Patent Application
20200209025
The present invention is directed to flowmeters.
In many developed countries, flowmeters are used to measure the volume of water used by residential and commercial buildings that are supplied with water by a public water supply system, and for other applications in agriculture and in industry. Flowmeters can also be used at a water source or throughout a water system to determine flow through a particular portion of the system, either for billing purposes of as part of a metering/control system. There are several types of flowmeters: positive displacement flowmeters, velocity meters, mechanical or electronic types such as electromagnetic meters, and ultrasonic meters.
An ultrasonic flowmeter is a type of flowmeter that measures the velocity of a fluid using ultrasound to calculate the volumetric flow. Using ultrasonic transducers, the flowmeter can measure the average velocity along the path of an emitted beam of ultrasound, by calculating the difference in transit time between the pulses of ultrasound propagating with and against the direction of the flow or, in some cases, by measuring the frequency shift of signals reflected from particles within the flow from the Doppler Effect.
Sometimes water meters are used in conjunction with other components to form a system. Conventional water systems that employ ultrasonic flowmeters in wired connection to other system components are prone to various hazards, such as weather damages, rodents' damages, wear damages and the like, due to the physical connection between the flowmeters and other elements of the system. Furthermore, replacing elements of conventional water systems requires recalibration of the flowmeter each time.
The present invention provides a flowmeter for measuring the volume of a fluid passing through a flow path, in some cases combined with control components for controlling a system.
Thus, according to an embodiment of the present invention there is provided an apparatus integrating a flowmeter and a controller for a system including at least one wirelessly controllable flow-control device, the apparatus comprising: a body defining a fluid flow path from an inlet to an outlet; a fluid flow sensor mechanically associated with the body and configured to generate a signal sufficient to allow derivation of a rate of fluid flow along the flow path; a wireless communications interface mechanically associated with the body and configured for communicating with the at least one wirelessly controllable flow-control device; and a processing system, mechanically associated with the body, comprising at least one processor and a data storage device, the processing system being in communication with the sensor and the wireless communications interface, the processing system being configured to: derive from the signal a volume of the fluid passing along the flow path; and, generate control signals to be transmitted by the wireless communications interface for actuation of the at least one wirelessly controllable flow-control device according to a program.
According to a further feature of an embodiment of the present invention, the fluid flow sensor comprises an ultrasonic transducer configured to transmit an ultrasonic signal into fluid within the flow path; and an ultrasonic transducer configured for receiving the ultrasonic signal after passing through the fluid.
According to a further feature of an embodiment of the present invention, there is also provided: at least one electrically controlled valve controlling flow along a flow path supplied via the flowmeter; at least one additional device selected from the group consisting of: a sensor, a pump and a greenhouse environment controller; and wireless communications components providing wireless communication between the electrically controlled valve, the at least one additional device and the controller.
According to a further feature of an embodiment of the present invention, the wireless communications interface uses a form of communication selected from the group consisting of: Bluetooth communication, GPRS communication, cellular communication and the combination thereof.
According to a further feature of an embodiment of the present invention, the program is defined in part by at least one volume of fluid to be delivered as derived by the processing system.
There is also provided according to the teachings of an embodiment of the present invention, a flowmeter comprising: a body defining a fluid flow path from an inlet to an outlet; a fluid flow sensor configured to generate a signal indicative of a rate of fluid flow along the flow path, the fluid flow sensor comprising: an ultrasonic transducer configured to transmit an ultrasonic signal into fluid within the flow path, and an ultrasonic transducer configured for receiving the ultrasonic signal after passing through the fluid; and a processing system comprising at least one processor and a data storage device, the processing system being in communication with the sensor, the processing system being configured to: derive from the signal a flow rate of the fluid passing along the flow path; when the flow rate exceeds a threshold flow value, to integrate the flow rate to determine a volume of the fluid that has passed along the flow path; and, at least when the flow rate is below the threshold flow value, to generate an output indicative of a detected fluid flow along the fluid flow path.
According to a further feature of an embodiment of the present invention, there is also provided a graphic display screen associated with the body and in communication with the processing system, wherein the output is generated as a visual indication on the graphic display screen of the detected fluid flow.
According to a further feature of an embodiment of the present invention, the output is generated as an alert transmitted to a remote location.
According to a further feature of an embodiment of the present invention, the processing system is in communication with a wireless controller.
