Post on 26-Dec-2015
Energy in Tropical Climates
a practical approach
CEE-Engineering, Korenstraat 10, 3010 Kessel-Lo, Leuven, Belgium
Overview1. Basic elements
• Energy• Types and sources• Generation – conversion – transport – storage – consommation
2. Tropical-specific situations• Micro-climate• Independency• People
3. The Field Hospital• Design• Maintenance• Tropical Toolkit
4. Questions
CEE-Engineering, Korenstraat 10, 3010 Kessel-Lo, Leuven, Belgium
Basic Elements1. Energy
• Greek: ενεργός => “active, working”• Energy = the capacity to do work
• Mechanical interpretation
CEE-Engineering, Korenstraat 10, 3010 Kessel-Lo, Leuven, Belgium
Energy[Joule]
Work[Joule]
Power[Watt]
Basic Elements1. Energy
• Greek: ενεργός => “active, working”• Energy = the capacity to do work
• Electrical interpretation
CEE-Engineering, Korenstraat 10, 3010 Kessel-Lo, Leuven, Belgium
Energy[Joule]
Work[Joule]
Power[Watt]
Basic Elements2. Types and sources of Energy
• Mechanical energy– Movement off mass: waterstream, rotating axis,…– Loaded spring– Compressed air
• Thermal energy– Heat or cold– Boiler– Heat pump– Refridgerator
• Electrical energy– Movement of elektrons (ampère)– Battery/generator/dynamo/…
• Chemical energy– Endothermal/exothermal reactions– Reduction/oxidation reactions– Battery
• Nuclear EnergyCEE-Engineering, Korenstraat 10, 3010 Kessel-Lo, Leuven, Belgium
Energy[Joule]
Power[Watt]
Work[Joule]
Basic Elements3. Generation – conversion – transport – storage -
consommation
• Consommation - type– Heat / cold : refridgeration, air-conditioning– Electricity: laptops, microscopes, lights,…– …
• Generation - type– Mechanical: rotating axis (wind, water-stream)– Fysico-Chemical: Acid solution, Solar radiation– …
• Conversion Performance– From one type to another– Within the same type (for example high voltage => low voltage)– Always loss of energy => minimize amount of conversions
CEE-Engineering, Korenstraat 10, 3010 Kessel-Lo, Leuven, Belgium
Basic Elements3. Generation – conversion – transport – storage -
consommation
• Transport of energy– Heat / cold : piping-systems– Electricity: wires and cables– …
• Storage of energy– Difficult– Not possible without losses– E.g.: battery systems (long term storage), fly wheel (short term storage)
CEE-Engineering, Korenstraat 10, 3010 Kessel-Lo, Leuven, Belgium
Tropical-specific situations1. Micro-Climate
• Extreme temperatures: up to 40 °C is normal
» Cooling of computers/engines/generators more difficult» Cold chain for medicines is must
• Extreme humidity: up to 100% relative humidity
» Heavy corrosion problems» Short circuits because of condensate
• Extreme Lightening
» Tension peakes damages elektrical equipment
• Extreme Rain
» Damages ill-protected electrical circuits
CEE-Engineering, Korenstraat 10, 3010 Kessel-Lo, Leuven, Belgium
Tropical-specific situations2. lndependancy
– No or old Local area energy-systems
– Very insulated areas => transport-cost
– Long-distance transport => spare-parts!
3. Local People– Very pore
– Understanding attitude is must
basic toolkit, spare-parts and back-up systems necessary
CEE-Engineering, Korenstraat 10, 3010 Kessel-Lo, Leuven, Belgium
The Field Hospital
CEE-Engineering, Korenstraat 10, 3010 Kessel-Lo, Leuven, Belgium
The Field Hospital1. Design
– Consommation detail– Generation possibilities– Back up systems– Protection of the complete system– Human protection
2. Maintenance
– Small maintenance– Big maintenance– Spare parts
CEE-Engineering, Korenstraat 10, 3010 Kessel-Lo, Leuven, Belgium
The Field Hospital1. Design: Consommation detail
• Office: 2 normal rooms
– Light bulbs: 4 x 50 W = 200 W – TL-lights (give brighter light): 4 x 20 W = 80 W– Computers: 2 x 400 W = 800 W– Laptops: 3 x 75 W = 225 W– Air-conditioning: 1 x 1.8 kW = 1.8 kW– Ventilators: 2 x 60 W = 120 W– Printers: 1 x 100 Watt
=> TOTAL = 3.3 kW
CEE-Engineering, Korenstraat 10, 3010 Kessel-Lo, Leuven, Belgium
The Field Hospital1. Design: Consommation detail
• Lab (1 room)– Light bulbs: 2 x 50 W = 100 W – TL-lights (give brighter light): 2 x 20 W = 40 W– Computers: 1 x 400 W = 400 W– Air-conditioning: 1 x 1.8 kW = 1.8 kW– Microscopes: 2 x 50 W = 100 W– Sterilisator / autoclaves: 2 x 1.4 kW– Refridgerator (6°C): 1 x 200W– Fridge (- 20 °C): 1 x 350 W
=> TOTAL = 5.8 kW
CEE-Engineering, Korenstraat 10, 3010 Kessel-Lo, Leuven, Belgium
