Generation of Heat Transfer Coefficient Data in Regenerator for Stirling Cycle Refrigeration System

This paper attempts to generate the data of heat transfer coefficient for regenerator in stirling cycle refrigeration system on the basis of available experimental data. The available data is based on assumption that the mode of heat transfer in regenerator is conduction. This data does not produce optimal design of regenerator. Heat transfer coefficient must be modified to account for heat transfer in a regenerator by all three modes i.e conduction, convection & radiation. The data for heat transfer coefficient is generated on the basis of experimental results available in literature of performance of various stirling cycle refrigeration systems with different designs of regenerator. These models can be used to predict the performance of stirling cycle refrigerator system on the basis of dimensions of regenerator. The models are validated and optimized. This paper also presents the effect of variations in regenerator dimensions i.e. regenerator length, regenerator diameter, wiremeshsize, wire mesh arrangement, and wire mesh materialonHeat Transfer coefficient of regenerator. This data for heat transfer coefficient for regenerator of Stirling cycle refrigeration system can be used for optimizing design of regenerator of stirling cycle refrigeration system or predicting performance of stirling cycle system accurately. ,

Development of a Condensation Refueling Gas Recovery System Based on Turbo Brayton Refrigeration Technique

Volatile organic compounds (VOCs) are emitted from the refueling of gasoline vehicles and trucks. Controlling these emissions has been an important issue since the late 2000s in China. We have recently developed a condensation refueling gas recovery system to recover the VOCs from gaseous wastes at a bulk gasoline terminal. In this system VOC vapor is condensed by a reversed turbo-Brayton cycle refrigerator. The recovery system has a capacity of 100 Nm3/hr at the lowest condensation temperature of 190K. It has been put into use since 2008. The achieved recovery efficiency is 96% and the emission of VOCs is less than 8 g/m3 at the exit of the recovery system.

Safety interlock and vent system to alleviate potentially dangerous ice blockage of top-loading cryostat sample sticks

A combined solution is presented for minimizing the safety hazards associated with closed cycle cryostats described by Swainson & Cranswick [J. Appl. Cryst.(2010),43, 206–210]. The initial solution is to install a vent tube with one open end deep inside the sample space and a pressure relief valve at the top. This solution works for either a cryogen or a cryogen-free (closed cycle) system. The second approach, which can be combined with the first and is applicable to cryogen-free cryostats, involves electrically interlocking the closed cycle refrigerator compressor to the sample space, so that the system cannot be cooled in the presence of a leak path to air.

Mechanical design of a dual-cryostat instrument for a high-field pulsed magnet

The engineering of a dual-cryostat for a pulsed-magnet instrument at the Advanced Photon Source is presented. The dual-cryostat independently cools the magnet coil (using liquid-nitrogen) and the sample (using a closed-cycle refrigerator). Liquid-nitrogen cooling may allow a repetition rate of a few minutes for peak fields near 30 T. The system is unique in that the liquid-nitrogen cryostat incorporates a double-funnel vacuum tube passing through the solenoid's bore in order to preserve the entire angular range allowed by the magnet bore for scattering studies. Second, the use of a separate refrigerator for the sample allows precise positioning of samples in the bore while minimizing magnet vibrations propagating to the sample during pulsed-field generation.