Present status of developments in physical sorption cooling for space applications

Performance comparison of sorption compressors for methane using metal-organic frameworks and activated carbon as adsorbents

“…dq input is consumed by the sensible heats for the adsorbent (dq sor,sen ), adsorbed phase (dq ads,sen ) and free gas (dq fre,sen ), and the heat of adsorption (dq ads ), written as, dq input = dq sor,sen + dq ads,sen + dq fre,sen + dq ads (5) The mass of the adsorbent and adsorbed phase can be regarded as constant in each small step. According to the first law of thermodynamics for a closed system [30], the sensible heats for the adsorbent and adsorbed phase are given by, dq sor,sen = du sor (6) dq ads,sen = du ads (7) where du is the change in internal energy. The volume changes of the adsorbent and adsorbed phase are small and their contribution to the internal energy can be neglected.…”

“…However, due to the limited adsorption characteristics of these two adsorbents, research on sorption compressors had been stagnant for years. Presently, the physisorption compressors mainly use activated carbon as adsorbents [7], whereas helium-3 [8], helium-4 [9], hydrogen [10], neon [11], nitrogen [12], argon [13], oxygen [13], methane [14], krypton [15], xenon [16], ethylene [17], gas mixture of nitrogen and hydrocarbons [18] are used as working fluids. However, it is found that due to the low adsorption capacities of activated carbons at room temperature, they often need to be precooled below ambient temperature to obtain considerable adsorption capacities, which will increase the complexity of sorption compressors.…”

In-flow measurement of the composition of a binary gas mixture

“…The application of gas mixtures has been researched in combination with mechanical compressors to offer higher cold-stage efficiencies at lower pressure ratios [4,5]. If vibration-free cooling is desired, which for instance is beneficial for cooling optical detectors, then thermally-driven sorption-based compressors provide an attractive alternative compared to mechanical compressors [6,7,8,9,10]. Sorption compressors operate on basis of cyclic adsorption and desorption of a working fluid on a sorber, realized by cyclic heating and cooling of the sorber material.…”

A 1-dimensional dynamic model for a sorption-compressor cell

“…Sorption-based cooling/heating technology has received much attention in recent years due to its unique advantages. It is attractive in the cryogenic temperature range to cool varies scientific instruments because it is vibration free, EMI free and it has a long lifetime [1]. The HVAC industry widely uses sorption-based technology for combined cooling, heating and power systems since sorption systems usually use environmentally-friendly refrigerants and are able to harvest low-grade heat [2].…”