscosity ν and the provisional flow rate Q ０ is a value that has already been calculated. That is, the flow coefficient R Ｋ is expressed as a linear function using the Reynolds number Re. In other words, Equation 14 is expressed as a linear function using the Reynolds number Re and the flow coefficient R Ｋ is a linear function that expresses the relationship between the provisional flow rate Q ０ and the value ((νS) / (Q ０ D) is a function with coefficients.

[0066]

[0067] The flow rate measurement unit 205 measures the Reynolds number Re and the flow rate coefficient R obtained by the preliminary evaluation. Ｋ Using the relational expression that expresses the relationship between Ｋ Specifically, the flow rate measurement unit 205 calculates the provisional flow rate Q by finding the intersection A0 between the graph G1 (see FIG. 4) represented by the relational expression obtained by the preliminary evaluation and the graph G2 (see FIG. 4) represented by the equation 14. ０ The flow coefficient R corresponding to Ｋ It is more preferable that the flow velocity measured by the flow rate measuring unit 205 is calculated at a value where the Reynolds number is in the laminar flow region, since this stabilizes the measured value.

[0068] The flow rate measurement unit 205 calculates the flow rate coefficient R Ｋ and calculate the flow rate Q using Equation 9. ０ is the propagation time of the ultrasonic waves obtained from the pair of ultrasonic transducers 11 and 12 (first propagation time t ｕｐ and the second propagation time t ｄｗ The flow rate Q is calculated using the flow coefficient R obtained from the Reynolds number Re. Ｋ and provisional flow rate Q ０ Therefore, it can be said that the flow rate measurement unit 205 measures the flow rate Q of the mixed gas in the flow path 101 using the Reynolds number Re and the propagation time of the ultrasonic waves obtained from the pair of ultrasonic transmitter-receivers 11 and 12.

[0069] Here, the kinematic viscosity ν appears in both Equation 10 and Equation 13. That is, the flow coefficient R Ｋ is a value based on the kinematic viscosity ν of the mixed gas. According to Equation 13, the Reynolds number Re is a coefficient of the kinematic viscosity ν. In other words, the flow coefficient R Ｋ is a value obtained by using a linear function of the Reynolds number, with a coefficient based on the kinematic viscosity ν of the mixed gas. Ｋ is a value obtained from a linear function of the Reynolds number, the coefficient of which is based on the kinematic viscosity ν of the mixed gas, and a relational expression that expresses the relationship between the Reynolds number obtained by a pre-evaluation and the flow coefficient.

[0070] The processing device 20 uses the Reynolds number Re and the flow coefficient R calculated by the pre-evaluation instead of using the relational expression obtained by the pre-evaluation. Ｋ and multiple combinations (Re, R Ｋ ) may be used.

[0071] The estimation unit 206 estimates the pressure loss inside the flow path 101. The estimation unit 206 estimates the pressure loss inside the flow path 101 based on the flow velocity u of the mixed gas, the pressure P of the mixed gas, the viscosity μ of the mixed gas, and the viscosity μ of the reference gas (here, hydrogen contained in the mixed gas). ０ and the Reynolds number Re, the pressure loss E ０ Here, viscosity μ ０is the viscosity when hydrogen is at 1 atm, for example. The flow velocity u of the mixed gas is obtained by dividing the flow rate Q of the mixed gas by the cross-sectional area S of the flow path 101. That is, the estimation unit 206 calculates the flow velocity u of the mixed gas obtained from the flow rate Q of the mixed gas, the pressure P of the mixed gas, the viscosity μ of the mixed gas, and the viscosity μ of the reference gas (hydrogen). ０ and the Reynolds number Re, the pressure loss E ０ Here, the reference gas is a gas that serves as a reference when calculating the pressure loss. In this embodiment, the reference gas is a gas (hydrogen) contained in the mixed gas, but the reference gas may be a gas that is not contained in the mixed gas.

[0072] The estimation unit 206 calculates a gauge pressure Pg based on atmospheric pressure using the pressure P of the mixed gas. The estimation unit 206 calculates a gauge pressure Pg based on atmospheric pressure using the Reynolds number Re, the flow velocity u of the mixed gas, the viscosity μ of the mixed gas, and the viscosity μ of the reference gas. ０ and gauge pressure Pg, the pressure loss E ０ Estimate.

[0073] The estimation unit 206 calculates the converted pressure loss value E under the reference environment using the following equation 15, which is stored in the storage unit 24 as information used to measure the physical quantity: １ The reference environment is an environment where hydrogen is at 20°C and 1 atm. Equation 15 is a function that expresses the relationship between the pressure loss, which is a measurement value measured under the reference environment, and a multiplication value obtained by multiplying the result (u / μ) of dividing the flow velocity u of the mixed gas by the viscosity μ of the mixed gas, which is obtained in advance by an experiment or the like, by the Reynolds number Re.

