Differential pressure liquid flow controller

Abstract

The fluid system includes a capillary tube, first and second temperature sensors, first and second pressure sensors, and a processor coupled to the sensors. The processor is configured to execute instructions to determine an output using sensor data and using fluid parameter data received via an interface coupled to the processor. The processor is coupled to a control in fluid communication with the capillary tube.

Description

[0001] Priority Declaration

[0002] This patent application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 233,029 (File No. 4270.024PRV), filed on August 13, 2021, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This document relates generally, but not in a limited way, to liquid flow controllers with improved performance. Background Technology

[0004] Accurate measurement and control of liquid or gas flow rates are crucial in many industrial, commercial, and medical applications. For example, semiconductor manufacturing requires fluid handling equipment where accuracy is critical for assembly and performance. Flow controllers provide a fluid path through which the liquid flow rate can be measured or controlled.

[0005] Measurement accuracy and control precision can be affected by many factors, including contaminants in the liquid and irregularities in the fluid path. Summary of the Invention

[0006] This topic includes flow controllers configured for accurate flow measurement and control. One example compensates for variations in fluid viscosity and density. Relationships can be established between variables such as temperature, pressure, fluid-specific parameters, and fluid flow rate. Measurement sensors can be configured to sense a first set of physical parameters and achieve accurate measurement of a second set of physical parameters.

[0007] The inventors have recognized that, among other things, the problem to be solved may include: receiving data corresponding to a fluid system, and using a flow controller to measure or control the fluid flow rate. According to one example, the device can be configured to receive data associated with the temperature of the fluid in a capillary, the pressure difference across the capillary, flow rate information from a flow sensor, and fluid parameter data, and based on this data, the device can determine flow control settings. The flow control settings, when implemented, change the fluid flow rate and provide a negative feedback signal, through which the device can repeat data collection and readjust the control to change the fluid flow rate again.

[0008] According to one example, the device can be configured to receive data associated with the temperature of the fluid in the capillary, the pressure difference across the capillary, and fluid parameter data, and based on this data, the device can determine the fluid flow rate through the capillary. The fluid flow rate can be indicated as mass flow rate or volumetric flow rate.

[0009] According to one example, the device can be configured to receive data associated with the temperature of the fluid in the capillary, the pressure difference across the capillary, and a measured fluid flow rate. The measured fluid flow rate can be a volumetric flow rate or a mass flow rate. Based on the received data, the device can calculate fluid parameters. The fluid parameters can be related to the fluid's composition or selected physical parameters. The fluid parameters can be associated with fluid density, fluid viscosity, or other physical parameters.

[0010] According to one example, the device can be configured to receive data associated with the temperature of the fluid in the capillary, the fluid pressure within the capillary, and a measured fluid flow rate. The measured fluid flow rate can be either a volumetric flow rate or a mass flow rate. Additionally, the device can receive data associated with physical parameters of the fluid in the capillary. Based on the received data, the device can calculate the pressure difference of the fluid in the capillary. The pressure difference can be associated with measurements of the fluid pressure within the capillary at a first axial position and measurements of the fluid pressure within the capillary at a second axial position.

[0011] Each of these non-restrictive examples can exist independently, or can be combined with one or more examples in various permutations or combinations.

[0012] This overview is intended to provide an overview of the subject matter of this patent application. It is not intended to provide an exclusive or exhaustive description of the invention. Detailed descriptions are included to provide additional information regarding this patent application. Attached Figure Description

[0013] In drawings that are not necessarily drawn to scale, similar reference numerals may describe similar parts in different views. Similar reference numerals with different letter suffixes may indicate different instances of similar parts. The drawings are generally illustrated by way of example rather than limitation, showing the various embodiments discussed in this document.

[0014] Figure 1 A schematic diagram illustrating an example based on this topic is shown.

[0015] Figure 2 A flowchart of an example method according to this topic is shown. Detailed Implementation

[0016] Figure 1 A schematic diagram of a system 100 according to an example of this topic is shown. System 100 can be configured into a uniform package and is sometimes referred to as a device.