According to a further feature of an embodiment of the present invention, the processing system is further configured to identify at least one condition selected from the group consisting of: a faulty flow-control device, a leak, a blockage, and presence of air bubbles.
There is also provided according to the teachings of an embodiment of the present invention, a flowmeter comprising: a body defining a fluid flow path from an inlet to an outlet; a fluid flow sensor configured to generate a signal indicative of a rate of fluid flow along the flow path, the fluid flow sensor comprising: an ultrasonic transducer configured to transmit an ultrasonic signal into fluid within the flow path, and an ultrasonic transducer configured for receiving the ultrasonic signal after passing through the fluid; a non-volatile memory chip permanently mechanically integrated with the body, the non-volatile memory chip storing calibration data for the flowmeter; and a processing system comprising at least one processor and a data storage device, the processing system being in communication with the sensor and the non-volatile memory chip, the processing system being configured to: read from the non-volatile memory chip the calibration data; and derive from the signal and the calibration data a volume of the fluid passing along the flow path.
Some embodiments of the present invention are herein described, by way of example only, with reference to the accompanying drawings. With specific reference to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of embodiments of the invention. In this regard, the description taken with the drawings makes apparent to those skilled in the art how embodiments of the invention may be practiced.
Attention is now directed to the drawings, where like reference numerals or characters indicate corresponding or like components. In the drawings:
The present invention is an apparatus including a flowmeter for measuring the volume of a fluid passing through a flow path, and which, according to a first aspect of the invention, integrates such a flowmeter with a controller that generates control signals for actuation of components in communication with the apparatus based on the fluid volume measurement and/or elapsed time. According to a further aspect of the present invention, an ultrasonic flowmeter is provided with an embedded non-volatile memory chip which is a fixed part of the flowmeter mechanical structure, and which interfaces with replaceable electronic components to provide calibration data for the flow characteristics of the particular mechanical structure, each of which has its own individual flow properties, due to manufacturing tolerances and variations in the flow channel. These two aspects may be used independently, or can be used to particular advantage synergistically in a single system, as will be exemplified herein below.
Although the invention will be exemplified throughout the description by reference to a flowmeter, it should be noted that the teachings of the invention are not inherently limited to the context of systems conveying only water, and the invention can equally be used to advantage in various systems which deliver or otherwise control the flow of a range of liquids including but not limited to, potable water, recycled water and other irrigation-grade water, waste water, seawater, other water-based solutions, and various non-aqueous liquids such as petroleum derivative products.
The principles and operation of the apparatus according to the present invention may be better understood with reference to the drawings and the accompanying description.
According to certain particularly preferred implementations, the processing system 106 is in communication with a wireless communications interface 112. The wireless communications interface 112 is, according to certain preferred but non-limiting implementations, mechanically associated with body 102 and is configured for communicating wirelessly with other controllable components, typically including at least one flow-control device, such as a valve or, in some cases, an additive delivery pump for adding fertilizer and/or other additives to the water supply. The communication can be formed using different forms of communication, close and long, for example, Bluetooth communication, GPRS communication, cellular communication, cloud-based monitoring and the like. The processing system 108 derives the volume of the fluid passing along the flow path from the signal generated by the fluid flow sensor 104 and then generates control signals to be transmitted by the wireless communications interface 106 for actuation of, or other communication with, components that are in communication with it, such as temperature sensors, air humidity sensors, soil moisture sensors, volume sensors, drippers, sprinklers, valves, water systems, greenhouse environment controllers such as automatic blinds or fans, etc. The actuation of these components can also be carried out using a schedule stored in a data storage device 114 that is configured for storing executable instructions, such as operation schedules and the like. In some preferred cases, the schedule or program may use the measured water flow as a parameter in an algorithm for determining how to operate the flow-control device(s).
A further aspect of the present invention addresses a shortcoming which is common to a range of different digital flowmeters, particularly including but not limited to an ultrasonic flowmeter such as the example illustrated in the accompanying drawings, or a magnetic flowmeter. Ultrasonic and magnetic flowmeters do not require a flow-obstructing mechanism to be deployed in the flow path, and therefore benefit from low pressure losses and are suitable for high flow rates. On the other hand, ultrasonic and magnetic flowmeters have limited accuracy for very low flow rates, and are typically certified (i.e., considered reliably accurate) only down to a “threshold flow” lower flow rate limit. Flow rates below that threshold flow are not accurately measured, and are generally not recorded.