[0074]

[0075] The estimation unit 206 estimates the gauge pressure Pg, the viscosity μ of the mixed gas, the viscosity μ of the reference gas (hydrogen), ０ , and the converted pressure loss value E １ is used to estimate the pressure loss.

[0076] The estimation unit 206 calculates a correction value α according to a multiplication value obtained by multiplying the result (u / μ) of dividing the flow velocity u of the mixed gas by the viscosity μ of the mixed gas by the Reynolds number Re. For example, if the multiplication value is 2000 or less, the estimation unit 206 sets the correction value α to "0." If the multiplication value is greater than 2000 and less than or equal to 4000, the estimation unit 206 sets the correction value α to "1." If the multiplication value is greater than 4000, the estimation unit 206 sets the correction value α to "1.5."

[0077] The estimation unit 206 calculates the corrected gauge pressure g(Pg), which is a value obtained by multiplying the gauge pressure Pg by the correction value α, using the following equation 16.

[0078]

[0079] The estimation unit 206 estimates the corrected gauge pressure g (Pg), the viscosity μ of the mixed gas, and the viscosity μ of the reference gas (hydrogen). ０ , converted pressure loss value E １ , and using the following equation 17, the pressure loss E ０ Estimate.

[0080]

[0081] The output processing unit 207 receives the gas concentration (for example, hydrogen concentration) measured by the concentration measuring unit 204, the flow rate Q calculated by the flow rate measuring unit 205, and the pressure loss E estimated by the estimation unit 206. ０ is output to the fuel cell system 2 via the third communication unit 23.

[0082] (3) Operation (3.1) Overview of Operation Here, an overview of the operation of the physical quantity measuring system 1 will be described with reference to FIG.

[0083] The first signal processing unit 201 performs a first measurement process (step S1). Specifically, the first signal processing unit 201 measures a first propagation time t ｕｐ The first signal processing unit 201 also measures the second propagation time t ｄｗ Furthermore, the first signal processing unit 201 measures the first propagation time t ｕｐ and the second propagation time tｄｗ The propagation time t is calculated as the average time between the

[0084] The second signal processing unit 202 performs a second measurement process (step S2). Specifically, the second signal processing unit 202 determines the pressure P measured by the pressure sensor 13 based on the signal output from the pressure sensor 13. The second signal processing unit 202 determines the temperature T measured by the temperature sensor 14 based on the signal output from the temperature sensor 14. The second signal processing unit 202 determines the humidity H measured by the humidity sensor 15 based on the signal output from the humidity sensor 15.

[0085] The water vapor pressure measurement unit 203 performs a water vapor pressure measurement process (step S3). ｗ Specifically, the water vapor pressure measuring unit 203 acquires the temperature T of the mixed gas measured by the temperature sensor 14 and the humidity H of the mixed gas measured by the humidity sensor 15 from the second signal processing unit 202. The water vapor pressure measuring unit 203 calculates the water vapor pressure P using the acquired temperature T of the mixed gas and humidity H of the mixed gas and the above-mentioned Equation 1. ｗ Measure (calculate).

[0086] The concentration measurement unit 204 performs a water vapor concentration measurement process (step S4). The concentration measurement unit 204 measures the water vapor pressure P ｗ , the pressure P of the mixed gas measured by the pressure sensor 13, and the above-mentioned equation 2, the water vapor concentration x ｗ Measure.

[0087] The concentration measurement unit 204 performs a gas concentration measurement process (step S5). The concentration measurement unit 204 executes the gas concentration measurement process to calculate a gas concentration (hydrogen concentration) that is the concentration of a gas (here, hydrogen) that is contained in the mixed gas and that is different from water vapor.

[0088] The flow rate measurement unit 205 executes a flow rate measurement process to calculate the flow rate Q of the mixed gas (step S6).

[0089] The estimation unit 206 performs a pressure loss estimation process (step S7). The estimation unit 206 executes the pressure loss estimation process to estimate the pressure loss E０ Specifically, the estimation unit 206 estimates the flow velocity u of the mixed gas, the pressure P of the mixed gas, the viscosity μ of the mixed gas, and the viscosity μ of the reference gas. ０ and the Reynolds number Re, the pressure loss E ０ The reference gas is, for example, hydrogen contained in the gas mixture.

[0090] The output processing unit 207 performs output processing (step S8). The output processing unit 207 outputs the hydrogen concentration calculated in step S5, the flow rate Q calculated in step S6, and the pressure loss E estimated in step S7. ０ to the fuel cell system 2 via the third communication unit 23. The fuel cell system 2 outputs the received pressure loss E ０ Based on this, the flow rate of the mixed gas is determined so that the pressure loss is minimized.

