Insulation design

Used by permission Turner, W. C., and Malloy, J. F. Handbook of Thermal Insulation Design Economics for Pipe and Equipment, 1980. R. E. Krieger Publishing Company Joint edition with McGraw-Hill Book Company, Inc. All rights reserved. 

Insulation design is a classic example of overall cost saving that is especially pertinent when fuel costs are high. The addition of insulation should save money through reduced heat losses on the other hand, the insulation material can be expensive. The amount of added insulation needed can be determined by optimization. 

ADDmoNAL References ASHRAE Handbook and Product Directory Fundamentals, American Society of Heating, Refrigerating and Air Conditioning Engineers, Atlanta, 1981. Turner and Malloy, Handbook ofThermcd Insulation Design Economies for Pipes and Equipment, Krieger, New York, 1980. Turner and Malloy, Thermal Insulation Handbook, McGraw-Hill, New York, 1981. 

Figure 1. Insulation design for pressure vessel. The figure shows a vacuum space for obtaining good performance from the multilayer insulation, instramentation for pressure, temperature and level, and a vapor shield for reducing hydrogen evaporative losses.

Improved concepts of insulations have been developed for future large-size LH2 storage tanks, e.g. a spherical tank with inner / outer diameters of 36 m and 40 m, respectively, which means a volume of about 24,400 m or six times the NASA tank volume. The characteristic feature of the new insulation design is the partition of the interspace volume of approx. 9000 m into many (some 10 ) small insulation boxes which can be arranged as a combination of vacuum and foam layers on the inner tank wall. The insulation character is maintained even if a single box has lost its vacuum. Target boiloff is 0.1 % per day. Experimental and theoretical investigations have been conducted for... 

Fundamental latency, Si02 insulation Design High speed digital, optical analog, RF... 

Heat energy is transferred from one location to another by three different mechanisms conduction, convection, and radiation. In insulation design theory, the objective is to minimize the... 

There are obvious tradeoffs that must be made in controlling the various heat-transfer mechanisms. Figure 5.167 illustrates the contribution to total conductivity of each mechanism at three different temperatures. The most efficient insulation design, both thermally and economically, will vary depending on the application conditions. References 1 and 2 are basic texts on heat transfer for further study. 

The reactor vessel insulation design was modified only as necessary to incorporate the additional structure and the internal shaping required. The water inlet devices and steam outlet devices were... 

The only disadvantage resulting from improving the design of the in-vessel retention is lhat it required additional structure and a shaped internal boundary for the reactor vessel insulation design, which incurred a development cost. 

Vexler, G. Comibert, J. (Nordx Cdt., Inc.). Flame retardant dnal insulation design and cable construction for plenum applications. Can. Patent CA2421440, Sept. 10, 2004. 

Frequency dependence is very significant when an accurate transient simulation on a distributed-parameter line, such as an overhead line and an underground cable, is to be carried out from the viewpoint of insulation design and coordination in a power system. However, a simulation can be carried out neglecting frequency dependence if a safer-side result is required because simulation with frequency dependence, in general, results in a lower overvoltage than that neglecting frequency dependence. 

The tower-footing impedance is always represented as a resistance as in Table 2.4 recommended by guides on insulation design and coordination of transmission lines and substations [26]. However, it is not pure resistance, but shows an inductive or a capacitive nature (see Figure 2.40) as investigated by many authors [10,15,23,31]. 

These analytical results clearly show that the PW voltage in the BFO case is much higher than that in the case of no flashover. This is the reason the insulation design/coordination of a substation is based on the result in the flashover case. 

The results have indicated that the direct strike to a PW with 30 kA produces an overvoltage at a substation comparable to that in the BFO case with Iq = 100 kA. This fact should be carefully investigated, because this has not been considered in the standard insulation design and coordination of a substation. 

Ozawa, J. et al. 1985. Lighming surge analysis in a multiconductor system for substation insulation design. IEEE Trans. Power Appl. Syst. 104 2244. 

Kawamura, T. et al. 1995. An estimating method of a lighming surge for statistical insulation design of substations. lEE Japan WG Report. Technical Report No. 566. 

Electric Research Association. 1988. Rationalization of insulation design. ERA Report 44 (3). 

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