Cryogenic design and test results of 30-m flexible hybrid energy transfer line with liquid hydrogen and superconducting MgB2 cable

Mixed refrigerant cycle with neon, hydrogen, and helium for cooling sc power transmission lines

“…Such a concept is called a hybrid transfer line. The concept of superconducting cables based on high temperature superconductors (HTS) cooled by hydrogen [4] or nitrogen ( [12] and [13]) has been already proven successfully in demonstrators and even industrial applications [11]. But the longest cable project so far is only 1 km long, which is far less than the proposed length of several hundred kilometers.…”

“…There is also a line in the phase diagram, where two liquid phases aswell as a gas phase form. 4 Figure 2. possible cycles, left: single separator, right: addition of a second separator to use the heat of evaporation of hydrogen The above calculations can be applied to this phase equilibrium data.…”

“…In recent years, several publications suggested the integration of superconducting MgB 2 power transmission lines cooled by liquid hydrogen (LH 2 ) or gaseous helium (GHe) at 20 K into the grid [1][2][3][4][6][7][8]. The simultaneous transfer of electrical and chemical energy seems advantageous if LH 2 is demanded at one end of the transmission line, too.…”

“…Regardless of the cooling machine's working principle, such recooling plants need to operate very cost efficient and at high availability levels to provide a reliable power transmission path. Actual sc cable demonstrators are utilizing the concepts of lost boiling of LN 2 (see [11]) or cryocoolers (see [4,12,13]) to compensate the heat load. These have proven to be sufficient for the demonstrators.…”

Some results of an experimental study of the process of cooling down a model of a hybrid power system for high power transmission

“…Taking into account the latest technical advances and requirements for energy transmission, a new hybrid system for the transmission of large energy flows has been proposed [1][2]. In this system, electricity and liquefied gas (hydrogen or natural gas) are transmitted at the same time.…”