Target temperature

The analysis of the heat exchanger network first identifies sources of heat (termed hot streams) and sinks (termed cold streams) from the material and energy balance. Consider first a very simple problem with just one hot stream (heat source) and one cold stream (heat sink). The initial temperature (termed supply temperature), final temperature (termed target temperature), and enthalpy change of both streams are given in Table 6.1. 

First, determine the shifted temperature intervals T from actual supply and target temperatures. Hot streams are shifted down in temperature by and cold streams up by AT J2, as detailed... 

The philosophy in the pinch design method was to start the design where it was most constrained. If the design is pinched, the problem is most constrained at the pinch. If there is no pinch, where is the design most constrained Figure 16.9a shows a threshold problem that requires no hot utility, just cold utility. The most constrained part of this problem is the no-utility end. Tips is where temperature differences are smallest, and there may be constraints, as shown in Fig. 16.96, where the target temperatures on some of the cold... 

Stream Supply - temperature (°C) Target temperature (°C) J. Heat capacity flow rate (MW°C b... 

When this equation holds, each stream match (exchanger) must provide that one of the two streams involved reaches its target temperature. Such a network is called acycHc. In an acycHc network, it is not possible to trace a closed path along stream lines from exchanger to exchanger and return to the starting point without retracing some of the path. 

Solvent must have sufficient volatihty to be easily removed at target temperature and vacuum levels. 

Cool (with agitation) to specified target temperature. The process state is Agitate with cooling. ... 

Stream Rowrate > specific heat Btu/hr °F Supply temperature, °F Target temperature, °F Enthalpy change lb Btu/hr... 

Stream Rowrate x specific heat kW/ C Supply temperamiE, °C Target temperature, C... 

Hypothermia Reduction of metabolic Target temperature of 32-34°C Bladder temperature Shivering... 

Metal atoms applied to the surface of a solid body under mild conditions (low target temperature and flow intensity) e.g., by means of an atom gun [25] (the method of molecular beams), provided that diffusion... 

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 ... 

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