Summary of Research Project Results under JSPS FY2001
"Research for the Future Program"



1.Research Institution Tokyo Institute of Technology
 
2.Research Area Physical and Engineering Sciences
 
3.Research Field High Efficient Use of Energy and Reduction of its Environmental Impact
 
4.Term of Project FY 1997 〜 FY 2001
 
5.Project Number 97P01003
 
6.Title of Project Fundamental Research on Thermal Energy Storage to Preserve Environment

7.Project Leader
Name Institution,Department Title of Position
Akio, Saito Tokyo Institute of Technology ,Graduate School of Science and Engineering Professor

8.Core Members

Names Institution,Department Title of Position
Masashi, Okada Aoyama Gakuin University, College of Science and Engineering Professor
Isao, Satoh Tokyo Institute of Technology, Graduate School of Science and Engineering Professor
Seiji, Okawa Tokyo Institute of Technology, Graduate School of Science and Engineering Associate Professor

9.Summary of Research Results

The object of this project is to investigate physical phenomena and theories relating to solid-liquid phase change, which form the bases of the dynamic-type ice-making CTES.
(1) Two methods to control the initiation of freezing of supercooled water were examined. In the first method, electrical current was used as the trigger of nucleation and very small element was developed to freeze the water instantaneously. In the second method, a simple instrument was developed which utilize mechanical shock as the trigger. By the method, supercooled water, the temperature of which is higher than -0.2℃, freezes instantaneously. (2) Two dynamic methods were developed, where ice crystals formed in ethylene glycol solution were removed automatically from the cooling surface. In the first method, the ice crystals are removed by buoyancy force acting on the ice. In the second method, the ice crystals are removed by applying horizontal vibration to a vertical cooling plate. In both methods, the cooling surface temperature can be set higher than a representative static method to produce the same amount of ice in a given space. (3) A system to utilize LNG cold waste was proposed. The cold trap is cooled by the LNG cold waste, and water vapor is removed through a pipe line from the evaporator which is located apart from the cold waste. By supplying water shower into the evaporator, ice particles are produced continuously at the triple point. Fundamental researches were performed to evaluate and to improve the method. (4) Methods to produce suspension of fine ice particles from oil-water emulsion were developed. High IPF (ice packing factor) was achieved in a method to produce ice particles by stirring in a vessel. As an alternative method, slurry ice is produced continuously through a pipe. In this method, the cooling surface temperature can also be set higher than a representative static method to produce the same amount of ice in a given space.

10.Key Words

(1)Thermal energy storage、(2)Phase change、(3)Dynamic type
(4)Ice、(5)Trigger、(6)Nucleation
(7)Cold waste、(8)Suspension、(9)Emulsion


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