Studying And Designing Of The Refrigeration System In The Hundred-meter Level Cold Dielectric HTS Cable

Since the discovery of high temperature superconductor (HTS), HTS power applications, the possibility has been strongly attracted the industrialized countries. It seems from the current, HTS power cable application of rapid development, most likely the first widely used in the power system. Compared to conventional cables, high temperature superconducting cable with a small size, light weight, low loss and transmission capacity, etc., using high-temperature superconducting power transmission cables to solve power density urban construction land, the best tension transmission program, have broad market prospects. HTS high temperature superconducting cable is one of the important applications of technology, it integrates superconducting materials, cables, low-temperature refrigeration, electrical engineering technology and other subjects.This paper describes the 30-meter HTS cable system experiment content, design and major equipment on the refrigeration system, the energy of the cryogenic system and the experimental results are analyzed. Compare the pros and cons of various low-temperature refrigeration system, by comparing the operation and the various domestic and international research, and study the various domestic and international large-scale progress in helium refrigeration system, the choice of the helium refrigeration system to achieve the cooling capacity of the project. Meters for the entire class HTS cable cooling system programs choose to make a preliminary established.In this paper, pairs of meter-class high-temperature superconducting cable parameters of the thermodynamic state point analysis and optimization of the cooling stage refrigeration cycle and heat exchanger to heat balance analysis, and gives the design parameters of each state point, and shows the performance of helium refrigeration cycle and its irreversible loss. All of these refrigeration cycle analysis is fundamental to the design refrigerator, refrigerator in the main equipment, such as heat exchangers, compressors, expanders, valves, vacuum pumps, buffer tanks such as the design, selection of parameters from Thermodynamic analysis of optimal results.This paper focuses on the critical helium refrigeration system equipment, such as screw compressors, plate-fin heat exchanger, turbo expander, cryogenic liquid pumps, vacuum pumps, control valves, such as buffer tank selection and design were discussed. Given the characteristics of the screw compressor, performance evaluation, the process of screw compressors and screw compressors organization design and selection parameters. Discusses the low-temperature plate-fin heat exchanger design, including the selection of fins, channel allocation, the calculation of heat transfer coefficient and pressure drop, heat exchanger area calculation. Also discusses the impact of heat exchanger efficiency of several factors. This chapter also gives the machine and cryogenic liquid expansion turbine pumps and vacuum pump design parameters and design results. Finally, the role that the buffer tank and work.This thesis is based on the design of the refrigeration system in the hundred-meter level CD HTS cable as the main content,gives the helium refrigeration system design and the caculation results, hoping for do a certain contribution for our studies of the refrigeration system in the hundred-meter level CD HTS cable.