[0091] (3.2) Gas Concentration Measurement Processing Here, the gas concentration measurement processing shown in step S5 of FIG. 5 will be described with reference to FIG.

[0092] The concentration measurement unit 204 performs a sound speed calculation process (step S101). The concentration measurement unit 204 calculates the sound speed c based on the propagation time t of the ultrasonic wave calculated by the first signal processing unit 201. Here, the propagation time t is the first propagation time t ｕｐ and the second propagation time t ｄｗ This is the average time.

[0093] The concentration measurement unit 204 performs a gas concentration calculation process (step S102). The concentration measurement unit 204 calculates the sound velocity c calculated based on the ultrasonic wave propagation time t, the water vapor concentration x calculated in the water vapor concentration measurement process (step S4 shown in FIG. 5), and the water vapor concentration t. ｗ , and the temperature T measured by the temperature sensor 14, the gas concentration (hydrogen concentration x １ ) is measured.

[0094] (3.3) Sound Speed ​​Calculation Processing Here, the sound speed calculation processing shown in step S101 of FIG. 6 will be described with reference to FIG.

[0095] The concentration measurement unit 204 receives the distance L (the distance between the first ultrasonic transmitter / receiver 11 and the second ultrasonic transmitter / receiver 12) stored in advance in the storage unit 24 and the first propagation time t ｕｐ and the second propagation time t ｄｗ and are acquired (step S151).

[0096] The concentration measurement unit 204 measures the first propagation time t ｕｐ and the second propagation time t ｄｗ The propagation time t, which is the average time between the time and the time (step S152).

[0097] The concentration measurement unit 204 calculates the sound speed c using the distance L acquired in step S151 and the propagation time t calculated in step S152 (step S153).

[0098] (3.4) Gas Concentration Calculation Processing Here, the gas concentration calculation processing shown in step S102 of FIG. 6 will be described with reference to FIG.

[0099] The concentration measurement unit 204 acquires the temperature T determined in the second measurement process (step S2 shown in FIG. 5) (step S161).

[0100] The concentration measurement unit 204 calculates the sound velocity c calculated in the sound velocity calculation process (step S101 shown in FIG. 6) and the water vapor concentration x calculated in the water vapor concentration measurement process (step S4 shown in FIG. 5). ｗ is acquired (step S162).

[0101] The concentration measurement unit 204 acquires each parameter stored in advance in the storage unit 24 (step S163). The concentration measurement unit 204 acquires the gas constant R, the molecular weight M of hydrogen, １ , the molecular weight of nitrogen M ２ , the molecular weight of water vapor M ｗ , the constant pressure molar specific heat (c ｐ１ , c ｐ２ , c ｐｗ ), and the constant volume molar specific heat (c ｖ１ , c ｖ２ , c ｖｗ ), are acquired as parameters.

[0102] The concentration measurement unit 204 measures the hydrogen concentration x １ The concentration measurement unit 204 calculates the temperature T acquired in step S161, the sound speed c acquired in step S162, and the water vapor concentration x ｗ Using the parameters acquired in step S163 and Equation 7, the hydrogen concentration x １ Calculate.

[0103] (3.5) Flow Rate Measurement Processing Here, the flow rate measurement processing shown in step S6 of FIG. 5 will be described with reference to FIG.

[0104] The flow rate measurement unit 205 calculates the first propagation time t ｕｐ and the second propagation time t ｄｗ and are acquired (step S201).

[0105] The flow rate measuring unit 205 acquires each parameter stored in advance in the storage unit 24 (step S202). The flow rate measuring unit 205 acquires the cross-sectional area S of the flow path 101, the length L of the ultrasonic propagation path 106 (the distance L between the first ultrasonic transmitter / receiver 11 and the second ultrasonic transmitter / receiver 12), and the angle θ at which the ultrasonic propagation path 106 is inclined with respect to the flow path 101 as the parameters.

[0106] The flow rate measurement unit 205 performs a tentative flow rate calculation process (step S203). Specifically, the flow rate measurement unit 205 calculates the first propagation time t ｕｐ and the second propagation time t ｄｗ Using the cross-sectional area S, length L, and angle θ obtained in step S202 and equation 8, the provisional flow rate Q of the mixed gas is calculated. ０ is calculated (step S203).

[0107] The flow rate measurement unit 205 performs a flow rate coefficient calculation process (step S204). By performing the flow rate coefficient calculation process, the flow rate measurement unit 205 calculates the flow rate coefficient R Ｋ Calculate.

[0108] The flow rate measurement unit 205 calculates the provisional flow rate Q ０ and flow coefficient R Ｋ and Equation 9 to calculate the flow rate Q of the mixed gas (step S205).

[0109] (3.6) Flow Coefficient Calculation Processing Here, the flow coefficient calculation processing shown in step S204 of FIG. 9 will be described with reference to FIG.

