Ultrasonic Flowmeters for Accurate Flow Measurement
General information
The ultrasonic flow meter, URSV-010M, is a state-of-the-art instrument designed for precise measurements of average volume flow and volume of diverse liquids. It is suitable for measuring liquids such as hot, cold, and waste water, oil, fuel oils, aggressive liquids, liquid food products, and more. The instrument uses electro-acoustic transducers (PEA) that can be installed via mortise or clamp-on in both metal and plastic pipelines. This ultrasonic flow meter provides reliable and accurate measurements in different operating conditions, including hazardous areas. It is a non-intrusive and user-friendly meter that doesn't require any modification to the pipe or fluid being measured. The URSV-010M is easy to install, and it displays the real-time flow rate and total volume of fluid that has passed through the meter.
Symbol structure
The URCV-010M is a versatile and customizable device used for measuring the flow rate of various liquids in different pipelines. This device comes in different configurations, each designed for specific purposes.
URCV-010M-001 is designed with an overhead PEA that can be installed without opening the production pipeline. This feature is particularly useful for situations where the pipeline cannot be opened, such as in hazardous areas.
URCV-010M-002 comes with a mortise PEA that is installed with the opening of the production pipeline. This configuration is ideal for situations where it is necessary to have direct contact with the liquid being measured.
URCV-010M-011 is designed with a primary flow converter (PP) installed on the production pipeline and made with a patch PEA. This configuration is suitable for applications that require accurate and consistent measurements.
URCV-010M-012 comes with a PP installed on the production pipeline and made with cut-in PEA, placed along the diameter or chord. This configuration is ideal for applications where there is limited space for installation.
URCV-010M-003 is designed with PP installed on the production pipeline and made with mortise PEA placed along the flow axis of the U-shaped measuring section. This configuration is suitable for measuring the flow of aggressive liquids.
URCV-010M-013 is similar to URCV-010M-003, but with a corrosion-resistant measuring section (DUT). This configuration is ideal for measuring the flow of corrosive liquids.
Overall, the URCV-010M device is a versatile and reliable solution for measuring the flow rate of different liquids in various pipelines. Its different configurations make it suitable for different applications, ensuring that users can find the right solution for their needs.
terms of Use
The terms of use for the flow meter-counter of ultrasonic "Rise-Off RS" (URCV-010M) are crucial for maintaining its efficiency and accuracy. The secondary measuring transducer (VP) and power supply (IEP) can operate smoothly in ambient temperatures ranging from 5 to 50°C. However, the electro-acoustic transducers (PEA) can function at a wider temperature range, from minus 60 to 200°C. The relative humidity of the ambient air should not exceed 80% at a temperature of 35°C for VP and IEP, while for PEA, it can reach 100% at a temperature of 40°C and below with moisture condensation.
The flow meter-counter has resistance to climatic factors of B4 (VP, IEP) and D2 (PEA) according to GOST 12997-93, and resistance to atmospheric pressure of P2 according to the same standard. It also has resistance to mechanical stress of N2 (VP, IEP) and V3 (PEA). The flow meter-counter has a group of explosion-proof electrical equipment for overhead and mortise PEA II according to GOST 22782.3-77 with a special type of protection according to GOST 12.2.020-76. The device has a degree of protection against ingress of dust and moisture of IP54 (VP, IEP) and IP67 (PEA) according to GOST 14254-96.
Specifications
The flow meter-counter is registered in the State Register of Measuring Instruments under No. 16179-97. Its specifications include a supply voltage of 36+7 V from a single-phase AC network or 220+44 V from DC sources. The single-phase AC network frequency is 50+1 or 400+8 Hz, and its power consumption is not more than 15 VA. The nominal diameter of the pipeline Du ranges from 10-4200 mm for mortise PEA and 50-4200 mm for overhead PEA. The flow meter-counter can measure the average fluid volume flow of various liquids, including hot, cold and waste water, oil and oil products, aggressive liquids, and liquid food products, etc. The device can measure fluid volume flow from minimum Qmn - 0.0002 Du(2) to maximum Qmax - 0.03 Du(2). The maximum pressure in the pipeline is 2.5 MPa, and the temperature of the measured liquid ranges from -10 to +180°C.
The length of the signal cable between the VP and PEA should not exceed 100 m, and the length of the straight section of the pipeline for installation should be at least (3-40)Du before the first PEA in the flow and (1-5)Du after the second PEA in the flow. The flow meter-counter supports information transfer rate via RS-communication of 75-38,400 kBaud, and it has a storage time of archive information when disconnected external power supply of at least 1 year. The weight of the VP is 5 kg, while the patch PEA and mortise PEA weigh 0.5 kg and 1 kg, respectively. The power supply weighs 1.2 kg, and the overall dimensions are VP - 257x384x125 mm, patch PEA - 88x31x43 mm, mortise PEA - Zh 55x123 mm, and power supply - 160x80x120 mm. The flow meter-counter has a mean time between failures of 75,000 h and an average service life of 12 years.
