ICARUS ELECTRONIC GAS VOLUME CONVERTER

Transcription

1 ICARUS ELECTRONIC GAS VOLUME CONVERTER 1. INTRODUCTION 2. TECHNICAL DETAILS ICARUS is an electronic volume converter which, combined with a gas meter, provides the gas measurement in Sm3, calculated at base conditions of + 15 C and 1,01325 bar. 2.1 Pressure Measurement ICARUS fully conforms to all current European standards and directives, such as EN and ATEX 94/9/EC, and is certified according to MID n 2004/22/EC. ICARUS is a type 1 device, manufactured with integrated pressure and temperature sensors. ICARUS is always fitted with an external piezo-resistive absolute pressure sensor, connected to the processing unit by a cable whose typical lenght is 3 mt. The sensor is enclosed in a stainless steel casing. The connection is G ¼, flat sealing. Available full scale ranges: 2,5; 6; 10; 30; 81 bar A Accuracy: 0,1% of the full scale. info@fimigas.it

2 2.2 Temperature Measurement ICARUS is always provided with a 4 wires PT 1000 sensor compliant with European Standard EN IEC (its resistance value is 1000Ω at 0 C). 4 wires connection grants a high accuracy measurement despite cable resistance. The sensor is connected to the processing unit by a cable whose typical lenght is 3 mt. The operating measuring range of the sensor is -30 C 70 C. 2.3 Signal inputs ICARUS has an Open Collector highfrequency input and a low-frequency pulse input. When connected to a LF pulse emitter, gas meter pulses are divided by a pulse weight factor [pulse/m 3 ] which is set in the device. When Icarus is connected to a HF gas meter, its Open Collector HF input must be configured specifying: - The pulse weight factor. - The frequency value of the pulse train corresponding to the maximum flow rate. The maximum frequency that can be read by the input is 5Khz. HF input can operate only if ICARUS is powered by an external main DC voltage supply. 2.4 Conversion function Referring to ISO European Standard, ICARUS operates togheter with a gas meter to convert the measured gas volume into base conditions, according to the following formula: Vb = Vm C N 4 different algorithms for the calculation of compressibility: - SGERG 88 - AGA8 Gross 1 - AGA8 Gross 2 - AGA NX Outputs - N 1 optical serial port to communicate with a local PC (configuration setup, data download). - N 1 RS 232 serial port to connect to an external GSM/GPRS modem, necessary to achieve remote transmission of stored data for tele-reading applications. - N 1 RS 485 serial port, used or to communicate with a DCS by MODBUS RTU protocol, or to connect to an external GSM/GPRS modem, necessary to achieve remote transmission of stored data for telereading applications. - N 2 pulse outputs to transfer volume pulses associated to internal counters, or the presence of an alarm in the device. - N 1 PWM (pulse with modulated) output, by which it s possible to have a 4-20 ma output associated to a parameter (temperature, pressure or flow-rate), thanks to an external converter that, located in safe area, converts the PWM signal into 4-20 ma format. - N 1 LAN connection by ethernet port and n ma outputs available on request. 2.6 Flow-rate calculation ICARUS can calculate both measured flowrate and base flow-rate (instantaneous or average flow-rate). The instantaneous flow-rate at measured gas conditions (Qm) is calculated by counting the number of read pulses and measuring the time elapsed since the last calculation (minimum time 15 seconds). The instantaneous flow-rate at base gas conditions is calculated thanks to the following formula: Qb = Qm x C The average flow-rate Qb e Qm (stored every 15 minutes) is calculated according to Standard UNI TS