[0017] System 100 includes a capillary 116 having a cavity through which fluid can flow. In the illustrated example, capillary 116 is equipped with pressure sensors 110A and 110B, sometimes referred to as a first pressure sensor and a second pressure sensor. In various examples, the direction of fluid flow through capillary 116 can be from left to right or from right to left.

[0018] In the example shown, capillary 116 is equipped with temperature sensors 120A and 120B, sometimes referred to as a first temperature sensor and a second temperature sensor. In the figure, the temperature sensors are coupled to fittings fixed to the ends (first end and second end) of capillary 116. In other examples, a single (rather than dual) temperature sensor is provided and positioned at either end or between the ends. The temperature sensor may have a sensing surface configured to measure the temperature of the capillary wall or the temperature of the fluid within the capillary.

[0019] Output signals from pressure sensors 110A and 110B and temperature sensors 120A and 120B are coupled to processor 114. Processor 114 may include an analog or digital computer having instructions or configurations tailored to implement the methods described herein. Processor 114 is coupled to interface 112. Interface 112 may include a user interface and has a keyboard, cursor control device (e.g., mouse, trackball, or touchpad), display, printer, microphone or speaker, or other components to allow human interaction with processor 114 or system 100. In one example, interface 112 includes a network interface configured to couple to a remote device via a wired or wireless connection.

[0020] In the illustrated example, processor 114 is coupled to flow sensor 122. Flow sensor 122 may be located upstream or downstream of capillary 116. In various examples, flow sensor 122 includes a mass flow sensor or a volumetric flow sensor. The sensor can provide an output signal accessible to processor 114, wherein the signal is a function of the fluid flow rate through system 100.

[0021] In the illustrated example, processor 114 is coupled to control 124. Control 124 can be located upstream or downstream of capillary 116, and can be located at the proximal or distal end of capillary 116. In various examples, control 124 includes a valve or pump or other hydraulic component with adjustable settings. In the case of a motor-driven pump, control 124 may include a signal line through which processor 114 can set the motor speed, and thus set the flow rate through capillary 116. In the figure, control 124 is depicted as being connected in series with capillary 116, but other configurations are also contemplated. For example, control 124 may include a bypass or diversion fluid path through which the flow rate through capillary 116 can be adjusted. The signal line between processor 114 and control 124 may include a setting line that can be controlled by control 124, and a readout line that can receive signals corresponding to the settings of control 124 by processor 114.

[0022] Figure 2 A flowchart of method 200 according to an example of this subject matter is shown. At 210, method 200 includes receiving data. The data may include information relating to temperature from a temperature sensor or pressure from a pressure sensor. Additionally, the received data may include fluid flow rate information from a flow sensor or device configuration information from a control device coupled to the capillary of the system. In some examples, receiving data may include receiving manually input information regarding physical parameters of the fluid used in the system. The data may be received from a user interface or from an interface coupled to a data network or communication network.

[0023] At 220, method 200 includes performing calculations. Calculations may include executing an algorithm according to stored instructions or programming. Calculations may include determining temperature, determining pressure, or differential pressure. In other examples, calculations may include determining flow rate or generating an output signal corresponding to the flow rate, differential pressure, temperature, or physical parameters of the fluid.

[0024] At 230, method 200 includes providing an output. Providing an output may include generating a human-perceptible signal, such as displaying a value or parameter. In various examples, generating the output includes generating a signal configured to operate a control device in a fluid path. For example, the signal may control the fluid flow rate, or the fluid pressure, or another parameter.

[0025] In Poiseuille flow, a liquid moves under the influence of a pressure gradient. This gradient can be represented by a pressure difference. The pressure difference is the pressure difference found between the inlet and outlet of a tube or capillary. The pressure difference is a function of the fluid viscosity, volumetric flow rate, and parameters constraining the tube. Fluid viscosity is, in turn, a function of temperature, whereby increasing temperature decreases viscosity.

[0026] Poiseuille's equations are satisfied as long as the fluid flow rate is laminar rather than turbulent. Laminar flow is associated with fluid flow rates below the critical Reynolds number (Re).

