Balance, heat

Fig. 2. Heat balance of the FCCU. Heat balance around the reactor A, heat balance around the regenerator B, and the overall heat balance around the entire

Now, carry out a heat balance within each shifted temperature interval, as shown in Fig. 6.20. 

Next, we carry out a heat balance within each shifted temperature interval according to Eq. (6.1). The result is given in Fig. 6.17. Some of the shifted intervals in Fig. 6.17 are seen to have a surplus of heat 

Since enthalpy interval k is in heat balance, then summing over all cold stream matches with hot stream i gives the stream duty on hot stream i  

Figure 6.20 Temperature-interval heat balances for Example 6.1.

J. L. Mauleon and J. C. CourceUe, "FCC Heat Balance Considerations with Heavy Feeds," presented at Katalistiks 6th MnnualFCC Symposium, Munich, Germany, May 1985. 

J. R. Murphy and Y. L. Cheng, "The Interaction of Heat Balance and Operating Variables in ZeoUtic Catalyst Operations," presented at Katalistiks 5th Annual FCC Symposium, Vieima, Austria, May 1984. 

J. L. Mauleon, J. B. Sigaud, and G. Heinrich, "FCC Heat Balance Management with Heavy Feeds, MTC Approach," presented at JPIPetroleum Eefmery Conference, Tokyo, Japan, Oct. 1986. 

Each of abovementioned processes of heat transfer is described by a set of equations of a heat balance, written for each Dirichlet cell. 

Fig. 6.7a. Above the pinch (in temperature terms), the process is in heat balance with the minimum hot utility Qnmin- Heat is received from hot utility, and no heat is rejected. The process acts as a heat sink. Below the pinch (in temperature terms), the process is in heat balance with the minimum cold utility Qcmin- No heat is received, but heat is rejected to cold utility. The process acts as a heat source.

For a cell, located close to an outer surface of a kiln the equation of heat balance can be written in the form  

Solution The fraction of liquid vaporized on release is calculated from a heat balance. The sensible heat above saturated conditions at atmospheric pressure provides the heat of vaporization. The sensible heat of the superheat is given by 

When the heat duty requirement, is specified and the fluid temperature change, AT, is fixed, as a result of operating or equipment limitations, the required volumetric pumping rate from the heat balance is 

The impact that variations in coke content and burning conditions can have on the overall heat of coke combustion is shown in Table 2. Because the heat balance dictates the amount of heat that is required from burning coke, the heat of combustion then determines the amount of coke that must be burned. 

Mass and energy balances are used to evaluate blast furnace performance. Many companies now use sophisticated computeri2ed data acquisition and analysis systems to automatically gather the required data for daily calculation of the mass and heat balances. Typical mass and heat balances are shown in Figure 4 and Table 5, respectively. 

Assuming a linear relation between surface temperature and corresponding vapor pressure of the condensable component allows a heat balance to be written from gas phase to the surface  

For example a process flow scheme for crude oil stabilisation might contain details of equipment, lines, valves, controls and mass and heat balance information where appropriate. This would be the typical level of detail used in the project definition and preliminary design phase described in Section 12.0. 

Fig. 6. Temperature—relative enthalpy plots showing network parameters of minimum utiUty for (a) the case requiring infinite area (b) where heat balance

Were we can give these equations for the heat transfer process along radius R. The other processes of heat transfer can be simulated analogously by changing formula for heat transfer area and distances between centers of cells. For Dirichlet cells, bordering a gas medium, an equation of heat balance can be written in the form  

Derivation of the working equations of upwinded schemes for heat transport in a polymeric flow is similar to the previously described weighted residual Petrov-Galerkm finite element method. In this section a basic outline of this derivation is given using a steady-state heat balance equation as an example. 

Overall comparison between amine and carbonate at elevated pressures shows that the amine usually removes carbon dioxide to a lower concentration at a lower capital cost but requires more maintenance and heat. The impact of the higher heat requirement depends on the individual situation. In many appHcations, heat used for regeneration is from low temperature process gas, suitable only for boiler feed water heating or low pressure steam generation, and it may not be usefiil in the overall plant heat balance. 

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