Effectiveness of heat exchangers

Kraus, A D. and D. Q. Kem, The Effectiveness of Heat Exchangers with One Shell Pass and Even Numbers of Tube Passes, ASME, AlChE-ASME Heat Transfer Conference, Aug. 8, (1965). 

It supplies heat, by condensing, at a constant temperature and with high heat transfer coefficients, so it maximizes the effectiveness of heat exchangers ... 

Figure 9.85. Effectiveness of heat exchangers as a function of number of transfer units 1251...

Fig. 1.3. The effect of heat exchanger performance, NTU, and heat capacity ratio, h, on the normalized heat loss for heat-integrated processes in (a) countercurrent and (b) counter-cocurrent flow configuration.

The performance parameter of availability analysis is the second-law efficiency (The second-law efficiency has been termed effectiveness (3) but, to decrease confusion with the different "effectiveness" of heat exchangers, the term second-law efficiency is preferred.), denoted by hjj, and defined as... 

Hardt et al. [49] reached a similar conclusion, using computational fluid dynamics to study the effect of various fin configurations, as well as the effect of heat exchanger material conductivity on the overall performance of the microstructured equipment. 

Effects of heat exchanger tube leaks into the column include off-spec products and/or undesirable chemical reactions. In some cases, this reaction may lead to rapid corrosion or plugging. It is important to realize that material leaking at the condenser or at an intermediate exchanger may travel to the column base and decompose there. In one vacuum column, water leaking at the condenser reached the reboiler and caused a pressure surge and tray damage (358). 

Effects of heat exchanger tube leaks out of the column include inability to maintain column pressiure, erratic performance of reboiler or condenser, and erratic performance in other units because of contamination of the heat transfer medium. One classic experience (239) of an extremely sick column performance caused by a leaking reboiler was described in Sec. 1.2. 

Liquid viscosity data are needed for the design of fluid transport and mixing processes (e.g., pumps, pressure drops in pipes or pipelines, and stirred vessels) and have a significant influence on the effectiveness of heat exchangers and diffusion processes. The required accuracy for viscosity calculations is lower than for thermodynamic properties, but the correct order of magnitude must be met. 

The effects of heat exchanger fouling on the output temperature of hot stream arc modeled in Fig. 9c. This failure causes a disruption of the normal equipment state arid also an increase in the outlet temperature, i.e. T4(+l). 

Fig S 9 Effect of heat exchange through the wall on breakthrough curve and temperalure change of effluent stream... 

Previous models have dealt with only a single tube of the monolith. Two adjacent ducts are examined to see the effect of heat exchange between them when the velocity in each is different. 

To obtain h 2, we will first need to determine h. The latter is related to the effectiveness of heat exchanger C by... 

The overstress issue for the cooling water supply line due to the effect of heat exchanger flexibility must be resolved. 

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