[0110] The flow rate measurement unit 205 acquires the temperature T measured by the temperature sensor 14 and the pressure P measured by the pressure sensor 13 as measurement values ​​(step S251).

[0111] The flow rate measurement unit 205 acquires the concentrations of water vapor, hydrogen, and nitrogen contained in the mixed gas (step S252). １ , nitrogen concentration, and water vapor concentration x ｗ Here, the nitrogen concentration is obtained by "1-xx ｗ " is expressed as

[0112] The flow rate measuring unit 205 acquires each parameter stored in advance in the storage unit 24 (step S253). The flow rate measuring unit 205 acquires the characteristic length D and the cross-sectional area S of the flow path 101 as parameters. Furthermore, the flow rate measuring unit 205 acquires the viscosity of each gas (hydrogen, nitrogen, water vapor) contained in the mixed gas.

[0113] The flow rate measurement unit 205 measures the viscosity of each of hydrogen, nitrogen, and water vapor, and the water vapor concentration x ｗ , hydrogen concentration x １ and the nitrogen concentration, the viscosity μ of the mixed gas containing hydrogen, nitrogen, and water vapor is calculated (step S254).

[0114] The flow rate measurement unit 205 measures the water vapor concentration x ｗ , hydrogen concentration x １ and the nitrogen concentration and Equation 11 are used to calculate the kinematic viscosity ν of the mixed gas containing hydrogen, nitrogen, and water vapor (step S255).

[0115] The flow rate measurement unit 205 calculates the provisional flow rate Q by finding the intersection between the graph represented by the relational expression obtained by the preliminary evaluation and the graph represented by Equation 14. ０ The flow coefficient R corresponding to Ｋ is calculated (step S256).

[0116] (3.7) Pressure Loss Estimation Process Here, the pressure loss estimation process shown in step S7 of FIG. 5 will be described with reference to FIG.

[0117] The estimation unit 206 acquires the viscosity μ of the mixed gas calculated by the flow rate measurement unit 205, the flow rate Q, and the pressure P measured by the pressure sensor 13 as measurement values ​​(step S301).

[0118] The estimation unit 206 calculates the flow velocity u of the mixed gas (step S302) by dividing the flow rate Q of the mixed gas acquired in step S301 by the cross-sectional area S of the flow path 101.

[0119] The estimation unit 206 calculates a gauge pressure Pg based on atmospheric pressure using the pressure P of the mixed gas acquired in step S301 (step S303). The estimation unit 206 calculates the gauge pressure Pg by subtracting 101.325 [kPa] from the pressure P of the mixed gas. The estimation unit 206 calculates a converted pressure loss value E under the reference environment using the Reynolds number Re, the viscosity μ of the mixed gas, the flow velocity u of the mixed gas, and the above-mentioned equation (15). １ is calculated (step S304).

[0120] The estimation unit 206 performs a correction process (step S305). The estimation unit 206 calculates a correction value α according to a multiplication value (Re×(u / μ)) obtained by multiplying the result (u / μ) of dividing the flow velocity u of the mixed gas by the viscosity μ of the mixed gas by the Reynolds number Re. The estimation unit 206 calculates a corrected gauge pressure g (Pg), which is a value obtained by multiplying the gauge pressure Pg by the correction value α, using the above-mentioned Equation 16.

[0121] The estimation unit 206 estimates the pressure loss E ０ Specifically, the estimation unit 206 estimates the corrected gauge pressure g (Pg), the viscosity μ of the mixed gas, and the viscosity μ of the reference gas. ０ , converted pressure loss value E １ , and using the above-mentioned equation 17, the pressure loss E ０ Estimate.

[0122] (4) Advantages The physical quantity measuring system 1 of this embodiment includes a flow path 101 through which a mixed gas containing water vapor flows, and an estimation unit 206. The estimation unit 206 estimates a pressure loss inside the flow path 101. The estimation unit 206 estimates the pressure loss using the Reynolds number, the flow velocity of the mixed gas, the viscosity of the mixed gas, the viscosity of a reference gas, and the pressure of the mixed gas.

[0123] According to this configuration, the pressure loss is estimated using a value that is converted depending on the environment of the flow path through which the mixed gas flows, such as the pressure of the mixed gas, so that errors can be reduced.

[0124] (5) Modifications Modifications are listed below. The modifications described below can be applied in appropriate combination with the above-described embodiment.

[0125] (5.1) Modification 1 In the present disclosure, at least one of the pressure sensor 13, the temperature sensor 14, and the humidity sensor 15 is not an essential component of the physical quantity measuring system 1.

