Cooling systems, basic design

In high-temperature gas turbines cooling systems need to be designed for turbine blades, vanes, endwalls, shroud, and other components to meet metal temperature limits. The concepts underlying the following five basic air-cooling schemes are (Figure 9-13) ... 

Now let us consider utility failure as a cause of overpressure. Failure of the utility supphes (e.g., electric power, cooling water, steam, instrument air or instrument power, or fuel) to refinery plant facihties wiU in many instances result in emergency conditions with potential for overpressuring equipment. Although utility supply systems are designed for reliability by the appropriate selection of multiple generation and distribution systems, spare equipment, backup systems, etc., the possibility of failure still remains. Possible failure mechanisms of each utility must, therefore, be examined and evaluated to determine the associated requirements for overpressure protection. The basic rules for these considerations are as follows ... 

In order that hot condenser water may be re-used in a plant, it is normally cooled by contact with an air stream. The equipment usually takes the form of a tower in which the hot water is run in at the top and allowed to flow downwards over a packing against a countercurrent flow of air which enters at the bottom of the cooling tower. The design of such towers forms an important part of the present chapter, though at the outset it is necessary to consider basic definitions of the various quantities involved in humidification, in particular wet-bulb and adiabatic saturation temperatures, and the way in which humidity data are presented on charts and graphs. While the present discussion is devoted to the very important air-water system, which is in some ways unique, the same principles may be applied to other liquids and gases, and this topic is covered in a final section. 

Discharge tube lamps for laboratory work usually consist of three basic parts the tribe to contain the discharge, the electrodes, and a water cooling system. Many diflerent types of lamp have been designed, and while a complete review is outside the scope of this book a few of the more simple ones may be described. 

Determine the consequence frequency for a cooling water failure if the system is designed with two IPLs. The IPLs are human interaction with 10-min response time and a basic process control system (BPCS). 

Industry Application and Basic Design of Cooling System... 

Because water treatment programs are required to perform under many different operating conditions and in several different types of cooling systems, some standardization of the design, selection, and subsequent application process is inevitable. This standardization can be useful in making it easier for buyer and seller to agree on suitable treatments and to quickly establish the basic criteria for cooperation and program success, and also the estimated annual costs or estimated annual value (EAV) associated with treatment application. 

Shown in Figure 9.2 is a schematic drawing of a basic dosing and control system, with design and layout typical of many cooling systems. 

This illustration from The Art of Distillation shows the basic design for the acetate work. The still pot on the furnace holds the acetate, then the vapor is led through a cooling system into a receiver. This will catch the bulk of the distillate. A cooling system leads off from this receiver to a second receiver which catches the more volatile spirits. 

While the designs of commercially available crystallizer cells have some variances, all are intended to cool and agitate the oil as a batch more or less in the same manner. There are, however, several types of filters in use based on the products and style of operation. These basic designs include plate and frame filters, continuous vacuum systems, membrane systems, and pressure leaf designs. 

To design a cooling system for the fuel cell stack the thermal parameters of the stack and its components had to be determined accurately. For this reason a 3D FV (finite volume) thermal model was created. Special emphasis was placed on the thermal conduction of the various layers responsible for heat flow in all directions of the fuel cell stack. The basic parameters are given in Table 8-1. 

Obviously, in space applications, weight, and possibly volume, impose severe limitations. Consequently a brief outline of some basic aspects in the choice and design of such cooling systems may be in order here. 

Cooling towers—devices used by industry to remove heat from water. In a typical tower, a boxshaped collection of multilayered slats and louvers directs airflow and breaks up water as it cascades from the top of the water distribution system. Cooling towers are classified by the way they produce airflow and by the way the air moves in relation to the downward flow of water. Basic designs include atmospheric, natural, forced, and induced draft. 

Plate distillation column system—has trays that are designed to enhance vapor-liquid contact in the distillation process. Plate columns may be bubble-cap, valve tray, or sieve tray. The basic components of a plate distillation column include a feed line, feed tray, rectifying or enriching section, stripping section, downcomer, shell, reflux line, energy balance system, overhead cooling system, condenser, preheater, reboiler, accumulator, feed tank, product tanks, bottom line, top line, side stream, and advanced instrument control system. 

Figure XIV-3 shows a general view of the 4S reactor for a 50 MW(e) plant although the size and dimensions differ from those of the reactor for a lOMW(e) plant, nearly all basic concepts are the same, except that the primary reactor cooling system (PRACS) is used in the 50 MW(e) design instead of the IRACS in the 10 MW(e) design.

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