[0027] As the flow rate increases, the Reynolds number will increase to reach a critical value, beyond which laminar flow will change to transitional flow, and then to turbulent flow. Since the Reynolds number is inversely proportional to viscosity, and viscosity decreases with increasing temperature, it is expected that this change will occur at lower flow rates when the liquid temperature is higher. Experimental tests can determine the threshold flow rate and the associated critical Reynolds number at different temperatures.

[0028] Fluid flow rate can be graphically represented by a Q-ΔP curve, which plots the fluid flow rate and pressure difference.

[0029] Theoretical flow rate and measured flow rate can differ, and therefore the instrument can be calibrated to provide accurate measurements. In some cases, flow rate errors can be related to viscosity and the difference between theoretical and measured results. Since viscosity is a function of temperature, accurate temperature measurements provide accurate flow rate measurements.

[0030] Temperature can be measured directly or indirectly. In direct temperature measurement, the sensing surface of the temperature sensor is in contact with the liquid being measured. In indirect temperature measurement, the sensing surface of the temperature sensor is fixed to measure the wall temperature of the liquid flow channel.

[0031] Indirect measurements can avoid the complexities of direct contact with the liquid being tested. For example, concerns about contaminants may make direct measurements undesirable or impossible.

[0032] One example in this topic involves directly measuring the temperature of a liquid, which is currently under development. One example is configured to measure the temperature of a liquid pipeline and to improve the method for better flow rate calculations.

[0033] One example in this topic aims to achieve a better understanding of the relationship between flow measurement results and temperature. For instance, accurate temperature measurements can extend the operating range of liquid flow controllers.

[0034] Liquid temperature can be measured directly at the inlet, outlet, or both of the liquid flow controller (LFC). Alternatively, the LFC body temperature can be measured before and after the capillary tube.

[0035] One example considers the effect of temperature on the viscosity of Q deltP DP LFC. Q-deltP refers to the mass flow rate differential pressure.

[0036] One example includes a configuration for directly measuring the liquid temperature before and after the flow resistance, and also for measuring the body temperature.

[0037] One example includes a configuration for the liquid temperature directly used to assess the impact of actual temperature versus body temperature on the test.

[0038] In various examples of this subject, temperature is associated with measurements taken at a single temperature sensor site or at multiple temperature sensor sites. The temperature sensors may be fixed to the capillary wall and provide a signal associated with the fluid temperature. The sensor sites may be located at an axial position along the length of the capillary, and in various examples, the sensor sites are located at or between the ends. In some examples, the temperature sensor has a sensing surface that is in physical contact with the fluid in the capillary.

[0039] The following formula can help characterize the fluid in a capillary.

[0040]

[0041] μ 实际 =f(T)=Ae B / T .

[0042] This expresses the relationship between temperature (B) and viscosity μ as a function of constants A and B.

[0043] Theoretical flow rate conversion is performed based on calibration.

[0044] Q m =ρQ v .

[0045] This represents the relationship between mass flow rate (mass per unit time) and volumetric flow rate (volume per unit time), where ρ represents density (mass per unit volume).

[0046]

[0047] This formula shows that the mass flow rate is a function of the product of the pressure difference (pressure difference across the capillary) and the ratio of the actual density to the standard density, and the product of the ratio of the standard viscosity to the actual viscosity.

[0048] It should be noted that there are relationships between some of the various parameters. For example, viscosity is a fluid parameter that is affected by temperature. Additionally, pressure difference is related to temperature.

[0049] Transitional flow and turbulence can be observed at different temperatures. In some instances, the critical Re is 2500.

[0050] Features at the capillary inlet, such as irregularities in the wall profile or edges, can affect the critical Reynolds number. Irregularities can interfere with the inlet flow and thus lower the critical Reynolds number. Irregularities at the capillary inlet can be addressed by removing sharp edges and providing an appropriate profile radius. In one example, a filter could be positioned upstream of the capillary inlet to trap particles and debris. However, the filter could be positioned far enough away that it itself does not cause interference.

[0051] To ensure the accuracy of flow rate calculations within the operating range of the LFC using a temperature compensation method, the following calculation method is employed for density and viscosity adjustment. In the following formula, variables A, B, and C are determined by the physical dimensions of the system, which are here associated with the capillary.

[0052] Viscosity:

[0053] density:

[0054] When the pipes are arranged in a spiral configuration, deformation of the inner diameter of the capillary may be noticed.

