Heat exchanger design superheater

Due to its required versatility, the platform should not be dependent on a particular design of the HTS electrolyser. Beyond the different possibilities of steam and air feeding the cathodic and anodic compartments of the electrolyser (mixed or not with H2) some key components are generic as the steam generator, both low- and high-temperature (recuperative) heat exchangers, the superheater. 

The dry expansion circuit does not have a liquid level which can be detected, and another type of signal must be used to control the valve. Dryexpansion circuits must be designed and installed so that there is no risk of liquid refrigerant returning to the compressor. To ensure this state, extra heat exchange surface is added to that needed, in order to heat the dry saturated gas into the superheat region. The amount of superheat is usually of the order of 5 K. 

NOTE Although superheater, reheater, and economizer heat exchangers all contain either steam or water in their respective tube bundles, they generally are not considered by boiler engineers and designers to be part of the steam-water circulation system s boiler surfaces. This distinction typically is reserved for the various tubes, connecting headers (manifolds), and drums that collectively provide the primary heat transfer and steam-generating facility. 

Application-Steam superheater Heat-exchange area = 15 m2 Base cost = US 6100 Design-type factor = 0.52 Design pressure factor = 1.4 Materials factor = 1. 0... 

The main equipment in the dehydrogenation reaction section of a Lummus/UOP Classic SM plant includes a steam superheater, two dehydrogenation reactors, a series of waste heat exchangers, and an off-gas compressor (Fig. 3). The equipment is designed to minimize pressure drop from the dehydrogenation reactors inlet to the off-gas compressor. 

The second unit in which a failure resulted in the mixing of water and sodium occurred in a superheater unit which was part of a steam generator with a per hour capacity of about 10 X 10 B.t.u. being tested at the MSA (8). This superheater, shown in Figure 6, was a tube and shell heat exchanger with sodium on the shell side and steam on the tube side. The unit was of double-barrier design with mercury as the third fluid. The third fluid was normally maintained at a pressure intermediate between the sodium and steam system pressures. 

The accident in a PFR superheater unit, a power plant of similar size to SNR-300 but of pool design resulted in breach of 40 bundle tubes. A larger number were damaged to a certain extent, as post-accident evaluations revealed. The containment boundary of the intermediate heat exchanger, however, was not affected. Subsequent calculations showed that there was a sufficient safety margin, so that nuclear safety was not impaired. 

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