Seawater specific heat

The freezing point, temperature of maximum density, osmotic pressure and specific heat for seawater of various salinities are given in Table 21.23. 

Stein et al. [673] have described a simplified, sensitive, and rapid method for determining low concentrations of cadmium, lead, and chromium in estuarine waters. To minimise matrix interferences, nitric acid and ammonium nitrate are added for cadmium and lead only nitric acid is added for chromium. Then 10,20, or 50 pi of the sample or standard (the amount depending on the sensitivity required) is injected into a heated graphite atomiser, and specific atomic absorbance is measured. Analyte concentrations are calculated from calibration curves for standard solutions in demineralised water for chromium, or an artificial seawater medium for lead and cadmium. 

As noted in Table 3 [77], the results of multiple alloy tests in seawater are correlated to the Pitting Resistance Equivalence (PRE) number [47,48,72,77], which also correlates to alloy pterformance in FeCly. Anderson [78] and Streicher [79] used MCA in seawater tests to compare alloy performance. More recently, a simple, flat, plastic (specifically, polymethylmethacrylate, which is often referred to as "perspex ) washer has been successfully used to evaluate a series of alloys in seawater [77]. One application of the ASTM G 48 test has been in simulating leaking tube-to-tube sheet joints in seawater heat exchangers and condensers [87]. When certain highly corrosion-resistant alloys were paired in a dissimilar metal crevice (DMC) with alloys that would be expected to suffer crevice corrosion in the particular test solution, the more corrosion-resistant alloy was found to corrode due to the accelerating effects of the corrosion products from the less resistant alloy. The results of DMC tests in ferric chloride were confirmed by long-term DMC exposures in seawater [82],... 

According to the design concept, the UNITHERM can be used as a source of energy for the generation of electricity, district heating, seawater desalination and process steam production either in a complex or to meet specific demands. The purpose of the NPP would impact not only the mix of components but may also determine the characteristics of the reactor [II-5]. For instance, the use of steam at low parameters for district heating and potable water production allows the application of a turbine generator unit operated at backpressure. This sufficiently increases total plant efficiency and allows the use of the thermal siphon as an... 

At this design stage, the systems for non-electric applications of the MBRU-12 were not considered in detail. Experience in the design of relevant systems for close parameters in the steam-water circuit (e.g., for the BN-350) makes it possible to conclude that the MBRU-12 could be adjusted for a cogeneration with seawater desalination and/ or district heating without any design-specific problems [XVI-3]. 

For heat exchangers on seawater duty, where long life is required, titanium may be used. Alternatively, Cu/Ni alloys may be selected, provided that the fluid velocities are kept within the range given in the specifications. Normally, seawater is permitted only on the tube side of a heat exchanger. On some high-pressure gas coolers, however, this is not possible because of the risk of tubes collapsing under external pressure. In such cases titanium tubes and shells are necessary to allow seawater to be used on the shell side. 

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