[0055] In one example, computational fluid dynamics (CFD) modeling can be applied to the flow path at a selected location—for example, CFD modeling can be performed downstream of a second pressure sensor to examine turbulence in the flow.

[0056] The ring seal can be supplied by commercially available rings (e.g., rings supplied by VICI-Valco).

[0057] An example of the disclosed subject matter can be configured for use with a variety of liquids, including TEOS (tetraethyl orthosilicate or tetraethoxysilane), water, isopropanol, methanol, solvents, petroleum products, polymers, and biofluids.

[0058] In one example, the temperature can be controlled based on an output signal provided by the processor. For example, the temperature of the capillary, the temperature at the inlet end of the capillary, or the temperature at the outlet end.

[0059] Analysis of Q vΔP can reveal the differences when the downstream liquid flow is connected to a vacuum rather than being discharged into the atmosphere.

[0060] In one configuration, the capillary channel is insulated.

[0061] In one configuration, a syringe (plastic or non-plastic) is used to determine the response time.

[0062] Vacuum pumps can be configured to draw in air and expel air bubbles. Air bubbles in the line can affect response time.

[0063] In one example, bubbles are introduced into the system and their effect on the response time is measured. For instance, if bubbles are present in the capillary, changes can be monitored.

[0064] Flow rate is a function of temperature.

[0065] Q = f(ΔP)·(μ) 标准 / μ 实际 )

[0066] Q1=f(ΔP)·(μ 标准 / μ 实际 )

[0067] Q2=f(ΔP)·(μ 标准 / (μ 实际 +Δ))

[0068] Q1 / Q2=(μ 实际 +Δ) / μ 实际 =1+Δ / μ 实际

[0069] If μ 实际 If Δ = 1 and Δ = 0.01, then Q1 / Q2 = 1 ± 0.01

[0070] If μ 实际 If √(Q1 / Q2) = 0.8 and Δ = 0.01, then Q1 / Q2 = 1 ± 0.02

[0071] In one example of this subject matter, the apparatus is configured to operate a component in fluid communication with a capillary in series. The component may be located in the fluid path upstream or downstream of the capillary. Alternatively, the component may be in communication with the capillary in a parallel path.

[0072] A component, sometimes referred to as a control, can be a part that allows management of the flow rate of fluid through a capillary. This component can be a fluid pump used to pressurize the fluid. The pump can be a vane pump, diaphragm pump, piston pump, or other type of mechanical pump. In one example, the pump is driven by an electric motor, where the motor speed determines the pump flow rate or pump pressure, and the motor speed is determined by a signal from a processor. In various examples, the control includes a pump with variable pressure settings or bypass channels, and the signals delivered to the control allow variations in pump performance. In one example, the control includes a valve. The valve can be controlled by a signal from a processor. In one example, the control includes a variable orifice, and the signal from the processor can be configured to adjust or select the orifice size.

[0073] In one example, the control includes a thermal device. Therefore, the output signal from the processor can be configured to increase or decrease the heat energy delivered to the device.

[0074] In this example, the first temperature sensor and the second temperature sensor are each coupled to a corresponding end of the capillary. Additionally, the first pressure sensor and the second pressure sensor are also each coupled to a corresponding end of the capillary.

[0075] An interface may include a user-operable data input device. Examples of an interface may include a cursor control device (e.g., a mouse, trackball, touchpad), a keyboard, a touchscreen, and a microphone. Additionally, various instances of an interface may include a printer and a display screen. In one example, the interface includes a network interface configured to transmit data and instructions via a wired or wireless connection to a communication or data network.

[0076] In one example, the interface allows input of fluid parameters. Fluid parameters can include physical parameters such as fluid viscosity, fluid density, and fluid composition (including contaminants, particles, and other components).

[0077] In one example, the flow rate sensor is coupled to a capillary. The flow rate sensor can include a mass flow sensor, such as a Coriolis sensor. In various examples, the flow rate sensor can include: mechanically based sensors (e.g., turbine flow meters), pressure-based sensors (e.g., pitot tubes), variable area flow meters, optical flow meters, open channel flow meters, thermal mass flow meters, vortex flow meters, sonar flow meters, electromagnetic flow meters, ultrasonic flow meters, and optical flow meters. The flow rate sensor can provide a signal to a processor.