In the world of fluid flow measurement, a flow meter plays a vital role by providing accurate output of measured volume values. This output is generated in the form of pulses with a normalized mass ranging from 0.0001 to 100.0 m3/imp.
But that's not all; the flow meter also provides the measured flow rates output in the form of a DC signal, with different limits based on the load resistance. These limits are from 0 to 5 mA at a load resistance of not more than 1.5 kOhm, from 0 to 20 mA at a load resistance of not more than 250 kOhm, and from 4 to 20 mA at a load resistance of not more than 250 kOhm.
The archives of the flowmeter also add to its functionality. The flow meter has a capacity for hourly, daily, monthly, managed, emergency situations, and failure archives. The hourly archive stores data for the last 728 hours, the daily archive for the last 64 days, and the monthly archive for the last 64 months. The managed archive stores 960 entries, while the emergency situations archive and failure archive store 128 and 64 entries, respectively.
The flow meter measures and indicates the values of various parameters, including the average volume flow in any direction of fluid flow, liquid volumes on a cumulative total for each flow direction, fluid flow rate in any direction of fluid flow, current date and time, flowmeter operation time in the presence of emergency situations, and flowmeter shutdown time in the presence of failures.
One of the flow meter's standout features is its ability to operate in volume dosing mode. The flow meter accumulates the set volume value and activates the relay output once it's reached.
Furthermore, the flow meter provides archiving in non-volatile memory and output to the display device. It stores measured values of volumes in standard archives: hourly, daily, monthly, and a managed archive with a set archiving interval. Additionally, it has an archive of failures and abnormal situations, indicating the type of event, date and time of its start, and duration.
The functional diagram of the flowmeter is shown in Figure 1, highlighting its various components and how they work together to provide accurate and reliable fluid flow measurements.
The functional diagram of a flowmeter is crucial for understanding how it operates. The flowmeter consists of several key components, including a keyboard, control device, meter, VP, LCD, and secondary power sources.
The meter is the heart of the flowmeter, responsible for controlling the process of variable sensing of liquid flow in the pipeline. The meter uses ultrasonic vibrations to measure the difference between the propagation times of the liquid flow along and against the pipeline.
In addition to measuring the flow of liquid, the meter determines other key parameters, including the values of the measured parameters of the fluid flow, and generates an output signal proportional to the fluid flow in the pipeline.
The flowmeter also comes with various output options, including a current output (TV), pulse output (IV), and a relay output (Ð Ð’). These outputs allow the flowmeter to communicate with a personal computer (PC) via RS232 and RS485, and control the operation of pulse and relay outputs.
The control device serves to receive signals from the keyboard and issue control signals to the meter. Using the keypad, users can select an operating mode, input installation data, and choose the menu and indication window on the LCD display.
The LCD display is a liquid crystal illuminated panel that allows for the display of numbers, letters, and various characters. It is essential for providing information output to the user.
The flowmeter is powered by an AC power supply, which reduces the single-phase voltage of the primary network 220 V 50 Hz to a voltage of 36 V 50 Hz. The secondary power sources then convert the power supply of the VP into the required DC voltage.
The flowmeter can also be powered without an IED using single-phase voltage 36 V 50/400 Hz or DC voltage 50V. With these components working together, the flowmeter can perform periodic self-diagnostics, calculate the operating time in the presence of emergency situations, and the stop time of the flowmeter in the presence of failures.
Scheme of electrical connections of the flowmeter:
1 - VP;
2 - power supply;
AIV - active pulse output;
TV - current output;
Ð Ð’ - relay output;
PIV - passive pulse output;
ХР1 - communication connector via RS232 interface;
XP2 - connector for connecting the VP power cable;
X4 - terminal block for PEA connection;
X7 - terminal block for connecting external connections;
XS1 - control connector
The RS232 interface is designed to provide direct or modem communication with an IBM compatible PC.
The RS232 interface provides direct communication between a PC and only one flowmeter with a communication line length of up to 15 m. Communication using a modem over a telephone line or radio channel can be carried out over any distance.
The RS485 interface, which the heat meter is equipped with upon request, allows direct communication in a network of 32 subscribers at a distance of up to 1200 m. The
flow meter has the ability to connect external devices to a passive pulse output.
The relay output is activated when one of the assigned types of events occurs. If all assigned events stop, the output contacts open.
The flow meter has two operating modes: operational mode (user mode) and service mode (setup and verification mode of the device).
