1. Summary

Intelligent vortex precession flow meter is a new gas flow meter with the leading domestic level which is developed by our company. The flow meter has a combination function of flow, temperature and pressure detection. It also has the function of temperature, pressure and compression factor automatic compensation. It is the ideal instrument that is used for gas metering in petroleum, chemical industry, electric power, metallurgy and other industries.

Intelligent vortex precession flow meter can be widely used in the measurement of various gas flow in Petroleum, chemical industry, electric power, metallurgy, urban gas supply and other industries. It is the preferred product for the transmission and distribution measurement and trade measurement of natural gas in oil field and city.

3. Main technical parameters and functions

3.1 Flow meter specifications, basic parameters and performance indicators (See table 1)

(Table 1)

Note: 1.Accuracy: the system accuracy after temperature and pressure correction;

3.2 Standard condition：P=101.325KPa，T=293.15K

3.3 Conditions of use：

ambient temperature：-30℃～+65℃

relative humidity：5%～95%

medium temperature：-20℃～+80℃

atmospheric pressure：86KPa～106KPa

3.4.1 Working power supply：

A．External power supply：＋24VDC±15%，ripple＜5％，

Apply to 4～20mA output, pulse output, alarm output、RS-485 and so on；

B．Internal power supply：A set of 3.6V lithium battery（ER26500）. When the voltage is lower than 3.0V, display under voltage.

3.4.2 Overall power consumption：

A．External power supply：<2W;

B．Internal power supply: average power consumption 1mW，can be used continuously for more than two years.

3.4.3 Pulse output mode：

A．Pulse signal of working conditions. Amplify and output the pulse signal of working conditions that is detected by the flow sensor through photon coupled isolator directly. High level≥20V，Low level≤1V；

B． Calibration pulse signal. Matching with IC card valve controller. High level range≥2.8V，Low level range≤0.2V， The settable range of the unit pulse representative volume: 0.001m³~100m³. Must pay attention to when choosing this value：calibration pulse signal frequency should≤1000Hz;

C．Calibration pulse signals are amplified and outputted through photon coupled isolator. High level≥20V, low level≤1V.

3.4.4 RS－485 Communication（Photoelectric isolation），can achieve the following functions：

A．Using RS-485 interface, can be directly connected to the host computer or the secondary meter, and remote display the medium temperature, pressure, as well as the standard volume flow and the total standard volume compensated by temperature and pressure;

B．By matching the RS－485 interface with the HW－Ⅰ data collector, can form a telephone network communication system. A data collector can drive 15 flow meters;

C．By matching the RS－485 interface with the HW－Ⅱ data collector, can form a broadband network communication system. Transmit data by INTERNET. A data collector can drive 8 flow meters;

3.4.5 4～20mA standard current signal（photoelectric isolation）

Directly proportional to the standard volume flow. 4mA corresponds to 0 m³/h, 20mA corresponds to the maximum standard volume flow (the value can be set in the first level menu). Standard: two-wire system or three-wire system. Flow meter can identify automatically according to the inserted current module, and output correctly.

4. Type selection and installation

4.1 Flow meter type selection

There are two principles should be grasped in the selection process: firstly, ensure production safety. Secondly, ensure the accuracy of use. Therefore, three selection parameters must be implemented: the maximum, minimum and commonly used flow of short term and long term (mainly used for selecting the inside nominal diameter of meter ); design pressure of the measured medium (mainly used for selecting the nominal pressure rating of meter); actual working pressure (mainly used for selecting the pressure level of the pressure sensor of meter)

a. When the known measured flow is the working condition volume flow, the suitable inside nominal diameter can be directly selected according to the flow range in the table.

b. When the known measured flow is the standard condition volume flow, the standard condition volume flow Q_Nshould be converted into the working condition volume flow Qv, and then select the corresponding inside nominal diameter according to the flow range in the technical parameter list;