The Field Hospital1. Design: Consommation detail
• Surgery (1 room)– Light bulbs: 2 x 50 W = 100 W – TL-lights (give brighter light): 2 x 20 W = 40 W– Operating Lamp: 2 x 80 W = 160 W– Air-conditioning: 2 x 1.8 kW = 3.6 kW– Aspirator/Oxygen-equipment: 300W
=> TOTAL = 4.2 kW
CEE-Engineering, Korenstraat 10, 3010 Kessel-Lo, Leuven, Belgium
The Field Hospital1. Design: Consommation detail - Overview
CEE-Engineering, Korenstraat 10, 3010 Kessel-Lo, Leuven, Belgium
place item consommation urgency
[W] [W]Office light 280 0 computers 800 0 laptops 225 0 Air-conditioning 1800 0 Ventilators 120 0
Printers 100 0Lab light 140 140 computers 400 0 Air-conditioning 1800 0 microscopes 100 0 sterilisators/autoclaves 1400 700 refridgerator 200
fridge 350 Surgery light 140 140 operation lamp 160 80 Air-conditioning 3600 1800
aspirator/O²-equipment 300 300
SUM 11915 3160
The Field Hospital1. Design: Generation Possibilities
• Demands = Electrical energy for equipment– Tension = 230 V– 2 phazes– Alternating current (AC)– 50 Hz– Power determined according to previous information
CEE-Engineering, Korenstraat 10, 3010 Kessel-Lo, Leuven, Belgium
The Field Hospital1. Design: Generation Possibilities
• Solar Systems - characteristics– The panel: photovoltaic cells (silicium semi-conductant)– Solar energy is converted into electrical energy– The power-generation: Direct-current (DC)– Tension generation = 12 V– Sun-dependent– Orientation-dependent– Expensive– Generation: 125 Wp / m²
CEE-Engineering, Korenstraat 10, 3010 Kessel-Lo, Leuven, Belgium
The Field Hospital1. Design: Generation Possibilities
• Solar Systems
12V - Direct current Invertor (12V/230V) Consommation 125 W >125 W <125 W
REMINDER: EVERY Equipment in the conversion chain, must be able to transport the power.
PROBLEM: Sun does not shine when we would like to, even in tropical climates
CEE-Engineering, Korenstraat 10, 3010 Kessel-Lo, Leuven, Belgium
The Field Hospital1. Design: Generation Possibilities
• Solar Systems with integrated battery-system
12V - Direct current Charger/Invertor (12V/230V) Consommation 125 W >125 W <125 W
Battery: 12 V, 120 Ah
CEE-Engineering, Korenstraat 10, 3010 Kessel-Lo, Leuven, Belgium
The Field Hospital1. Design: Generation Possibilities
• Generator systems
– Motor/EngineFrom chemical energy (diesel) into mechanical energy
– Rotating axis
– Generator/Alternator
CEE-Engineering, Korenstraat 10, 3010 Kessel-Lo, Leuven, Belgium
The Field Hospital1. Design: Generation Possibilities
• Generator systems: Types
– Mono-phaze (2 cables output)
CEE-Engineering, Korenstraat 10, 3010 Kessel-Lo, Leuven, Belgium
The Field Hospital1. Design: Generation Possibilities
• Generator systems: Types
– Tri-phaze (4 cables output)
CEE-Engineering, Korenstraat 10, 3010 Kessel-Lo, Leuven, Belgium
The Field Hospital1. Design: Generation Possibilities
• Generator systems: Types
– Monophaze Tri-phaze
=> Tri-phaze better for tropical climates because of lower rotationspeed of the axis. (lower wear and tear)
CEE-Engineering, Korenstraat 10, 3010 Kessel-Lo, Leuven, Belgium
Poles RPM at 50Hz RPM at 60Hz
2 3000 3600
4 1500 1800
The Field Hospital1. Design: Generation Possibilities
• Generator systems: characteristics
– Power-output in kVA e.g. 15 kVA
– Performance in cosinus-phi e.g. 0.8
– Mono-phaze or 3: Power calculation is different!
CEE-Engineering, Korenstraat 10, 3010 Kessel-Lo, Leuven, Belgium
The Field Hospital1. Design: Generation Possibilities: CONCLUSIONS
• Combination of solar and generator systems
– Smaller power demand (lights, portable pc) with solar panels
=> +- 6 m² is necessary with 3 batteries of 120 Ah, 12V
– Higher powerdemands (cooling, sterilisation) with generator
=> Rest with 3-phaze generator of 10 kVA (3.5 L/h diesel)
– Emergency-power (in case of surgery)
=> 3-phaze generator of 5 kVA (2.5L/h diesel)CEE-Engineering, Korenstraat 10, 3010 Kessel-Lo, Leuven, Belgium
The Field Hospital1. Design: Generation Possibilities: CONCLUSIONS
• Extras: depending on local opportunities
– Micro-hydro central (5 up to 100 kW)
CEE-Engineering, Korenstraat 10, 3010 Kessel-Lo, Leuven, Belgium
The Field Hospital1. Design: Generation Possibilities: CONCLUSIONS
• Extras: depending on local opportunities
– Vertical-axis wind mill (300W up to 20 kW)=> minimum wind-speed of 8 km/h necessary!
