Design and development of an evaporative cooling system for tropical fruits and vegetables in transport vehicles | |
| Author | Nattriya Supmoon |
| Call Number | AIT Thesis no.FB-09-07 |
| Subject(s) | Vegetables--Cooling--Tropics Fruit--Cooling--Tropics Tropical fruit Evaporative cooling Tropics |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Food Engineering and Bioprocess Technology, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. no. FB-09-07 |
| Abstract | Temperature management is critical during transportation of tropical fruits and vegetables over long distance. To reduce the initial cost and the high demand of input energy of refrigeration system during transport, a modified evaporative cooling system named Two-stage evaporative cooler includes plate heat exchanger in front of direct evaporative cooler has been designed for transport vehicle. The experiment was conducted to select the best operating conditions for designing of evaporative cooling system. Lab-scale evaporative cooler was constructed to evaluate the effect of operating conditions on the cooling efficiency that take place in Asian Institute of Technology, Thailand with a temperature ranged from 21 to 28°C and average 50-80% relative humidity. The results show that thickness of cooling media and inlet air velocity are two main effects that the cooling efficiency will increase with an increase in thickness of cooling media and a decrease in inlet air velocity due to the increased waterair contact surface and time. These data were used to correlate cooling efficiency based on the energy balance analysis. Two-stage evaporative cooler can reduce dry bulb temperature by 10°C and the cooling efficiency varies over a range of 104-107% at the different speed of car range from 40 to 80 km/hr. Furthermore, the temperature and relative humidity in the storage room are maintained almost constant at about 20°C temperature and 97% relative humidity with speed of car variation compared to Single-stage evaporative cooler. Finally, the effect of three cooling methods, including an ambient condition, Two-stage evaporative cooling condition, and refrigerated condition, on short term storage of tomatoes was studied. The quality criteria monitored were weight loss, firmness and color (a-value). Quality evaluation was done after harvest 6 hours supposed for transportation period and daily basis of 7 days supposed for storage period. Results show that there was a significant different in the quality characteristics of tomatoes in different cooling method on transportation period and storage period on time of the development. The lowest weight loss occurred in the evaporative cooling condition by 1.83% while the lowest color (a-value) at -1.74 and the highest firmness at 25 N occurred in the refrigerated condition. Due in part to the lower primary investment, the evaporative cooling system may be the alternative way in selecting the cooling system for transport tropical fruits and vegetables. |
| Year | 2009 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. no. FB-09-07 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Food Engineering and Bioprocess Technology (FB) |
| Chairperson(s) | Athapol Noomhorm; |
| Examination Committee(s) | Rakshit, Sudip Kumar;Salokhe, Vilas M.; |
| Scholarship Donor(s) | Thailand HM (Queen); |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2009 |