[0126] When the physical quantity measurement system 1 does not include the pressure sensor 13, the pressure of the mixed gas flowing through the flow path 101 may be acquired from an external device 30 shown in Fig. 12. That is, when the pressure of the mixed gas flowing through the flow path 101 is known by another means, the physical quantity measurement system 1 does not necessarily need to include the pressure sensor 13. The physical quantity measurement system 1 may acquire the pressure of the mixed gas flowing through the flow path 101, which is known by another means, from the external device 30 and use it as a measurement value.

[0127] When the physical quantity measurement system 1 does not include the temperature sensor 14, it may acquire the temperature of the mixed gas flowing through the flow path 101 from the external device 30. That is, when the temperature of the mixed gas flowing through the flow path 101 is known by another means, the physical quantity measurement system 1 does not necessarily need to include the temperature sensor 14. The physical quantity measurement system 1 may acquire the temperature of the mixed gas flowing through the flow path 101, which is known by another means, from the external device 30 and use it as a measurement value.

[0128] When the physical quantity measurement system 1 does not include the humidity sensor 15, it may acquire the humidity of the mixed gas flowing through the flow path 101 from the external device 30. In other words, when the humidity of the mixed gas flowing through the flow path 101 is known by another means, the physical quantity measurement system 1 does not necessarily need to include the humidity sensor 15. The physical quantity measurement system 1 may acquire the humidity of the mixed gas flowing through the flow path 101, which is known by another means, from the external device 30 and use it as a measurement value.

[0129] The concentration measurement unit 204 of the physical quantity measurement system 1 of Modification 1 calculates the water vapor pressure using the humidity and temperature of the mixed gas. The concentration measurement unit 204 of the physical quantity measurement system 1 of Modification 1 calculates the water vapor concentration using the calculated water vapor pressure and the pressure of the mixed gas.

[0130] In this case, if the physical quantity measurement system 1 of variant 1 does not have any of the pressure sensor 13, temperature sensor 14, and humidity sensor 15, the concentration measurement unit 204 of variant 1 acquires all of the pressure, humidity, and temperature of the mixed gas from the external device 30.

[0131] Alternatively, the physical quantity measurement system 1 of Modification 1 may measure one or two of the pressure, temperature, and humidity of the mixed gas. In this case, the physical quantity measurement system 1 of Modification 1 further includes one or two sensors that perform measurements according to one or two of the measurement targets of the mixed gas pressure, temperature, and humidity of the mixed gas. That is, the physical quantity measurement system 1 of Modification 1 further includes one or two sensors from a pressure sensor 13 that measures the pressure of the mixed gas, a temperature sensor 14 that measures the temperature of the mixed gas, and a humidity sensor 15 that measures the humidity of the mixed gas, according to one or two of the measurement targets of the mixed gas pressure, temperature, and humidity of the mixed gas. The concentration measurement unit 204 of Modification 1 externally acquires the pressure, temperature, and humidity of the mixed gas that are not the measurement targets of the mixed gas pressure, temperature, and humidity of the mixed gas. With this configuration, some of the pressure, temperature, and humidity of the mixed gas can be acquired from the sensors, and the rest can be acquired externally.

[0132] (5.2) Modification 2 The flow channel body 10 may further include one or more partition plates. The one or more partition plates divide the flow channel 101 into multiple sections in the height direction (Z direction) of the flow channel 101. By dividing the flow channel 101 into multiple sections with the one or more partition plates, a multi-layer flow channel is formed in the flow channel 101. This configuration increases the aspect ratio of the flow channel cross section of each layer of the multi-layer flow channel, making the flow two-dimensional, and rectifying the flow and stabilizing turbulence.

[0133] In this case, the representative length D is, for example, the length between the partition plates, or the length between one of the two side walls that face each other in the height H direction and form the flow path 101 and the partition plate closest to that side wall.

[0134] (5.3) Modification 3 The flow rate measurement unit 205 may convert the obtained flow rate Q into a flow rate at 0° C. and 1 atm (standard flow rate).

[0135] The flow rate measurement unit 205 may also use the determined flow rate Q or the standard flow rate to determine the flow rate of a gas (e.g., hydrogen) contained in the mixed gas. For example, the flow rate measurement unit 205 may multiply the determined flow rate Q or the standard flow rate by the concentration x of hydrogen. １ Multiply by this to calculate (measure) the hydrogen flow rate.

[0136] (5.4) Modification 4 The physical quantity measuring system 1 may include a plurality of temperature sensors 14. When the flow path main body 10 has a plurality of temperature sensors 14, the second signal processing unit 202 calculates the average value of the temperatures measured by the plurality of temperature sensors 14 as the temperature T of the mixed gas.

[0137] (5.5) Variation 5 The first ultrasonic transmitter / receiver 11 is arranged upstream and the second ultrasonic transmitter / receiver 12 is arranged downstream, facing each other, i.e., the arrangement direction of the first ultrasonic transmitter / receiver 11 and the second ultrasonic transmitter / receiver 12 intersects with the X direction, but this configuration is not limited to this.

