Colloque lille2017 sequence7a6-medibate_robin-amand_en
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Transcript of Colloque lille2017 sequence7a6-medibate_robin-amand_en
Thermal modelling of livestock housing for broilers to optimize the choice of equipment
and control parameters.
P. Robin1, G. Amand2, C. Nicolas3, D. Chevalier4, S. Gallot2, E. Pigache4 , A. Keïta5
1INRA, 2ITAVI , 3CRAB , 4CRAPL , 5ANSES - France
Lille - 22 to 24 February 2017Livestock housing: let's build the future 2
Summary
• Why model? example of CO2
• Problem of managing CO2– Variability of concentrations on farm (uncertainty)– Effect of control parameters: minimum flow, temperature setpoint
(farmer settings)– Effect of structural choices: thermal insulation, type of heating
(housing - equipment)– Weather impact (weather)
• Conclusion: implications for management or investment decisions
Why model? example of CO2
Why model? example of CO2
introduction uncertainty farmer settings housing - equipment weather conclusion
uncertainty of observation?
causes of excesses?
remedies?
ppm CO2
Freq
uenc
yof
ex
cess
• Requirement: 3000 ppm CO2 in broilers
Why model? example of CO2
introduction uncertainty farmer settings housing - equipment weather conclusion
• Requirement: 3000 ppm CO2 in broilers • Processes affecting concentration
CO2animals = f(weight,
growth,activity)
heating = f(weather, insulation,
ventilation)bedding
= f(thickness, humidity)
Ventilation= f(animals, weather)
causes of excess
• housingdesign
• farmer settings
• weather
Problem of managing CO2
Variability of concentrations on farm
• Variability increases in cold weather
• Increased variability is due to the difficulty in mixing air between: incoming cold air
(low in CO2) hot air blown by
the gas heater (high in CO2)
ambiant air
introduction uncertainty farmer settings housing - equipment weather conclusion
• ANSES observation, 2015, standard chicken
Effect of the control parameters: simulation of scenarios
• Baseline scenario = – mild weather at start of batch, cold at end of
batch– “traditional” housing insulation– gas heating by direct combustion in the
housing – minimum flow rate as per AFSSA, 1980 – setpoint temperature 19°C at end of batch
introduction uncertainty farmer settings housing - equipment weather conclusion
• Test scenarios = weather effect = 5°C decrease in temperature (symbol ) effect of settings = increased minimum flow (0.5 to 2 m3/h/kg bodyweight) housing effect = insulation; indirect combustion (no CO2 produced in the housing;
line - - - -)
Effect of the control parameters: minimum flow
introduction uncertainty farmer settings housing - equipment weather conclusion
increase in minimum flow
• effect of settings = increased minimum flow (0.5 to 2 m3/h/kg bodyweight) lower concentration of CO2 when min. flow increases
Effect of the control parameters: minimum flow
introduction uncertainty farmer settings housing - equipment weather conclusion
increase in minimum flow
• effect of settings = increased minimum flow (0.5 to 2 m3/h/kg bodyweight) increase in gas consumption; limited impact at start of batch considerable economic and environmental impact at end of batch
Effect of structural choices: thermal insulation; indirect combustion
introduction uncertainty farmer settings housing - equipment weather conclusion
• housing effect = thermal insulation; heating mode low effect of insulation greater effect of indirect combustion
normal insulation reinforced insulation (LEB)
weather effectintroduction uncertainty farmer settings housing - equipment weather conclusion
• weather effect = increase in CO2 content and gas consumption increase in gas consumption; limited impact at start of batch considerable economic and environmental impact at end of batch
When the weather is cold the heat produced by the animals is insufficient to heat the incoming air => heat exchangers needed at end of batch
Conclusion: implications for management or
investment decisions
Conclusion
Possible decisions = short term housing settings: minimum flow at start of batch; setpoint temperature at end
of batch
introduction uncertainty farmer settings housing - equipment weather conclusion
Possible decisions = medium term (depending margin/m² housing, availability) investments in housing/equipment: indirect combustion; biomass (economic
and environmental impact at end of batch); reinforced thermal insulation; heat recovery exchangers
Controls to check settings; planning of farm modernization; development of adapted equipment
Any questions?