[0078] In one example, the processor executes an algorithm to receive sensor data (temperature, pressure, flow rate) and data characterizing fluid parameters. Based on the received data, the processor provides an output signal to the control. The output signal can be customized to achieve a specific flow rate or establish a specific temperature, pressure, or pressure differential associated with the capillary.

[0079] In one example, the processor executes an algorithm for receiving sensor data (temperature and pressure) and data characterizing fluid parameters. Control elements can be omitted, or the processor can operate in a fixed configuration. Based on the received data, the processor provides an output signal to determine the flow rate. The output signal can be tailored to provide an accurate flow rate based on received data regarding the temperature and pressure differential associated with the capillary. The flow rate can be indicated by a visible indicator.

[0080] In one example, the processor executes an algorithm to receive sensor data (temperature, pressure, and flow rate). Based on the received data, and when configured with a fixed or non-adjustable control element associated with the capillary, the processor provides an output signal corresponding to the selected fluid parameters. The output signal can be customized to provide data indicating fluid viscosity, fluid density, particle count, or another parameter. In one example, the output signal can be used for fluid identification or fluid matching.

[0081] In one example, the processor executes algorithms for receiving temperature sensor data, pressure sensor data, and flow rate data, as well as data characterizing fluid parameters. The pressure sensor data may be associated with sensors at a first end of the capillary, a second end of the capillary, or some other pressure data set. Based on the received data, and when a fixed or non-adjustable control element associated with the capillary is configured, the processor provides an output signal corresponding to the pressure difference. The output signal may be correlated with the pressure difference relative to a sensed pressure data received by the processor.

[0082] In one example, the processor executes algorithms for receiving temperature sensor data, differential pressure sensor data, and flow rate data, as well as data characterizing fluid parameters. The temperature sensor data may be associated with sensors at a first end of the capillary, a second end of the capillary, or some other temperature data source. Based on the received data, and when a fixed or non-adjustable control element associated with the capillary is configured, the processor provides an output signal corresponding to the temperature.

[0083] One objective includes measuring liquid temperature and liquid flow rate. This can be applied to both high and low flow rates. Various methods can be used to measure liquid temperature. Some costs associated with the direct measurement of liquid temperature are also considered. The relationship between flow measurement results and temperature can be noted. Accurate temperature measurement results can expand the operational range of flow measurement. One aspect of interest involves the flow rate that drives the temperature distribution.

[0084] One aspect of this subject involves measuring or controlling differential pressure to control flow rate. Fluid flow rate is affected by many factors, including various physical parameters of the fluid (e.g., viscosity, particle content, and density) and fluid temperature. In one example of this subject, a control component is configured to manage fluid flow rate. The control component may include a pump, valve, reservoir, or other device that affects fluid flow rate. In one example, an algorithm is executed by a processor to provide flow control or control of a device in fluid communication with a capillary, or to provide a measurement of the calculated value.

[0085] In one example, this topic includes a device that is calibrated at a first temperature and subsequently operated at another temperature. Examples in this topic provide interrelationships to allow the generation of calibration curves under both standard and non-standard conditions.

[0086] Various annotations

[0087] The foregoing description includes reference to the accompanying drawings, which form part of the detailed description. The drawings illustrate, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are also referred to herein as “examples.” Such examples may include elements other than those shown or described. However, the inventors also contemplate examples in which only those elements shown or described are provided. Furthermore, the inventors contemplate examples using any combination or substitution of those elements (or one or more aspects of those elements) shown or described with respect to a particular example (or one or more aspects of that particular example) or with respect to other examples shown or described herein (or one or more aspects of those other examples).

[0088] In the event of any inconsistency between the usage in this document and any other document incorporated by reference, the usage in this document shall prevail.

