A 6-m long liquid nitrogen based cryo transfer line has been designed, developed and tested at IPR. The test objectives include the thermo-hydraulic characteristics of Cryo transfer line under single phase as well as two phase flow conditions. It is always easy in experimentation to investigate the thermo-hydraulic parameters in case of single phase flow of cryogen but it is real challenge when one deals with the two phase flow of cryogen due to availibity of mass flow measurements (direct) under two phase flow conditions. Established models have been reported in the literature where one of the well-known model of Lockhart-Martenelli relationship has been used to determine the value of quality at the outlet of Cryo transfer line. Under homogenous flow conditions, by taking the ratio of the single-phase pressure drop and the two-phase pressure drop, we estimated the quality at the outlet. Based on these equations, vapor quality at the outlet of the transfer line was predicted at different heat loads. Experimental rresults shown that from inlet to outlet, there is a considerable increment in the pressure drop and vapour quality of the outlet depending upon heat load and mass flow rate of nitrogen flowing through the line.

Steady State Superconducting Tokamak (SST-1) at the Institute for Plasma Research (IPR) is the first superconducting Tokamak in India and is an ‘operational device’. Superconducting Magnets System (SCMS) in SST-1 comprises of sixteen Toroidal field (TF) magnets and nine Poloidal Field (PF) magnets employing cable-in-conduit-conductor (CICC) of multi-filamentary high current carrying high field compatible multiply stabilized NbTi/Cu superconducting strands. SST-1 superconducting TF magnets are successfully and regularly operated in a cryo-stable manner being cooled with two-phase (TP) flow helium. The typical operating pressure of the TP helium is1.6 bar (a) and the operating temperature is the corresponding saturation temperature. The SCMS weighing a cold mass of nearly thirty two tons has a typical cool-down time of about 14 days from 300 K down to 4.5 K using helium refrigerator/liquefier (HRL) system of equivalent cooling capacity of 1350 W at 4.5 K. Using the available of experimental data from the HRL, we have estimated the vapor quality during the cryo-stable operation of the TF magnets using the well-known correlation of two-phase flow. In this paper, we report the detailed characteristics of two-phase flow for given thermo-hydraulic conditions during long steady state operation of the SST-1 TF magnets as observed in the SST-1 experimental campaigns.

Cable-in-Conduit Conductors (CICCs) are validated base conductors for fusion grade superconducting magnets. In practice, the CICC acts as a narrow cryostat that provides adequate cryostability with the direct contact of coolant fluid to conductor from inside. The superconducting magnets are cooled using forced flow (FF) supercritical helium or two phase (TP) helium, which flows through the void spaces of the CICC. Thermo-hydraulics studies using supercritical helium in single phase flows are well-known and established. On the other hand, the TP cooling with helium is still an area of active research. There are perceived risks of the TP cooled CICC running into flow chocking and possible thermoacoustic oscillations leading to flow instabilities; and hence traditionally are not favoured. This research work addresses the fact that TP cooling is an exciting cooling and operation regime with inherent parametric benefits. Our present study is an analytical study of forced flow two phase helium cooling in CICC wound superconducting magnets. The TP flow provides greater cryostability by the latent heat of helium compared to enthalpy, as in case with supercritical helium cooling of CICC. Analysis carried out predicts significant gains with TP cooling on a prototype CICC, which is circular in cross-section and appropriate for fusion devices for high magnetic field applications. These formalisms are general and extendable to any CICC wound magnets. This paper describes the analysis and advantages of the TP cooling over single phase cooling of a CICC.

In cryogenic two phase flow, it is always challenging to measure the quality and void fraction. In this regard, an effort has been made to indigenously develop an electronic circuit to measure the void fraction by measuring the capacitance of the order of picofarads accurately depending upon the dielectric constant of nitrogen in vapor and liquid phase. The state-of-art electronics card has been developed and tested successfully for its performance and validation. Using this card, an experiment has been conducted using liquid nitrogen cryo transfer line to study the two phase void fraction. In this paper, the design basis and working principle of the designed electronics card along with the performance results are discussed. A/D conversion and DAQ system has been implemented to display the direct measurement data in a computer.

The experiment was conducted at SIF of Chandra Shekhar Azad University of Agriculture & Technology, Kanpur during Rabi season of 2017-18. It was experiment consisted eight treatments of different nutritional doses of micro nutrient, organic manure, and micro-organisms, along with major nutrient with the objective to find out the effect of vermicompost, FYM, Azotobacter, PSB with chemical fertilizer on growth, treatment combination for wheat and assess the economics of the treatments. Due to balance nutrition in wheat variety Shekhar (K-1006). The experiment was organized under RBD with three replications. It was the soil of the field Analyzed medium fertility status concerning available NPK, S and Zn status of micronutrients. The treatment T₅ (RDF + Azotobacter + PSB + vermicompost @ 5 t ha^-1) found superior in terms of maximum root and shoot growth, yield attributes and yield the maximum grain yield (58.75 q/ha.), under recorded in T₅ (RDF + Azotobacter + PSB + vermicompost @ 5 t ha^-1) treatment compared to control treatment.