Design of Refrigerated Railcar for Addis Ababa – Djibouti Railway
| dc.contributor.advisor | Demiss, Alemu (PhD) | |
| dc.contributor.author | Mekonnen, Seid | |
| dc.date.accessioned | 2022-03-16T07:17:23Z | |
| dc.date.accessioned | 2023-11-04T15:17:38Z | |
| dc.date.available | 2022-03-16T07:17:23Z | |
| dc.date.available | 2023-11-04T15:17:38Z | |
| dc.date.issued | 2015-05 | |
| dc.description.abstract | Refrigerated railroad cars, known as reefers, are railroad rolling stock designed to carry perishable freight at specific temperatures. They are insulated boxcars that keep the cargo at a regulated temperature. As soon as railway bulk freight transportation has emerged and railroad cars had the capability to keep a load cold, the potential growth of the meat, vegetables, fruits and brewery industries became nearly unlimited. In this thesis, a current technology and achievement of a cold-room system on transportation system especially in a railroad car was investigated. A refrigerated railroad car with electric powered integrated R134A vapor compression refrigeration system needs to be designed for local manufacturing. The refrigerated railroad car with internal dimensions (17.72 * 2.66 * 2.52) has to be able to preserve and transport a maximum charge of 60000kg of chilled/frozen meat or 42000 kg of chilled vegetables in 24 hours (1 day) to the next mode of transportation, sea transport to Middle East Market. The meat to be frozen and transported enters the refrigerated rail car already frozen to a temperature of about -10°C. Also the meat and vegetables to be chilled and transported enters the car at a temperature of about 2°C and 3°C respectively. The frozen meat leaves the refrigerated railcar and transferred to the refrigerated ship or reefer container at -18°C. A pre-fabricated outer facing with an injected polyurethane is used as an insulation system for the car envelop design and the thermal heat resistance of walls, ceiling and floor is calculated with standard wall thickness. In this design of car envelop the refrigerating space and air circulation is determined for obtaining the optimum air velocity inside the refrigerated railcar. In these design work we use condensing temperature 48°C. Average summertime temperature of AYSHA is 38°C, so there is an average margin of 10°C. For our design purpose we will assume an ambient temperature of 40°C. With these parameters we made cooling load calculations analytically and using computer program and the total cooling load is found to be approximately 19 kW. We use this amount refrigeration capacity for the design process like system component selection and sizing. And finally using the refrigerated railcar envelope and selected refrigerating equipment the most appropriate system configuration has been made. | en_US |
| dc.identifier.uri | http://etd.aau.edu.et/handle/123456789/30619 | |
| dc.language.iso | en_US | en_US |
| dc.publisher | Addis Ababa University | en_US |
| dc.subject | Thermodynamic cycles | en_US |
| dc.subject | heat transfer | en_US |
| dc.subject | transport refrigeration | en_US |
| dc.title | Design of Refrigerated Railcar for Addis Ababa – Djibouti Railway | en_US |
| dc.type | Thesis | en_US |