Liquid nitrogen low-temperature system for superconducting current limiter

Abstract

A liquid nitrogen low-temperature system for a superconducting current limiter belongs to the field of low-temperature engineering and technique. The liquid nitrogen low-temperature system comprises a liquid nitrogen container, a liquid nitrogen valve, a liquid nitrogen refuel valve, a safety valve, a valve cap, a test Dewar, a thermal insulation layer, a rupture disk, a deflation valve, a flow meter, a vacuum measurement gauge, a pressure difference sensor, a pressure sensor, a support part, a pumping valve, a vacuum pump, a superconducting current limiter, a control circuit, a temperature sensor and a discharging air pipe. In the invention, the system adopts the liquid nitrogen as the cooling working medium; the superconducting current limiter for the test is placed in the test Dewar; switching between the superconducting state and superconducting loss state of the superconducting current limiter can be realized through the control circuit; and the pressure, pressure difference and temperature measured by the pressure sensor, the pressure difference sensor and the temperature sensor, and the quality flow of the gasified nitrogen in the superconducting loss state measured by the flow meter are inputted into a computer, so as to evaluate the refrigeration wastage of the low-temperature system of the superconducting current limiter, and study the influence of the bubbles exerted on the low-temperature system pressure intensity when superconducting current limiter is abnormal. The low-temperature system has the advantages of simple structure, good economical efficiency, and favorable safety.

Description

technical field [0001] The invention relates to a superconducting current limiter liquid nitrogen cryogenic system, in particular to a superconducting current limiter cryogenic system for evaluating the cooling loss of the superconducting current limiter cryogenic system and studying the influence of bubbles generated when the superconducting current limiter quenches on the pressure of the cryogenic system Liquid nitrogen cryogenic system with flow limiter. It belongs to the field of cryogenic engineering and cryogenic technology. Background technique [0002] Adding a superconducting current limiter to the power grid is a new technology to limit the short-circuit current of the power grid. The basic working principle of the superconducting current limiter is to use the transition between the superconducting state and the normal state (S / N) of the superconductor, which behaves as a superconducting state when the power grid is operating normally. When a short-circuit fault o...

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Problems solved by technology

Although the closed system saves the amount of liquid nitrogen used to a great extent, the cost is high due to the addition of a refrigerator. If it is only used for the performance test of the superconducting current limiter, it does not meet the economic requirements.

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