Cold source

An inventor claims to have devised a CO. compressor that requires no shaft work. The device operates at steady state by transferring heat from a feed stream of 2 lb,/s of CO. at 150 psia and 100°F. The CO is compressed to a final pressure of 500 psia and a temperature of 40°F. Kinetic and potential energy effects are negligible. A cold source at -140°F drives the device at a heat transfer rate of 60 Btu/sec. Check the validity of the inventor s claim. 

Earth counteracts global warming by its natural cold sources. This has started to show as a temperature increase of ground, air and water. Ice fields and glaciers offer another huge cold reserve and the world s total non-renewable energy use would annually melt only about 0.003% of current ice, with present use of non-renewable energy and no other cold source. 

Some cold sources are natural sources (Figure 181) ... 

Figure 181. Natural cold sources as heat sinks to reject heat stored in the PCM...

Natural cold sources show the highest energy efficiency as cold is for free or with little energy consumption. However, they might have restrictions with respect to reliability (warm summer nights) and cooling power (small temperature differences). 

Some cold sources are artificial sources (Figure 182) ... 

Artificial cold sources show a lower efficiency than natural cold sources, as low temperature cold has to be produced. On the other hand, they are reliable as the chiller works independent of other climatic conditions. 

The applications of PCM (excluding natural or artificial ice) are usually using natural cold sources. The concepts can be divided into ... 

Extraction of potable water from saline waters by means of immiscible solvents has been shown to be theoretically possible, experimentally feasible, and economically attractive. Data presented show the process to be especially adaptable to the conversion of feed water in the range of 5000 to 10,000 p.p.m. It is adaptable to use of low-quality heat such as hot water from cooling towers or low pressure waste steam. By use of mixed solvent systems, the process can be optimized to take advantage of seasonal changes in temperature and sources of cold feed water and low-level heat sources. The process, in general, is somewhat more economical when a cold source of feed water is available. 

Figure 7 shows the process heat loop for transporting heat from the cold side of the PCU boiler to the hot side of the HTE boiler. This loop operates as a heat pump transferring heat from a cold source to a hot sink. Heat transfer with phase change is used at both the source and sink to achieve high heat fluxes and, hence, compact heat exchangers. An important question is the mechanical power consumption of the compressor and how it compares to the overall heat transfer rate. The compressor serves to... 

If sufficient positrons can be confined, studies of particle transport within the plasma, etc., similar to those conducted with electrons can be carried out. It may be possible to use the enhanced detection possibilities afforded since positron-electron annihilations can be detected. An ultra-cold source of positrons would also have a variety of other applications.24 For example, it has been proposed to eject trapped positrons into a plasma as a diagnostic.25 Also, positrons initially in thermal equilibrium at 4.2K within a trap would form a pulsed positron beam of high brightness when accelerated out of the trap. 

Hot or cold sources with temperatures far from the ambient temperature are useful. 

The exergy balance based on specified hot and cold sources yields... 

The temperature of the plasma varies from 2000 to 9000 K, depending on the position. By comparison, the flames used in FES are relatively cold sources. Micro-volumes of sample solutions are introduced at a constant flow with a pneumatic nebulizer via a third tube of small diameter directly into the inductively coupled plasma. The position in the plasma chosen for the measurement of light emission (either radial or axial), depends upon the element and whether an ionic or atomic spectral line is selected for the measurement. 

In the general case with adsorption data as reported in the literature, the gases are admitted from a hot or cold source to an adsorbent chamber kept at some constant-temperature level. In the adsorption data so obtained, there is intrinsically a lag due to heat-transfer effects. It can be shown, though, that this time lag is so small that it will not show up in the normal plots of pressure or volume versus time. 

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