Because of this disregard for below-threshold flow rates, it can be difficult to identify certain fault conditions, such as when there is a slow flow via a faulty valve or a slow leak from a piping system. Digital flowmeters such as the aforementioned ultrasonic flowmeters disregard such low flow rates. It may therefore be impossible to detect a fault which gives rise to a below-threshold flow rate.
According to a further aspect of the present invention, the processing system actuates the display of the flowmeter device to generate an indication of water flow, and preferably also the flow direction, either continuously under all flow conditions or under predefined flow conditions, particularly below-threshold flow rates. Although such slow flow rates are not reliably measured in quantitative terms for metering purposes, a flow sensor such as the ultrasonic flow sensor described herein or a magnetic flow sensor can reliably distinguish between zero flow conditions and sub-threshold flow rates down to an order of magnitude or more below the threshold flow rate. Most preferably, the indication of water flow is a time-varying indication, such as a moving arrow, or a flashing arrow, or a symbol in which all or part of the symbol appears and disappears to give an impression of motion. One such example is illustrated in
In addition to the display of trickle-flow conditions, the water flow measurement data is preferably used by the processing system with various different logic algorithms to identify various error conditions that may interfere with the operation of the apparatus 100 and/or require user intervention. By way of example, the system may identify faulty valves by the failure of flow rates to change as and when expected in response to a valve operation instruction, may identify leaks by small residual flow rates under what should be zero flow conditions of the system, and can identify blockages by the system reaching lower-than-expected peak flow when a given valve is opened. Each of these error detection features is believed to be of value in its own right.
An additional, or alternative, feature that may be provided particularly in the case of an ultrasonic flowmeter is detection of the presence of air bubbles in the flow path. Air bubbles can be detected by abrupt changes in the ultrasound transmission properties between the transducers. In such cases, the processing system preferably adjusts the valve opening times to compensate for the period that air bubbles were passing through the flowmeter, so as to ensure that a desired quantity of water is actually delivered to the appropriate outlets.
The apparatus 100 can be operated using various energy sources, such as batteries, solar panels or an AC source, alone or any combination of power sources. The apparatus 100 may include a graphic display screen associated with body 102. The graphic screen is in communication with processing system 106, which activates the screen to display a visual identification of the flowmeter output, including the cumulative water flow data, and preferably also any trickle-flow condition of fluid flow along the fluid flow path, as described above. Where the device also operates as a controller for a water flow management system, as described herein, the display may advantageously be subdivided into two regions, or a second distinct display panel may be provided, which provides status information about the water flow management system operation and/or provides part of a user interface to allow adjustment of settings for operation of the water flow management system.
Since the electronic components of the flowmeter are more prone to damage, both by natural causes and through mechanical damage, than the main body of the flowmeter, it is desirable that it should be possible to replace some or all of the electronic components with minimum disruption to the flowmeter's operation. In order to allow prompt return to operation of the flowmeter with minimum disruption, according to an aspect of the present invention, a calibration data storage component that stores the calibration data of the flowmeter in such a way that it will be protected from environmental or mechanical damage, and allows quick and efficient replacement of damaged electronic components, without having to remove the flowmeter from the pipeline for calibration at a certified laboratory.
According to a further aspect of the present invention, which may be used to advantage in an otherwise conventional flowmeter, but is particularly valuable when used in synergy with the other features of apparatus 100 described herein, the apparatus 100 includes a non-volatile memory chip permanently mechanically integrated with body 102. The chip stores calibration data for apparatus 100 and is in communication with processing system 106 (which may be the dual-purpose flowmeter and controller processing system described above, or a conventional flowmeter processing system, according to the application). The processing system 106 reads the calibration data from the chip and derives a volume of the fluid passing through the flow path by combining the data with the signal from the fluid flow sensor 104. The chip is integrated with the metal structure of the body 102, preferably within a recess in the body filled with a waterproof filling compound so as to permanently fix the chip, typically with an electrical connector projecting from the recess.
It will be appreciated that the present invention is not limited to this particular implementation of the ultrasound measurement technique, and is equally applicable to any and all ultrasound flowmeter sensing techniques, such as those measuring flow based on Doppler shift, as well as magnetic flowmeters based on inductive effects of a water flow and any and all other flow measurement techniques.
While the invention has been described with respect to a limited number of embodiments, it will be appreciated that many variations, modifications and other applications of the invention may be made. Therefore, the claimed invention as recited in the claims that follow is not limited to the embodiments described herein.
