Optimum Design Methods of Pressure Cooling System for Fruits and Vegetables

Research Project

Project/Area Number	62560248
Research Category	Grant-in-Aid for General Scientific Research (C)
Allocation Type	Single-year Grants
Research Field	農業機械
Research Institution	Kagoshima University
Principal Investigator	TANAKA Shun'ichiro Faculty of Agriculture, Assistant Professor, 農学部, 助教授 (80041664)
Project Period (FY)	1987 – 1988
Project Status	Completed (Fiscal Year 1988)
Budget Amount *help	¥2,100,000 (Direct Cost: ¥2,100,000) Fiscal Year 1988: ¥700,000 (Direct Cost: ¥700,000) Fiscal Year 1987: ¥1,400,000 (Direct Cost: ¥1,400,000)
Keywords	Pressure cooling system / Precooling / Eruits and vegetables / Unit cooling energy consumption / Optimum superticial velocity / 最適熱伝達係数 / 予冷青果物
Research Abstract	In order to establish the optimum design methods of pressure cooling system for fruits and vegetables, first, cooling time, superficial velocity and energy consumption for some fruits and vegetables were measured by experiment, secondly, heat transfer coefficients for cooling packed beds of fruits and vegetables were calculated by finite element method. Results obtained were as follows: (1) The author defined that the energy required to cool one centigrade per kilogram with opparatus load was a unit cooling energy consumption(U.C.E.C). (2)The cooling of agricultural products by superficial velocity correspond to a minimum U.C.E.C. meant that the ratio of refrigerator energy to total U.C.E.C. had a maximum and it of axial flow fan had a minimum. (3) The superficial velocities at that time were 0.2-0.4m/s for any packed beds of agricultural products, and U.C.E.C. of agricultural products were 1.6-3.3x10 kw. hr/kg C. these values were smaller than that of forced air cooling. (4) The optimum heat transfer coefficient were 20 for packed bed of Unshu Mandarin and 25 kcal/m^2 hr C for taro, respectively.