[0138] The first ultrasonic transmitter / receiver 11 and the second ultrasonic transmitter / receiver 12 may be arranged along the X direction, but not intersect with the X direction.

[0139] In this case, the ultrasonic waves output from the first ultrasonic transmitter / receiver 11 are reflected within the flow path 101, and the reflected ultrasonic waves are input to the second ultrasonic transmitter / receiver 12. Furthermore, the ultrasonic waves output from the second ultrasonic transmitter / receiver 12 are reflected within the flow path 101, and the reflected ultrasonic waves are input to the first ultrasonic transmitter / receiver 11. That is, the path of the ultrasonic waves is V-shaped and crosses the flow of the mixed gas in the flow path 101. That is, in the fifth modification as well, the pair of ultrasonic transmitters / receivers 11, 12 are arranged so that the ultrasonic waves cross the flow of the mixed gas in the flow path 101.

[0140] (5.6) Modification 6 In the embodiment, the mixed gas contains nitrogen as a gas other than hydrogen, but the present invention is not limited to this configuration. The mixed gas may contain gases other than nitrogen as a gas other than hydrogen, such as hydrocarbons (HCs) such as methane, carbon dioxide, helium, argon, and oxygen.

[0141] (5.7) Modification 7 In the embodiment, the mixed gas contains water vapor, but the present invention is not limited to this. The mixed gas does not have to contain water vapor.

[0142] (Other Modifications) The above embodiment is merely one of various embodiments of the present disclosure. The above embodiment can be modified in various ways depending on the design and the like as long as the object of the present disclosure can be achieved.

[0143] Furthermore, functions similar to those of the physical quantity measurement system 1 may be embodied as a physical quantity measurement method, a computer program, a non-transitory recording medium on which a program is recorded, or the like. A physical quantity measurement method according to one aspect is used in a physical quantity measurement system 1 including a flow path 101 through which a mixed gas flows. The physical quantity measurement method includes an estimation step of estimating a pressure loss inside the flow path 101. In the estimation step, the pressure loss is estimated using the Reynolds number, the flow velocity of the mixed gas, the viscosity of the mixed gas, the viscosity of a reference gas, and the pressure of the mixed gas. A program according to one aspect is a program for causing a computer system to function as the above-described physical quantity measurement method.

[0144] The physical quantity measurement system 1 according to the present disclosure includes a computer system. The computer system is primarily composed of a processor and a memory as hardware. The processor executes a program stored in the memory of the computer system to realize the functions of the physical quantity measurement system 1 according to the present disclosure. The program may be pre-recorded in the memory of the computer system, provided via a telecommunications line, or provided in a non-transitory recording medium such as a memory card, optical disk, or hard disk drive that is readable by the computer system. The processor of the computer system is composed of one or more electronic circuits including a semiconductor integrated circuit (IC) or a large-scale integrated circuit (LSI). The integrated circuits, such as ICs and LSIs, are referred to by different names depending on the degree of integration, and include integrated circuits called system LSIs, very large-scale integrations (VLSIs), or ultra-large-scale integrations (ULSIs). Furthermore, field-programmable gate arrays (FPGAs), which are programmed after the LSI is manufactured, or logic devices that allow the reconfiguration of internal connections or internal circuit partitions of the LSI, can also be used as processors. The electronic circuits may be integrated into one chip or distributed across multiple chips. The chips may be integrated into one device or distributed across multiple devices. The computer system referred to here includes a microcontroller having one or more processors and one or more memories. Therefore, the microcontroller is also composed of one or more electronic circuits including a semiconductor integrated circuit or a large-scale integrated circuit.

[0145] Furthermore, it is not essential for the physical quantity measurement system 1 that multiple functions are integrated into one housing, and the components of the physical quantity measurement system 1 may be distributed across multiple housings. Furthermore, at least some of the functions of the physical quantity measurement system 1 may be realized by the cloud (cloud computing) or the like.

[0146] (Summary) As described above, the physical quantity measurement system (1) of the first aspect includes a flow path (101) through which a mixed gas flows, and an estimation unit (206). The estimation unit (206) estimates a pressure loss inside the flow path (101). The estimation unit (206) estimates the pressure loss using the Reynolds number, the flow velocity of the mixed gas, the viscosity of the mixed gas, the viscosity of a reference gas, and the pressure of the mixed gas.

[0147] According to this aspect, the pressure loss is estimated using a value that is converted depending on the environment of the flow path through which the mixed gas flows, such as the pressure of the mixed gas, so that errors can be reduced.

