Design and fabrication of a long-life Stirling cycle cooler for space application. Phase 3: Prototype model

A second-generation, Stirling-cycle cryocooler (cryogenic refrigerator) for space applications, with a cooling capacity of 5 watts at 65 K, was recently completed. The refrigerator, called the Prototype Model, was designed with a goal of 5 year life with no degradation in cooling performance. The free displacer and free piston of the refrigerator are driven directly by moving-magnet linear motors with the moving elements supported by active magnetic bearings. The use of clearance seals and the absence of outgassing material in the working volume of the refrigerator enable long-life operation with no deterioration in performance. Fiber-optic sensors detect the radial position of the shafts and provide a control signal for the magnetic bearings. The frequency, phase, stroke, and offset of the compressor and expander are controlled by signals from precision linear position sensors (LVDTs). The vibration generated by the compressor and expander is cancelled by an active counter balance which also uses a moving-magnet linear motor and magnetic bearings. The driving signal for the counter balance is derived from the compressor and expander position sensors which have wide bandwidth for suppression of harmonic vibrations. The efficiency of the three active members, which operate in a resonant mode, is enhanced by a magnetic spring in the expander and by gas springs in the compressor and counterbalance. The cooling was achieved with a total motor input power of 139 watts. The magnetic-bearing stiffness was significantly increased from the first-generation cooler to accommodate shuttle launch vibrations

Fabrication and test of a space power boiler feed electromagnetic pump. Part 1: Design and manufacture of pump

A three-phase helical induction electromagnetic (EM) pump has been designed and built. This pump was designed for use as the boiler-feed pump of a potassium Rankine-cycle space electric power system. The pump is constructed of high temperature materials including a T-111 duct, Hiperco 27 magnetic material, nickel clad silver conductor wire, and a completely inorganic insulation system. The pump is designed to deliver 3.25 lb/sec potassium at 1000 F with a developed head of 240 psi while being cooled by 800 F NaK. At these conditions, the overall pump efficiency is expected to be 18%

Space storable propellant module thermal control technology. Volume 2 - F2/N2H4 propulsion module Summary report

Space storable fluorine/hydrazine tank module thermal control design for Jupiter missio

Vapor Compression and Thermoelectric Heat Pumps for a Cascade Distillation Subsystem: Design and Experiment

Humans on a spacecraft require significant amounts of water for drinking, food, hydration, and hygiene. Maximizing the reuse of wastewater while minimizing the use of consumables is critical for long duration space exploration. One of the more promising consumable-free methods of reclaiming wastewater is the distillation/condensation process used in the Cascade Distillation Subsystem (CDS). The CDS heats wastewater to the point of vaporization then condenses and cools the resulting water vapor. The CDS wastewater flow requires heating for evaporation and the product water flow requires cooling for condensation. Performing the heating and cooling processes separately would require two separate units, each of which would demand large amounts of electrical power. Mass, volume, and power efficiencies can be obtained by heating the wastewater and cooling the condensate in a single heat pump unit. The present work describes and compares two competing heat pump methodologies that meet the needs of the CDS: 1) a series of mini compressor vapor compression cycles and 2) a thermoelectric heat exchanger. In the paper, the CDS system level requirements are outlined, the designs of the two heat pumps are described in detail, and the results of heat pump analysis and performance tests are provided. The mass, volume, and power requirement for each heat pump option is compared and the advantages and disadvantages of each system are listed

Task 7 space storable propellant module environmental control technology

Design of thermal control system for cryogenic fluid storage tank

Coconut Oil Space Cooler

During summer months there is reliance on air conditioning (A/C), which is energy intensive in nature. The mass use of A/C units during peak hours taxes the energy grid significantly as a demand spike occurs during these peak hours. This demand spike requires an equal response in supply which disproportionately produces greenhouse gas emissions as reserve power plants come online to meet this demand. These reserve power plants, are relatively inefficient, and more expensive to run than base load plants. The Coconut Oil Space Cooler utilizes the latent thermal storage capabilities of phase change materials (PCMs) to provide a temporary alternative cooling solution to A/C during these peak hours. By taking advantage of daily temperature undulations, the Coconut Oil Space Cooler absorbs heat during the day, during peak hours, when the temperature is sufficiently high to melt the phase change material. It absorbs heat from the environment, cooling it in the process. At night when the ambient temperature falls below the melting temperature of the phase change material, the device is operated to solidify the phase change material by releasing the stored heat back into the surroundings. The device is best suited toward a desert climate where day & night temperatures can vary greatly. As the name states, the device utilizes coconut oil as the phase change material, two separate heat exchangers, a duct fan, pumps, an Arduino microcontroller, solenoid valves, and various hardware to achieve the cooling effect. The device is able to provide, on average, 1 ℃ cooling effect for about 40 minutes of operation. When the Coconut Oil Space Cooler is operated for a single hour, during peak load hours, for a month, it equates to monetary savings of $50; this is for Bay Area utility rates. Many aspects of the product’s design had areas for improvement and optimization: diameter vs length optimizations for the tube-in-tube heat exchanger would optimize heat transfer rate with total thermal storage capacity. Selecting specialized phase change materials for specific temperature conditions would further improve the efficacy of the device. Additionally, adding fins to improve conduction within the tube-in-tube heat exchanger would improve the heat transfer rate

Using LHC as injector and possible uses of HERA magnets/coils

This workshop discusses the various aspects of a high energy version of the LHC in the LHC tunnel, the basic assumption being that the LHC will be decommissioned. The possibilities to recycle LHC and the already stopped HERA are discussed in this paper.Comment: 8 pages, contribution to the EuCARD-AccNet-EuroLumi Workshop: The High-Energy Large Hadron Collider, Malta, 14 -- 16 Oct 2010; CERN Yellow Report CERN-2011-003, pp. 116-12

Preliminary design study of astronomical detector cooling system

The preliminary design of an astronomical detector cooling system for possible use in the NASA C-141 Airborne Infrared Observatory is presented. The system consists of the following elements: supercritical helium tank, Joule-Thomson supply gas conditioner, Joule-Thomson expander (JTX), optical cavity dewar, optical cavity temperature controller, adjustable J-T discharge gas pressure controller, and vacuum pump