Steam heat exchanger

Steam-Heated Exchangers Steam, the most common heating medium, transfers its latent heat in condensing, causing heat flow to be proportional to steam flow. Thus, a measurement olsteam flow is essentially a measure of heat transfer. Consider raising a hquid from temperature Ti to To by condensing steam ... 

The PWR operates at a pressure such that cooling water does not boil as it passes through the core. It goes to a heat exchanger (steam generator) to form steam that leaves containment, and drives a turbine generator to produce electricity. 

Oil is to be wanned from 300 to 344 K by passing it at 1 m/s through the pipes of a shell-and-tube heat exchanger. Steam at 377 K condenses on the outside of the pipes, which have outer and inner diameters of... 

Steam to kerosone or gasoline Finned-tube heat exchanger, steam in 50-200 280-1140... 

Two dissimilar metals in contact in an aqueous environment does not necessarily give rise to galvanic corrosion. Turner [1990] cites an example of a shell and tube heat exchanger (steam condenser), containing aluminium brass tubes expanded into carbon steel tube plates. It could be anticipated that with the relatively large area of the noble aluminium brass, severe galvanic corrosion would occur on the smaller area of exposed steel resulting in a short service life. In fact the condenser had been in service for 26 years when the examination took place ... 

Kirillov P., Yuriev Yu., Bobkov V. 1984. Reference book on thermal - hydraulics calculations (nuclear reactors, heat exchangers, steam generators). M., Energoatomizdat Publishers, in Russian, p.296. 

In the PWR steam is generated at lower pressure on the secondary side of separate heat exchangers, steam generators. The steam drives one or more turbines connected to electric generators and is condensed to water by an external cooling system after the turbine. Except for the external cooling system (sea or river water, cooling towers, etc.), the steam-water flow systems are closed cycles. 

As motioned in Chapter 19, the name implies that a pressurized water reactor is cooled by hot high pressure water, either H2O (PWR, VVER) or DjO (PHWR). In the PWR and VVER types the coolant is also us as moderator whereas a separate D2O containing moderator tank is normally used in the PHWR type. These power reactor types have several things in common primary — secondary coolant circuits separated by heat exchangers (steam generators), a pressurizer to adjust primary system pressure and often diemical shim control for adjustment of the excess reactivity with fresh fuel. 

Steam-Heated Exchangers Steam, the most common heating... 

P.L. KIRILLOV, et al., Thermohydraulic Design Handbook (Nuclear Reactors, Heat Exchangers, Steam Generators) , 2 ed., Moscow, Energoatomizdat, 1990. 

Since the most common application of steam involves using its latent heat in a heat exchanger, steam jacket or coils, it is common practice to retiun the hot condensate to the boiler via a hot well. This creates the possibility that flammable solvents can be brought into the boiler area. Because the hot well maybe at a temperature of 80-90 °C, many comparatively high boiling solvents can reach the hot well above their flash point. 

Use duct firing of heat recovery steam generators. Increase steam generation through WHR from fired heater s convection section, heat recovery steam generators and process heat exchangers/steam generators... 

PWR reactor Nuclear reactor where the core power is transported by pressurized water which circulates in a system of primary circuits. The production occurs within a set of Heat Exchangers (Steam Generators), using the thermal energy contained in primary water (PWR = Pressurized Water Reactor). 

Carbon dioxide is often ignored in steam systems. However, when absorbed in water, it forms carbonic acid, which can be corrosive to all parts of the steam and condensate system. Its potential presence is frequently overlooked in the design of heat exchangers, steam traps, condensate systems, deaerators, and water-treating systems. Most steam systems require continual addition of makeup water to replace losses. Makeup water must be adequately treated, by demineralization or distillation, to remove carbonates and bicarbonates. If these are not removed, they can be thermally decomposed to carbon dioxide gas and carbonate and hydroxide ions. The ions will normally remain in the boiler water, but the caron dioxide will pass off with the steam as a gas. When the steam is condensed, the carbon dioxide will accumulate since is is noncondensable) be passed as a gas by the steam trap or if the condensate and carbon dioxide are not freely passed by the steam trap, become dissolved in the condensate and form carbonic acid. If carbonic acid is formed it can have a pH approaching 4 and be very corrosive to copper and steel. Even if both the gas and condensate are passed freely by the steam trap, the gas will become soluble in the condensate when subcooling occurs. If oxygen is present, the corrosion rate Is accelerated. 

I n addition to the seal applications mentioned above, molded graphite has many applications in areas where chemical resistance is the major factor. Such applications are found in chemical reactors, heat exchangers, steam jets, chemical-vapor deposition equipment, and cathodic-protection anodes for pipelines, oil rigs, DC-power lines, and highway and building construction. 

The derived correlation can be used for supercritical fluid heat transfer calculations, in circular and other flow geometries, for heat exchangers, steam generators, nuclear reactors and other heat transfer equipment, for future comparison with other datasets, and for verification of computer codes and scaling parameters between water and modeling fluids. This correlation can be also used for supercritical carbon dioxide and other fluids. However, its accuracy might be less in these cases. Some specifics of pressure-drop calculations were also listed in the paper. 

---