Passive heating

The metabolic energy generated by the core (M) is lost by (1) doing work, (2) respiration, (3) passive heat conduction to the skin, and (4) active blood flow to the skin. Any heat not transferred from the core is stored, with a resulting increase in core temperature. Work is energy that leaves the body as in... 

Passive heat exchanger equipment for air heat exchange is described in Section 26.4 and shown in Figure 26.5. This can only be used where the ducts are adjacent. Other methods are ... 

The dihydropyrimidinethione 30 has been obtained by microwave-induced rearrangement of a dihydrothiazine, using silicon carbide as a passive heating element <06JOC4651>. 

Passive heat-transfer enhancement techniques, retrofitted, 13 267 Passive mixers, in microfluidics, 26 966, 967 Passive noise detectors, 11 673 Passive nondestructive tests, 17 416, 425 Passive reactors, 17 555 Passive sensing materials, 22 706-707 Passive smart textiles, 24 625 Passive solar collection, silica aerogel application, 1 761-762 Pasta products, 26 278 Paste-extrusion process, 18 301-302 Paste forming, ceramics, 5 651 Paste inks, 14 315-316... 

Retro-Diels-Alder strategy, 21 148 Retro-ene reactions, 21 150 Retrofit (revamp) design, 20 724 Retrofitted passive heat-transfer... 

Merrill, T. L., Setoguchi, T., and Perez-Bianco, H. (1995) Passive Heat Transfer Enhancement Techniques Applied to Compact Bubble Absorber Design, Journal of Enhanced Heat Transfer, Vol. 

Tests in the EVA-II plant have shown that its operation at the same load is possible even if up to 30 % of the reforming tubes were blocked, meaning that isolation of single tubes would not disturb the operation thus increasing the plant s flexibility. Analytical studies have been conducted at JAERI to investigate the steam generator as a passive heat sink in case of a failure of the heat removal system of the reformer to ensure its coolability. 

Microwave-assisted reactions using nonpolar solvents such as toluene or hexane can still be heated to high temperatures using additives such as ionic liquids or passive heating elements. Ionic liquids heat extremely rapidly upon microwave irradiation. For example, heating 2 mL of pure hexane at 200 W in a monomode... 

The use of silicon carbide inserts has proved valuable in the uncatalyzed aza-Michael addition between piperazine and methyl acrylate. The reaction was low yielding using pure toluene as the solvent since the maximum temperature that could be attained was 170 °C. Adding the passive heating elements to the reaction mixture allowed for temperatures of 200 °C to be reached and, with this, a dramatic increase in the yield for the reaction was observed (Scheme 2.10). The product isolation procedure was trivial and consisted of physical removal of the heating element using a pair of tweezers followed by removal of the solvent. 

Using these figures, we first estimated the maximum possible passive heat dissipation of the notebook housing. Following the calculations of [13], under such conditions, a maximum heat of 100 W can be dissipated from the notebook surface by natural convection and radiation, which equals 17 W in total for a notebook of these dimensions, as summarized in Table 8-7. Thus, at 24 W power a total of 7 W would have to be actively drained by fans, and it follows that the entire additional ca. 24... 

Notebook constituent Maximum passive heat dissipation... 

State of the art heat sinks and miniature fans [16] capable of removing 24 W heat would occupy a volume of ca. 50 cm with an additional energy demand of 1.3 W for active cooUng or 100 cm for passive heat sink cooling. 

In comparison with the notebook, today s mobile phones have a much lower energy density. Using the same approach as above, we estimated the passive heat dissipation potential of a mobile phone housing with the following dimensions and boundary conditions ... 

The mobile phone and fuel cell produce, respectively, 0.6 W + 0.85 W = 1.45 W of waste heat during talk mode. Taking into account that at least 5% of the fuel cell heat is carried out with cathode airflow, the surface of the mobile phone should be large enough for passive heat removal, provided that the heat can be spread evenly. Nevertheless, the device would need openings for supply and removal of the cathode air. 

Use of the containment structure as a special system for keeping the core xmder water, and providing for passive heat removal from the reactor following primary circuit loss of integrity. 

For the small power RIs using LBC long-term passive heat removal through the reactor vessel into the environment is ensured without core damage in postulated accident with complete failure of heat removal and emergency protection systems. 

Third core heat removal system is a passive heat removal system (PHRS). The heat is removed from the monoblock to the water storage tank located around the monoblock vessel. This system ensures the reactor core cooling in case of postulated maximal accident with all secondary equipment failed, reactor protection system failure and total de-energizing of the NPP. 

In the 4S, following the loss of off-site power, the primary loop shifts to natural circulation. The pump in the secondary loop of the decay heat removal system does not work assuming the loss of emergency power following loss of off-site power. Under such conditions, the secondary coolant operates in natural circulation mode and natural air-cooling operates in the air cooler. Thus, a passive heat removal circuit is established. 

The core residual heat is designed to be dissipated by a passive heat transfer system. 

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