CEE-Engineering, Korenstraat 10, 3010 Kessel-Lo, Leuven, Belgium
The Field Hospital1. Design: Back-up system
• UPS
– Uninterruptible Power Supply
– Based on batteries (loaded) and regulating electronics with detection system
– Characterized by maximal power (kW) and maximum stand-alone run time (usually 5 up to 10 minutes)
CEE-Engineering, Korenstraat 10, 3010 Kessel-Lo, Leuven, Belgium
The Field Hospital1. Design: Back-up system
• UPS
– Most reliable type: double-conversion method
Protects at same time for powerdips, tensionspikes, frequency-modulation …
Double energy-conversion = losses (up to 10 %)CEE-Engineering, Korenstraat 10, 3010 Kessel-Lo, Leuven, Belgium
The Field Hospital1. Design: Back-up system
• UPS
– Alternative types: off-line UPS
Start time 2 ms after feeding-disturbance Only reliable when current falls out
CEE-Engineering, Korenstraat 10, 3010 Kessel-Lo, Leuven, Belgium
The Field Hospital1. Design: Back-up system
• UPS
– Alternative types: line-interactive UPS
Incoming power is filtered Not as much certainty as double conversion UPS
CEE-Engineering, Korenstraat 10, 3010 Kessel-Lo, Leuven, Belgium
The Field Hospital1. Design: Protection of equipment and humans
• Tension-disturbance
– Lightening– Failure of alternator– After start of heavy electric equipment
UPS double conversion type AVR-technologie (Automatic Voltage Regulation)
DUST-FREECEE-Engineering, Korenstraat 10, 3010 Kessel-Lo, Leuven, Belgium
The Field Hospital1. Design: Protection of equipment and humans
• Current-protection
– Lightening– Failure of alternator– During start of heavy electric equipment
On every line (phaze and zero-line) Don’t take it out! TT 250/62mA TT250/1.6A
DUST-FREECEE-Engineering, Korenstraat 10, 3010 Kessel-Lo, Leuven, Belgium
The Field Hospital1. Design: Protection of equipment and humans
• Earthening of equipment
– To protect the steel casing/chassis to get loaded because of elektromagnetic coupling or leakage current
– Protects against possible elektroshocks. VERY IMPORTANT FOR WEAK PATIENTS
CEE-Engineering, Korenstraat 10, 3010 Kessel-Lo, Leuven, Belgium
The Field Hospital1. Design: Protection of equipment and humans
• Earthening of equipment
– Connection of casing with the earth
– Wires have to be big enough, otherwise no protection
CEE-Engineering, Korenstraat 10, 3010 Kessel-Lo, Leuven, Belgium
The Field Hospital1. Design: Protection of equipment and humans
• Differential current-switch
– Human elektro-shock– Loading of other tool with tension (static)
=> On every phaze !CEE-Engineering, Korenstraat 10, 3010 Kessel-Lo, Leuven, Belgium
The Field Hospital1. Design: Protection of equipment and humans
• Lightening – Faraday’s cage
– Static tension in clouths above earth– Break through of the current in the atmosphere into earth– Looks for high peaks
CEE-Engineering, Korenstraat 10, 3010 Kessel-Lo, Leuven, Belgium
The Field Hospital2. Maintenance: Strugle against DUST, HEAT and SUN
• Electric devices/networks
– Keep the performance of the equipment high– Keep clean from dust– Check protection switches by means of multimeter– Every 6 months, complete electric circuit has to be checked (connections
screwed, insulation of wiring, ..)– Keep the consommation in balance with the production– Check on regular basis battery-quality– Check the UPS-systems
CEE-Engineering, Korenstraat 10, 3010 Kessel-Lo, Leuven, Belgium
The Field Hospital2. Maintenance: Strugle against DUST, HEAT and SUN
• Mechanics
– Keep clean (cooling fans of motors, electric connections)– Exhaust gases of motors must be able to quit the place– Steel moving parts: clean and grease– Rubber bands: check for deterioration and replace in time– Transparancy-Test the fuel in a glass before consuming it
CEE-Engineering, Korenstraat 10, 3010 Kessel-Lo, Leuven, Belgium
The Field Hospital3. Tropical toolkit
– Multimeter
– Basic tools
CEE-Engineering, Korenstraat 10, 3010 Kessel-Lo, Leuven, Belgium
The Field Hospital3. Tropical toolkit
– Spare-protection
– Spare wiring/contacts
CEE-Engineering, Korenstraat 10, 3010 Kessel-Lo, Leuven, Belgium
The Field Hospital3. Tropical toolkit
– Oil/grease
– Rubber
CEE-Engineering, Korenstraat 10, 3010 Kessel-Lo, Leuven, Belgium
Questions ?
CEE-Engineering, Korenstraat 10, 3010 Kessel-Lo, Leuven, Belgium