3 2.7 Keypad 2.9 Power The keypad is composed of five keys: - Four directional arrow shaped keys (Up, Down, Left, Right directions). - One confirmation central key (OK). Up/Down direction keys let the user: - Scroll up/down the items in a menu page. - Move the cursor of the display from one line to the upper/lower one. Left/Right direction keys let the user: - Return to the previous menu page. - Move the cursor of the display leftwards/rightwards. OK key is used: 2.8 Display - To select a menu item. - To confirm a parameter setup. The display of ICARUS lets the user: - Visualize real time gas data. - Visualize historical gas data. - Visualize active alarms on the device. - Visualize/modify setup. - Calibrate pressure and temperature sensors. ICARUS can be powered by: - Internal lithium battery (3.6V) - External power (8Vdc) ICARUS is always provided with an internal battery satisfying ATEX requirement. The internal battery guarantees a life autonomy of 5 years at normal user conditions. In presence of the external power (compulsory to read HF incoming pulses or to activate the RS 485 serial port) the battery operates as backup power. Attention: external power is supplied by a specific model of power supply that is ATEX certified. It may only be used a battery, or a certified power supply, provided by Fimigas. 3. INSTALLATION SITE ICARUS is generally installed in Zone 1 hazardous area next to the gas pipeline. It can be connected to a modem to remotely transfer recorded gas data. The modem shall always be installed in safe area and connected to ICARUS by an intrinsically safe barrier. The schemes reported below show the typical installation of the device. ICARUS enclosure is provided with 4 fixing threaded holes positioned on the back corners of the device. The internal diameter of the holes is 4 mm. By these holes ICARUS can be both wallfixed and plate-fixed.

4

5 4. DATA READING 9. REFERENCE DIRECTIVES AND ICARUS has ample memory space for data STANDARDS storage. All the values in storage can be read in two Directives different methods: By remote reading of the device via external GSM/GPRS. By local connection to a PC, via optical or RS232/485 serial port. ICARUS meets all the requirements of the UNI 9167 Standard and is already equipped with the CTE communication protocol (upgradeable with future updates), according to UNI TS 11291: ENVIRONMENTAL CONDITIONS - Ambient Temperature: -25 C 55 C - Storage Temperature: -40 C 80 C - Relative Humidity: 0% 100% 6. MID CERTIFICATE - European Directive 2004/22/EC related to measurement instruments (MID), MI European Directive 1994/9/EC related to equipment and protective systems intended to be used in potentially explosive atmospheres (ATEX). - European Directive 2006/95/EC related to low voltage devices; - European Directive 2004/108/EC related to electromagnetic compatibility (EMC); - European Directive 2002/95/EC related to the use of hazardous substances in electrical and electronic equipment (RoHs); - European Directive 2002/96/EC related to collection and recycling of electrical and electronic equipment (WEE). ICARUS received by International Institute of Metrology the Certificate of Approval in accordance with Directive MID (2004/22/CE): MID Certificate: CH-MI ATEX CERTIFICATE ICARUS is an intrinsically safe device and it has two ATEX markings: ATEX Certificate: TUV 11 ATEX X o Ex II 1G Ex ia IIC T4 Ga o Ex II (1)G [Ex ia] IIC 8. DIMENSIONS AND WEIGHT IP 66 plastic case. Dimensions: 210 x 150 x 95 mm Weight: 1,5 Kg. Standards - Italian Standard UNI related to the design, manufacturing and test of natural gas measurements systems; - European Standard ISO /A1, Gas meters Conversion instruments Part 1: Conversion of volume, related to the technical specifics of type 2 volume gas conversion devices. (this is the harmonized Norm of the cited MID Directive); - EN-IEC , Explosive atmospheres Part 0: General requirements, EN-IEC , Explosive atmospheres Part 11: Equipment Protection by Intrinsic Safety, 2007.

6 - IEC : Explosive atmospheres Part 14: Electrical installations design, selection and erection - IEC : Explosive atmospheres Part 17: Inspection & Maintenance Of Installations In Hazardous Areas - EN-IEC , Explosive atmospheres Part 28: Protection of Equipment and transmission Systems using Optical radiation, EN-IEC , Explosive atmospheres Part 26: Equipment with Equipment Protection Level (EPL) GA, EN-IEC , Electricity metering Data exchange for meter reading, tariff and load control Part 21: Direct local data exchange, European Standard ISO /2/3 related to the calculation of gas compressibility factor (Z factor); - AGANX19 Standard related to the calculation of Z gas compressibility factor; - European Standard ISO 6976 related to the calculation of gas density; - International Standard IEC 60529, Degrees of Protection Provided by Enclosures (IP code), 2001.