Problem table, process integration

The problem table cascade for a process is given in Table 23.11 below for A7 = 30°C. This process is to be integrated with a steam turbine in a cogeneration scheme. The inlet steam is at 41 barg and 400°C. 

The development and application of the method can be illustrated by considering the problem of integrating the utilisation of energy between 4 process streams. Two hot streams which require cooling, and two cold streams that have to be heated. The process data for the streams is set out in Table 3.3. Each stream starts from a source temperature Ts, and is to be heated or cooled to a target temperature Tt. The heat capacity of each stream is shown as CP. For streams where the specific heat capacity can be taken as constant, and there is no phase change, CP will be given by ... 

Table 1 presents the description of the decision variables and constraints of the problem.The problem inequality constraints (constraints 3-21) are related to product specifications and safety or performance limits. The equality constraints 1 and 2 were included to model the heat integration between the atmospheric column and the feed pre-heating train. Another 18 process variables take part of the objective function, as... 

Except when sampling directly from the container for labile parameters, preparation methods generally involve between one and four comminution processes and three or four handling processes (e.g. sub-sampling, sieving), each of which has associated problems with respect to protecting the integrity of the sample. Table 3.3 identifies some common preparation processes and problems encountered in the laboratory. 

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