In the operating mode, the current and archive values of the measured parameters are displayed on the LCD and the corresponding information is output to the available information outputs: RS232, RS485, pulse, current, relay.
In the service mode, the ability to set or change the parameters of the flowmeter state (during commissioning) is added using the keyboard and LCD, and it also provides the ability to check the device.
The output of information on the VP display and the input of parameters of the state of the flow meter is organized using a system of functional menus and display windows.
The function menu system consists of eight menus that can be reversed using pushbuttons.
List of functional menus:
1 - current measurement results;
2 - work log; 3 - volume archive;
4 - main parameters of the state;
5 - cleaning archives; 6 - operating mode;
7 - auxiliary state parameters;
8 - verification parameters of the state.
The general view of the VP flowmeter is shown in fig. 3.
General view and overall dimensions of the VP flowmeter:
1 - screws fixing the cover of the lower compartment;
2 - membrane keyboard;
3 - LCD display;
4 - screws fixing the cover of the upper compartment;
5 - upper compartment VP;
6 - the lower compartment of the VP;
7 - fastening elements of the VP at the facility;
8 - cable glands for PEA signal cables;
9 - cable gland of external communications;
10 - pressure cable entry of the power cable;
11 - protective earth terminal
In the design of this device, the body is made of a durable aluminum alloy and is shaped like a box with two compartments. The bottom panel of the box is equipped with grounding clamps, cable glands for the power cable, cables for external connections, and PEA signal cables. The rear wall of the box is fitted with fastening elements for VP at the site of operation.
Inside the box, there is a device board that houses circuits for generating electrical pulses for PEA excitation and receiving signals from PEA. The microprocessor with shapers of the output signals for external connections, non-volatile memory circuit, and secondary power supplies are also housed inside the box. Communication with the indicator and keyboard is facilitated through a flat multicore cable.
The lower compartment houses the switching and adjusting elements. The overhead PEAs are constructed in a rectangular case with a radiating surface at the lower edge. A mark on the side surface of the PEA indicates the position of the acoustic center of the PEA. The PEA is sealed by pouring a heat-resistant electrical insulating compound for durability and reliability.
Overall, the device is built with robust materials and designed to withstand harsh operating conditions. Its specialized components, such as the non-volatile memory circuit, microprocessor, and PEA signal cables, enable precise measurements and efficient communication with other devices. The compact and sturdy construction of the device allows for easy installation and operation, making it an ideal choice for a variety of industrial applications.
When it comes to ultrasonic flow meters, there are two types of electroacoustic transducers: overhead PEA and mortise PEA. The overhead PEA is mounted on the external surface of the pipeline, while the mortise PEA is a cylindrical structure with a disk radiating surface that is installed by opening up the pipeline and attaching it using a welded mounting pipe. The mortise PEA comes with a coaxial RF cable with a connector for extending the communication cable with the VP.
The flowmeter is a time-pulse ultrasonic flowmeter that measures the difference in the transit time of probing pulses of ultrasonic vibrations in the direction of fluid flow in the pipeline and against it. The probing pulses are excited by electroacoustic transducers. The flowmeter belongs to autocirculation flowmeters with alternate switching, which is characterized by the alternating operation of two synchro rings. The primary flow transducer includes a pipe section and two electroacoustic transducers fixed on it, PEA1 and PEA2, which provide radiation and reception of ultrasonic signals into the liquid at an angle to the pipeline axis.
The secondary measuring transducer carries out alternate radiation into the moving liquid and reception of USS, as well as measurement of the time difference of USS propagation along and against the fluid flow. To select the standard size of the measuring section or PP, it is necessary to know the range of liquid flow rates in the pipeline. The flow range in the pipeline must correspond to the flow range for a given DN.
PEA (PP) can be installed on vertical, horizontal, and inclined pipelines and does not require installation of a filter in the pipeline. It is recommended to install PEA (PP) on a horizontal pipeline in such a way that the plane passing through both PEA and the axis of the pipeline is located at an angle of approximately 45° to the vertical. The delivery set includes a secondary measuring transducer, power supply, electro-acoustic transducer, measuring section, signal cables for PEA, a set of mounting parts, and technical documentation.
For the installation of PEA, there are three schemes: Z-scheme, V-scheme, and W-scheme. The installation of PEA according to the Z-scheme is shown in figure 6, which includes the pipeline, the direction of flow in the pipeline, corresponding to the positive sign of the flow rate, and the PEA installation. If the Dn value of the selected standard size of the IU (PP) is less than the Dn value of the pipeline, then transitional cones (confuser and diffuser) are used for installation in the pipeline. The hydraulic losses increase with the use of transitional cones, but it ensures more stable operation.
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