Development and Evaluation of an Actively Heated and Ventilated Poultry Transport Vehicle
The harsh winter conditions on the Canadian prairies impose special challenges in providing acceptable environmental conditions for broiler chickens during transportation. A research program was developed aiming to improve the transport conditions for broilers. As part of the research program, a research project was developed to design and construct an experimental trailer equipped with active ventilation and heating, to characterize the performance of the experimental trailer in field tests under Canadian Prairie winter conditions, to develop, calibrate and validate CFD models used for simulating the environmental conditions found inside the experimental trailer, and to utilize one of the CFD models to predict the performance of the experimental trailer when subjected to different operational conditions. This dissertation consists of six chapters. The first introductory chapter reviews economical, logistical and legislative aspects surrounding the poultry transport industry. This chapter also includes a discussion of important parameters for the design of an experimental transport system, a review of fundamental concepts of the Computational Fluid Dynamics (CFD) modeling method, and why CFD was chosen as a tool to complement the experimental work in this project. The second chapter reviews the designs of commercial poultry transport equipment and how they inspired the design of an actively heated and ventilated experimental vehicle. The setup of the experimental trailer was also discussed in detail. The third chapter reviews the experimental protocol used to evaluate the performance of the experimental trailer. The performance of this experimental trailer was evaluated in a series of field tests conducted under commercial loading operations, in winter conditions on the Canadian Prairies. It was found that the average load temperature varied from 7.1 to 15.6°C in the nine sts of data. The system was able to maintain an environment above 1°C. As for the humidity level inside the trailer, the majority of sensors had representative relative humidity (RH*) values between 10 and 40%, with the rest having RH* values below saturation. The fourth chapter reviews the development, calibration and validation of the 3-D CFD models developed to simulate the environmental conditions inside the experimental trailer. A total of three CFD models were developed to simulate the three different ventilation regimes encountered in field tests. Sensitivity studies revealed that inlet velocities, heat and moisture production had a great impact on the results obtained from the CFD models. The levels of porosity investigated did not play a significant role. The standard error of estimate was selected as a statistical measure to evaluate the accuracy of the CFD models against experimental data. For temperature data, its standard error of estimate varied from 3.2 to 7.3°C. For humidity ratio, its standard error of estimate varied from 1.7 to 5.0 g of water vapour per kg of dry air. The CFD models were able to recreate the temperature trends as observed from experimental data. It was concluded that these CFD models have adequate accuracy to be used as a design tool for comparative studies. The fifth chapter investigates the use of the 1-fan CFD model to study several scenarios. Three cases were investigated, based on conditions which may be encountered by the poultry transport industry. The first case examined the effects of vehicle travel speed and ambient temperature. The second case looked at the effects of bird size, loading density and ambient temperature. The last case studied the effects of side tarp insulation and ambient temperature. For the range of values examined, results from the simulations concluded that ambient temperature, bird sizes, loading density and side tarp insulation value were important factors to consider in the design of an actively ventilated poultry transport vehicle. The last chapter of this dissertation summarizes the main findings in this research project, discussed future work and presented final conclusions. Overall, this research project answered two key questions in the poultry transport research program. Firstly, the experimental work proved that the concept of active ventilation and heating is a promising option to improve the transport conditions for broiler chickens during cold ambient conditions. Secondly, the CFD work demonstrated that CFD modeling is a valuable tool for designing the next generation of actively ventilated poultry transport vehicle.
broiler, poultry, transport, CFD, ventilation, heating
Doctor of Philosophy (Ph.D.)
Chemical and Biological Engineering
Agricultural and Bioresource Engineering