[0089] In this document, as is common in patent documents, the terms “a” or “an” are used to include one or more, and are unrelated to any other instance or use of “at least one” or “one or more.” In this document, unless otherwise indicated, the term “or” is used to mean a non-exclusive or, such that “A or B” includes “A but not B,” “B but not A,” and “A and B.” In this document, the terms “comprising” and “in…” are used as concise Chinese equivalents of the corresponding terms “comprising” and “wherein.” Furthermore, in the appended claims, the terms “comprising” and “including” are open-ended, meaning that a system, apparatus, article, composition, formulation, or process that includes elements other than those listed after such terms in the claims is still considered to fall within the scope of the claims. Additionally, in the appended claims, the terms “first,” “second,” and “third,” etc., are used only as designations and are not intended to impose numerical requirements on their objects.

[0090] Unless the context otherwise requires, geometric terms such as “parallel,” “perpendicular,” “circular,” or “square” are not intended to demand absolute mathematical precision. Instead, such geometric terms allow for variations due to production or equivalent functions. For example, if an element is described as “circular” or “generally circular,” the description still covers parts that are not precisely circular (e.g., slightly elliptical or polygonal parts).

[0091] The methods described herein may be implemented, at least in part, by a machine or computer. Some examples may include computer-readable or machine-readable media encoded with instructions operable to configure an electronic device to perform the methods described in the examples above. Implementations of such methods may include code, such as microcode, assembly language code, high-level language code, etc. Such code may include computer-readable instructions for performing various methods. The code may form part of a computer program product. Furthermore, in the examples, the code may be tangibly stored on one or more volatile, non-transitory, or non-volatile tangible computer-readable media, for example, during execution or at other times. Examples of such tangible computer-readable media may include, but are not limited to, hard disks, removable disks, removable optical discs (e.g., compact discs and digital video discs), magnetic tape cartridges, memory cards or memory sticks, random access memory (RAM), read-only memory (ROM), etc.

[0092] The above description is intended to be illustrative and not restrictive. For example, the examples (or one or more aspects of the examples) described above may be used in combination with each other. Other embodiments may be used by those skilled in the art after reviewing the above description. An abstract is provided to allow the reader to quickly determine the nature of the technical disclosure. The abstract is submitted under the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the specific embodiments described above, various features may be combined to simplify the disclosure. This should not be construed as meaning that all unclaimed disclosed features are necessary for any claim. Rather, the subject matter of the invention may lie in fewer than all features of a particular disclosed embodiment. Therefore, the appended claims are thus incorporated into the specific embodiments as examples or embodiments, wherein each claim is an independent, separate embodiment, and such embodiments are contemplated to be combined with each other in various combinations or substitutions. The scope of the invention should be determined by reference to the appended claims and the full scope of their equivalents.

Claims

1. A fluid system, comprising: A capillary tube having a first end and a second end; At least one temperature sensor is coupled to measure the temperature of at least one object selected from the wall of the capillary, to indirectly measure the temperature of a fluid flowing within the capillary, and coupled close to the fluid to directly measure the temperature of the fluid flowing within the capillary. A first pressure sensor is disposed at the first end; A second pressure sensor is disposed at the second end; A processor, coupled to the at least one temperature sensor, the first pressure sensor, and the second pressure sensor, wherein the processor is configured to execute instructions to determine flow control settings using the following: Based on at least a first temperature from the at least one temperature sensor, Based on the first pressure from the first pressure sensor Based on the second pressure sensor, and the second pressure, and Fluid parameters, received using an interface coupled to the processor, include at least one selected from fluid viscosity, fluid density, and fluid composition. The processor is coupled to a control in fluid communication with the capillary, the control being configured to implement the flow control settings, which, when implemented, change the fluid flow rate and provide a negative feedback signal, through which the device repeatedly collects data and readjusts the control to change the fluid flow rate.

2. The fluid system according to claim 1, wherein, The control includes at least one of a valve, a pump, and an orifice.

3. The fluid system according to claim 1, wherein, The interface includes a user-operable data input device.

4. The fluid system according to claim 1, wherein, The interface includes coupling to the network.

5. The fluid system of claim 1, further comprising a flow sensor coupled to the processor and fluidly coupled to the capillary.

