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© ABB | Slide 1 Automation & Instrumentation in the Irrigation Sector James MacLellan – ABB Limited Irrigation show, April 2014 January 2014
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© ABB | Slide 2 Presentation topics covered Accurate metering of water use and adherence to legislative requirements Optimising water usage Control of water quality standards Mitigation of electrical issues for the wider community Managing energy efficiency Month DD, YYYY
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© ABB | Slide 3 Accurate metering of water use Month DD, YYYY
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© ABB | Slide 4 What is required? Consent holders need to provide data regarding water takes. Flow data needs to be within 5% of a known standard value* *ABB units are OIML R49 Type P. Month DD, YYYY
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© ABB | Slide 5 So which device and why? Mechanical Meters Paddle wheel / Turbine / Gear. Inexpensive & simple. Accuracy limitations. Moving parts. Coriolis Flow Meter Uses principle of inertia for moving mass. Extremely accurate, minimal install requirements. Limitation on bore size. Expensive Month DD, YYYY
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© ABB | Slide 6 So which device and why? Differential Pressure Bernoulli’s Principle (> speed = < pressure). Requires a constriction. Not super ideal for irrigation sector. Electromagnetic Magnetic induction. Without mechanical ‘moving’ parts. Any ionic electrically conductive fluid. Month DD, YYYY
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© ABB | Slide 7 Optimising water usage Month DD, YYYY
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© ABB | Slide 8 Efficiency = (H 2 O Transpired / H 2 O Applied) x 100 Need to obtain some detail as to:- 1. How much water has been provided to the crop (applied) 2. How much water is absorbed by the crop (transpired) Need to MEASURE 1. Rainfall. 2. Soil depth. 3. Soil moisture. 4. Pasture response. 5. Irrigation application rate and efficiency. Month DD, YYYY
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© ABB | Slide 9 Factors ‘below the surface’. Month DD, YYYY
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© ABB | Slide 10 Efficiency = (H 2 O Transpired / H 2 O Applied) x 100 Soil temp @ 10cm depth < 10 deg C: Nil growth. Soil temp @ 10cm depth > 10 deg C: Sun / Moisture. --------------------------------------------------------------------------------- So, measure temperature @ 10cm depth. Crop & Food Research: R.J Martin, S.M.Thomas, R.F. Zykowski AgResearch: D.R Stevens Month DD, YYYY
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© ABB | Slide 11 Instruments & technology in use today Month DD, YYYY
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© ABB | Slide 12 Pt100 0.385 ohms per degree C LINEAR Accurate $$$$$$$ Thermistor Similar principle to Pt100 NON LINEAR Not so accurate Cheap! Pt100 & Thermistor (RTD’s) Month DD, YYYY
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© ABB | Slide 13 Possible methods:- Capacitance Resistance Conductivity Temperature Soil moisture content Most common:- Time Domain Transmission Electrical pulse Time / size affected by surrounding media Month DD, YYYY
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© ABB | Slide 14 Conditions constant. Repeatable result. Imagine the wall changes… The speed, time & force of the returning ball will very. Alter one ‘constant’. Results vary Moisture change = change in pulse signal properties Time Domain Transmission Month DD, YYYY
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© ABB | Slide 15 3 rd Law of induction (1832). Left Hand Rule (motors). mV signals generated Electro-magnetic field ‘switches’. mV signal size proportional to flow. The Electro-Magnetic Flow Meter Month DD, YYYY
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© ABB | Slide 16 Control of water quality standards Month DD, YYYY
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© ABB | Slide 17 pH (measure of acidity / alkalinity) Conductivity (measure of ionic concentration) Turbidity (measure of the particulates) Chemical analysis… Month DD, YYYY
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© ABB | Slide 18 pH / Conductivity / Turbidity Month DD, YYYY
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© ABB | Slide 19 Nitrate & Dissolved Oxygen Analysis Leaching Human health issues Death of fish & marine species Affect soil nutrition (< Ca) Reduced by decomposition of organics (>BOD) Affect aquatic species Month DD, YYYY
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© ABB | Slide 20 Mitigation of electrical issues & managing energy efficiency Month DD, YYYY
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© ABB | Slide 21 Instruments: Delicate / Fragile / Fine / Precise Month DD, YYYY
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© ABB | Slide 22 Getting the Water The crowded room Energy required to ‘lift’ or ‘pump’ water. Most efficient use of electrical energy via VSD / VFD. Month DD, YYYY
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© ABB | Slide 23 Extremely efficient devices with regard to power use. ‘Raw’…VSD’s can cause huge power issues across networks and disrupt/distort instrument signals If you install them 100%...The instrumentation guy is happy…Everybody is happy Variable Speed Drives (VSD / VFD) Month DD, YYYY
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© ABB | Slide 24 Sending the signals Miscommunications Month DD, YYYY
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© ABB | Slide 25 Conventional Flow data via pulses. Telecommunication fail. Pulses / units disagree. Punch up. Common issues – Missing data Serial communication Flow data via digital comms Receiver reads instrument value from a register Doesn’t matter if communications are intermittent MODBUS Month DD, YYYY
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© ABB | Slide 26 Energy Efficient Devices Month DD, YYYY
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© ABB | Slide 27 Le Chatelier’s Principle Month DD, YYYY
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© ABB | Slide 28 What we don’t want to see…. Month DD, YYYY
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© ABB | Slide 29 “Before you rip down a fence, think for a moment why it was put there in the first place” Month DD, YYYY
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