制冷_外文期刊.docx

Jonrnal of Applied Sciences (8):788-794,2008ISSN 1812Asian Network for Scientific InformationDesigning of Cold Stores and Choosing of System ElementsS.AkdemirAir-Condition and Refrigeration Programme, Vocational School,Namik Kemal University, 59030 Tekirdag, TurkeyAbstract:In this study, calculation of cooling load and choosing of the cooling system elements such as compressor, condenser and evaporator were explained for designing of the cold storage. Transmission heat (q1), infiltration heat (q2), product heat (q3),heat of other sources(q4) and unknown and unexpected heat (q5) which is components of the cooling load were calculated. In addition, amount of the cooling fluid was calculated and choosing of the compressor, the condenser and the evaporator were explained.Key words:Cold storage, cooling load, compressor, condenser, evaporatorINTRODUCTIONCooling can be defined as the decrease of temperature of a substance or medium below temperature of its environment (Anonymous, 2001). Refrigeration is a process of lowering the temperature and maintaining it in a given space for the purpose of chilling foods, preserving certain substances, or providing an atmosphere conductive to bodily comfort. Storing perishable foods, pharmaceuticals, or other items under refrigeration is commonly known as cold storage. Such refrigeration checks both bacterial growth and adverse chemical reactions that occur in the normal atmosphere.The most important factor in cold storage is ambient temperature. As a rule, the temperature in cold storage is higher than 1-2℃, which is the freezing point temperature of stored fruit and vegetable. Stored product must not be freezing in the cold storage (Cemeroglu and Acar, 1986). Ozkol (1999) reported that there is heat transfer in many places of cooling system and that the heat transfer widely takes place during the process. Tashtoush (2000) investigated process of heat and mass transfer during cold storage of fruits and vegetables and deter