[0148] In the physical quantity measurement system (1) of the second aspect, in the first aspect, the estimation unit (206) calculates a gauge pressure based on atmospheric pressure using the pressure of the mixed gas. The estimation unit (206) estimates the pressure loss using the Reynolds number, the flow velocity of the mixed gas, the viscosity of the mixed gas, the viscosity of the reference gas, and the gauge pressure.

[0149] According to this embodiment, when estimating the pressure loss of the mixed gas inside the flow path (101), the error can be reduced.

[0150] In the physical quantity measurement system (1) of the third aspect, in the second aspect, the estimation unit (206) calculates a converted pressure loss value under a reference environment using the Reynolds number, the flow velocity of the mixed gas, and the viscosity of the mixed gas. The estimation unit (206) estimates the pressure loss using the gauge pressure, the viscosity of the mixed gas, the viscosity of the reference gas, and the converted pressure loss value.

[0151] According to this embodiment, when estimating the pressure loss of the mixed gas inside the flow path (101), the error can be reduced.

[0152] In the physical quantity measurement system (1) of the fourth aspect, in the third aspect, the estimation unit (206) obtains a correction value corresponding to a multiplication value obtained by multiplying a result obtained by dividing the flow velocity of the mixed gas by the viscosity of the mixed gas by the Reynolds number. The estimation unit (206) calculates a corrected gauge pressure, which is a value obtained by multiplying the gauge pressure by the correction value. The estimation unit (206) estimates the pressure loss using the corrected gauge pressure, the viscosity of the mixed gas, the viscosity of the reference gas, and the converted pressure loss value.

[0153] According to this embodiment, when estimating the pressure loss of the mixed gas inside the flow path (101), the error can be reduced.

[0154] A physical quantity measurement system (1) of a fifth aspect is any one of the first to fourth aspects, further comprising a pressure sensor (13), a temperature sensor (14), a humidity sensor (15), a water vapor pressure measurement unit (203), and a concentration measurement unit (204). The mixed gas contains water vapor. The pressure sensor (13) measures the pressure of the mixed gas. The temperature sensor (14) measures the temperature of the mixed gas. The humidity sensor (15) measures the humidity of the mixed gas. The water vapor pressure measurement unit (203) measures the water vapor pressure of the water vapor using the temperature measured by the temperature sensor (14) and the humidity measured by the humidity sensor (15). The concentration measurement unit (204) measures a water vapor concentration, which is the concentration of water vapor contained in the mixed gas, and a gas concentration, which is the concentration of a gas contained in the mixed gas but different from water vapor. The concentration measurement unit (204) measures the water vapor concentration using the water vapor pressure measured by the water vapor pressure measurement unit (203) and the pressure of the mixed gas measured by the pressure sensor (13). The concentration measurement unit (204) measures the gas concentration using the measured water vapor concentration.

[0155] According to this aspect, the pressure loss is estimated using a value that is converted depending on the environment of the flow path through which the mixed gas flows, such as the pressure of the mixed gas, so that errors can be reduced.

[0156] A sixth aspect of the physical quantity measuring system (1) is the same as any one of the first to fifth aspects, further comprising a pair of ultrasonic transmitter-receivers (11, 12) and a flow rate measuring unit (205). The pair of ultrasonic transmitter-receivers (11, 12) transmit and receive ultrasonic waves and are arranged so that the ultrasonic waves cross the flow of the mixed gas in the flow path (101). The flow rate measuring unit (205) measures the flow rate of the mixed gas in the flow path (101) using the Reynolds number and the propagation time of the ultrasonic waves obtained from the pair of ultrasonic transmitter-receivers (11, 12). The estimation unit (206) estimates a pressure loss using the flow velocity of the mixed gas obtained from the flow rate of the mixed gas, the pressure of the mixed gas, the viscosity of the mixed gas, the viscosity of a reference gas, and the Reynolds number.

[0157] According to this aspect, the pressure loss is estimated using a value that is converted depending on the environment of the flow path through which the mixed gas flows, such as the pressure of the mixed gas, so that errors can be reduced.

[0158] A seventh aspect of the physical quantity measurement method is used in a physical quantity measurement system (1) including a flow path (101) through which a mixed gas flows. The physical quantity measurement method includes an estimation step of estimating a pressure loss inside the flow path (101). In the estimation step, the pressure loss is estimated using the Reynolds number, the flow velocity of the mixed gas, the viscosity of the mixed gas, the viscosity of a reference gas, and the pressure of the mixed gas.

[0159] According to this aspect, the pressure loss is estimated using a value that is converted depending on the environment of the flow path through which the mixed gas flows, such as the pressure of the mixed gas, so that errors can be reduced.

[0160] The program of the eighth aspect is a program for causing a computer system to execute the physical quantity measuring method of the seventh aspect.

