The Development of The Prototype of A Vaccum Evaporation Type Ice Storage System

• Main Authors: Chia-Ming Tsai, 蔡佳明
• Other Authors: Ming-Tsung Sun
• Format: Others
• Language: zh-TW
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/44614085246801319553

碩士 === 長庚大學 === 機械工程研究所 === 89 === Compared to conventional ice-storage system, a vacuum evaporation type ice storage system (VETISS in short) can improve the energy efficiency of ice making process [1]. However, the VETISS also causes many technical problems concerning actual system manufacturing. This study is mainly involved in solving the problems and develops the prototype of a VETISS. This study is divided into two parts: 1. Design and making of optimized vacuum ice storage tank; 2. Design and making of the required refrigeration system. For the first part we use the FEM[2] based software NASTRAN to analyze the stress of vacuum tanks. Under the limit of used material, we design and make the tank optimized in its weight and manufacturing process. The accessories of the tank, such as water spray circulation system, icing float plate, ice-melting heat exchanger, ice quantity measurement device, are also designed in detail and realized. The goal of the second part is to design a high COP refrigeration system by making use of adjustable expansion valve and water-cooled condenser. The evaporator temperature is adjusted as high as possible such that the advantage of VETISS is fully utilized. To avoid the evaporator efficiency drop due to the increase of frost thickness, the refrigeration system is designed to reverse the cycle into heat pump cycle so that the frost on the evaporator can be removed without extra devices and becomes part of the ice to be made. This gives the best overall energy efficiency.