6. The fluid system according to claim 5, wherein, The flow sensor includes a mass flow sensor.

7. A fluid system, comprising: A capillary tube having a first end and a second end; At least one temperature sensor is coupled to measure the temperature of at least one object selected from the wall of the capillary, to indirectly measure the temperature of a fluid flowing within the capillary, and coupled close to the fluid to directly measure the temperature of the fluid flowing within the capillary. A first pressure sensor is disposed at the first end; A second pressure sensor is disposed at the second end; A processor, coupled to the at least one temperature sensor, the first pressure sensor, and the second pressure sensor, wherein the processor is configured to execute instructions to determine an output corresponding to a measurement of mass flow rate within the capillary using the following: Based on at least a first temperature from the at least one temperature sensor, Based on the first pressure from the first pressure sensor Based on the second pressure sensor, and the second pressure, and Fluid parameters, which are received using an interface coupled to the processor. The processor is coupled to a control in fluid communication with the capillary, the control being configured to implement a flow control setting derived from the output, the flow control setting changing the fluid flow rate and providing a negative feedback signal, through which the device repeatedly collects data and readjusts the control to change the fluid flow rate.

8. The fluid system according to claim 7, wherein, The processor is coupled to a display, which is configured to provide a visible indication of the output.

9. The fluid system according to claim 7, wherein, The interface includes a user-operable data input device.

10. The fluid system according to claim 7, wherein, The interface includes coupling to the network.

11. A fluid system, comprising: A capillary tube has a diameter that is substantially smaller than the length of the capillary tube, and the capillary tube also has a first end and a second end; At least one temperature sensor is coupled to measure the temperature of at least one object selected from the wall of the capillary, to indirectly measure the temperature of a fluid flowing within the capillary, and coupled close to the fluid to directly measure the temperature of the fluid flowing within the capillary. A first pressure sensor is disposed at the first end; A second pressure sensor is disposed at the second end; A processor, coupled to the at least one temperature sensor, the first pressure sensor, and the second pressure sensor, is configured to execute instructions to determine the output using the following: Based on at least a first temperature from the at least one temperature sensor, Based on the first pressure from the first pressure sensor Based on the second pressure sensor, and the second pressure, and Based on the flow rate from a flow sensor coupled to the capillary, the output corresponds to parameters of the fluid in the capillary, including at least one selected from fluid viscosity, fluid density, and fluid composition. The processor is coupled to a control in fluid communication with the capillary, the control being configured to implement a flow control setting derived from the output, the flow control setting changing the fluid flow rate and providing a negative feedback signal, through which the device repeatedly collects data and readjusts the control to change the fluid flow rate.

12. The fluid system according to claim 11, wherein, The flow sensor includes a mass flow sensor.

13. The fluid system according to claim 11, wherein, The processor is coupled to a display, which is configured to provide a visible indication of the output.

14. A fluid system, comprising: A capillary tube having a first end and a second end; At least one temperature sensor is coupled to measure the temperature of at least one object selected from the wall of the capillary, to indirectly measure the temperature of a fluid flowing within the capillary, and coupled close to the fluid to directly measure the temperature of the fluid flowing within the capillary. A second temperature sensor is coupled to the capillary at the second end; A first pressure sensor is disposed at the first end; A processor, coupled to the at least one temperature sensor, the first pressure sensor, and the second temperature sensor, wherein the processor is configured to execute instructions to determine the output using the following: Based on at least a first temperature from the at least one temperature sensor, Based on the first pressure from the first pressure sensor Fluid parameters, received using an interface coupled to the processor, include at least one selected from fluid viscosity, fluid density, and fluid composition. Flow rate, received from a flow sensor in fluid communication with the capillary. The output corresponds to the pressure differential associated with the first pressure and is used to determine the flow control settings; and The processor is coupled to a control in fluid communication with the capillary, the control being configured to implement the flow control settings, which, when implemented, change the fluid flow rate and provide a negative feedback signal, through which the device repeatedly collects data and readjusts the control to change the fluid flow rate.

15. The fluid system according to claim 14, wherein, The interface includes a user-operable data input device.

16. The fluid system according to claim 14, wherein, The interface includes coupling to the network.

17. The fluid system according to claim 14, wherein, The flow sensor includes a mass flow rate sensor.

18. The fluid system according to claim 14, wherein, The flow sensor includes a volumetric flow rate sensor.

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