Cooling power

Fullwood, R. R. et al., 1976, ATWS A Reappraisal Part I An Examination and Analysis of WASH-1270, Technical Report on ATWS for Water-Cooled Power Reactors," EPRI NP-251, August. 

TABLE 6.11 Cooling Power of Wind on Ex(>osed Flesh Expressed as a Chilling Temperature, t hi under Almost Calm Conditions... 

COP, Coefficient of Performance, is equal ro cooling power per needed electric power... 

Kata cooling power The rate of cooling of a silvered or unsilvered kata thermometer due to the relationship between the air temperature and the air velocity over the bulb. 

Kata thermometer A thermometer that allows the air velocity to be determined by its cooling power. 

Due to its cooling power, water is the most effective extinguishing agent for many types of fire. It is particularly suitable for fires in carbonaceous materials. Portable extinguishers provide a limited quantity of water using gas pressure. Extinguishers should have a nozzle fitted so that the direction of the jet can be properly controlled. 

However, its cooling properties can be utilized when other materials are added to improve machining performance. One of the most common water-based cutting fluids is the so-called soluble oil, which, in fact, is not a true solution but an oiTin-water emulsion in which very fine droplets of oil are suspended in water. Such a fluid has very effective cooling power and the petroleum oil and its additives provide its lubricating and protective properties. 

In a crystal-pulling procedure using a tri-arc furnace (Fig. 2), a resistor box, a d.c. power supply (300 A, 80/40 V) and a set of water-cooled power cables are used to bring power and water to the electrodes. The upper part of the furnace is equipped with three equally spaced copper cathodes, to which are fixed W-Rh electrodes. The upper part (cathode) is separated from the lower part (anode) by a transparent quartz glass tube. In the bottom of the furnace there is a tapered opening for a water-cooled copper hearth containing the boride melt. All parts of the furnace are also water... 

The area of the total cooling surface of the mixing chamber and the rotors is estimated to be 6 m. The temperature of the cooling water was 30°C. The heat flux can be calculated by dividing the cooling power by cooling area, or... 

Figure 35.16 shows the fingerprints of the masterbatch mixing process, remill process, and final batchmixing process. The derivation of the data as mentioned above is clearly shown in the fingerprints. The results are summarized in Table 35.2. What can be seen is that cooling power is approximately one-third of the total power supply. Since the masterbatch cycle time is remarkably longer than the... 

Because PCM generally have low thermal conductivity, the problem of heating and cooling power was not discussed in the materials section. The usual approach to reach sufficient heat flux is by designing the system. 

Figure 124. Transport box from Va-Q-tec. Due to the vacuum super insulation a cooling power of less than 10 W by a PCM is sufficient to sustain —20 °C for 4 days in the box in a +30 °C environment (picture Va-Q-tec GmbH)...

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). 

A thermometer type of instrument used to measure the cooling power of air on the human body. 

A low value of L means a small cooling power, a serious drawback when cooling by evaporation. 

If we pump over a liquid (4He, for example), molecules of the liquid will evaporate producing the cooling of the remaining liquid. The cooling power will be ... 

Equation (2.6) shows that the cooling power decreases exponentially when temperature decreases, because pvap and the pump throughput vanish. 

A limit temperature is finally reached at which the cooling power supplied by the evaporating molecules is balanced by the external power input. In practice, this limit temperature is about 1.3 K for 4He and 0.3 K for 3He (see Fig. 2.6 and Chapter 5). 

When the cold system has reached a stationary state, the heat transferred from external sources or produced by the experiment must be compensated by the cooling power provided by the cryoliquid. 

Fig. 5.7. Working temperature of miniature refrigerator versus cooling power for two temperatures... 

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