[0161] According to this aspect, the pressure loss is estimated using a value that is converted depending on the environment of the flow path through which the mixed gas flows, such as the pressure of the mixed gas, so that errors can be reduced.

[0162] An integrated system (1000) of a ninth aspect includes the physical quantity measurement system (1) of any one of the first to sixth aspects and a fuel cell system (2). The physical quantity measurement system (1) estimates a pressure loss of a mixed gas flowing in from the fuel cell system (2).

[0163] According to this aspect, the pressure loss is estimated using a value that is converted depending on the environment of the flow path through which the mixed gas flows, such as the pressure of the mixed gas, so that errors can be reduced.

[0164] REFERENCE SIGNS LIST 1 Physical quantity measurement system 11 Ultrasonic transducer (first ultrasonic transducer) 12 Ultrasonic transducer (second ultrasonic transducer) 13 Pressure sensor 14 Temperature sensor 15 Humidity sensor 20 Processing device 101 Flow path 203 Water vapor pressure measurement unit 204 Concentration measurement unit 205 Flow rate measurement unit 206 Estimation unit

Claims

1. A physical quantity measurement system comprising: a flow path through which a mixed gas flows; and an estimation unit that estimates a pressure loss inside the flow path, wherein the estimation unit estimates the pressure loss using a Reynolds number, a flow velocity of the mixed gas, a viscosity of the mixed gas, a viscosity of a reference gas, and a pressure of the mixed gas.

2. The physical quantity measurement system according to claim 1, wherein the estimation unit calculates a gauge pressure based on atmospheric pressure using the pressure of the mixed gas, and estimates the pressure loss using the Reynolds number, the flow velocity of the mixed gas, the viscosity of the mixed gas, the viscosity of the reference gas, and the gauge pressure.

3. The physical quantity measurement system according to claim 2, wherein the estimation unit calculates a converted pressure loss value under a reference environment using the Reynolds number, the flow velocity of the mixed gas, and the viscosity of the mixed gas, and estimates the pressure loss using the gauge pressure, the viscosity of the mixed gas, the viscosity of the reference gas, and the converted pressure loss value.

4. The physical quantity measurement system of claim 3, wherein the estimation unit: obtains a correction value corresponding to a multiplied value obtained by multiplying the flow velocity of the mixed gas by the viscosity of the mixed gas by the Reynolds number; calculates a corrected gauge pressure by multiplying the gauge pressure by the correction value; and estimates the pressure loss using the corrected gauge pressure, the viscosity of the mixed gas, the viscosity of the reference gas, and the converted pressure loss value.

5. The physical quantity measurement system according to any one of claims 1 to 4, wherein the mixed gas contains water vapor, and the physical quantity measurement system further comprises: a pressure sensor that measures the pressure of the mixed gas; a temperature sensor that measures the temperature of the mixed gas; a humidity sensor that measures the humidity of the mixed gas; a water vapor pressure measurement unit that measures the water vapor pressure of the water vapor using the temperature measured by the temperature sensor and the humidity measured by the humidity sensor; and a concentration measurement unit that measures a water vapor concentration that is the concentration of the water vapor contained in the mixed gas and a gas concentration that is the concentration of a gas that is contained in the mixed gas but is different from the water vapor, and wherein the concentration measurement unit measures the water vapor concentration using the water vapor pressure measured by the water vapor pressure measurement unit and the pressure of the mixed gas measured by the pressure sensor, and measures the gas concentration using the measured water vapor concentration.

6. A physical quantity measurement system according to any one of claims 1 to 5, further comprising: a pair of ultrasonic transmitters and receivers that transmit and receive ultrasonic waves and are arranged so that the ultrasonic waves intersect the flow of the mixed gas in the flow path; and a flow rate measurement unit that measures the flow rate of the mixed gas in the flow path using the Reynolds number and the propagation time of the ultrasonic waves obtained from the pair of ultrasonic transmitters and receivers, wherein the estimation unit estimates the pressure loss using the flow velocity of the mixed gas obtained from the flow rate of the mixed gas, the pressure of the mixed gas, the viscosity of the mixed gas, the viscosity of the reference gas, and the Reynolds number.

7. A physical quantity measurement method used in a physical quantity measurement system having a flow path through which a mixed gas flows, the physical quantity measurement method including an estimation step of estimating a pressure loss inside the flow path, in which the pressure loss is estimated using a Reynolds number, a flow velocity of the mixed gas, a viscosity of the mixed gas, a viscosity of a reference gas, and a pressure of the mixed gas.

8. A program for causing a computer system to execute the physical quantity measuring method according to claim 7.

9. An integrated system comprising: a physical quantity measurement system according to any one of claims 1 to 6; and a fuel cell system, wherein the physical quantity measurement system estimates the pressure loss of the mixed gas flowing in from the fuel cell system.

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