Define Key Indicators

Steam letdown valves are used to give steam supply flexibility and temperature control. However, letdown steam represents lost opportunity for power generation. Steam balance optimization could minimize the letdown steam flow and henee reduee the loss in power-generating potential. 

Do not forget the basic energy management, which includes maintenance, steam leaks, steam trap management, condensate return, and insulation. These elements are very visible on site and the energy loss can be estimated. Typically, around 10% steam production can be reduced in steam boilers from better housekeeping management. 

1 Understanding the Process In this example, the process objective is to 

2 Understanding the Energy Needs The following items are identified as major energy users in the reaction circuit and their distinct roles and significances are discussed next  

3 Effective Measures for the Energy Needs Based on the above understanding of the energy needs, we can go one step further to develop efficiency measures in providing these needs  

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The intention of defining key indicators is to describe the process and energy performance with a small number of operating parameters. A key indicator can be simply an operation parameter. Some examples of key indicators are reaction temperature, distillation temperature and pressure, column overhead (ovhd) reflux ratio, column overflash, spillback of a pump, heat exchanger U value, and so on. The parameter identified as a key indicator is important due to its significant effect on process and energy performance. 

Clearly, hydrocracking is a complex process. To simplify the overall task of defining key indicators for the whole unit, we can divide it into three sections reaction, product fractionation, and debutanizer or naphtha stabihzer. The naphtha stabilizer section is not shown in Figure 4.1. The goal is to define a set of key indicators for each section, which can be used for monitoring and optimization. 

Based on the kno vledge of the processes of T cell sensitization by chemicals and the importance of T cells in induction of autoimmune diseases a number of key indicators of autoimmunogenic compounds can be defined. These include the possibility to be subject of metabolic conversion (either intra- or extra-hepatically), the capacity to activate dendritic cells, to induce cytokine production (in any cell type), or the potency to cause cell stress or cell death. Most of these processes can be studied in vitro, but none of the available methods have been tested for this purpose and often chemicals may behave completely different in vitro than in vivo. However, much can be learned from initiatives to design alternative methods for contact allergens, as many of these basic processes that lead to T cell sensitization are similar for allergenic and autoimmunogenic chemicals. 

Group targets for the year 2000 are defined in the CER for all key indicators. They are of excellent quality and are clearly reported against. They include the following main environmental targets ... 

Developing Key Indicators for the Energy Needs Based on the understanding of major energy needs and measures of effieiency in providing the needs, we can define the following key indicators for the fractionation section ... 

For example, Cs% in the debutanizer overhead product represents the high value component C5 lost in LPG. The key indicator could be defined as the difference of actual 5% in LPG and C5 specification. If LPG produced from the column is... 

For each key indicator, a target is established as the basis to compare with current performance. The difference between the target and the current performance for each key indicator defines the performance gap. Different gap levels indicate the severity and level of urgency for actions. 

In a third step, a sensitivity analysis is carried out. Here, the defined key modules are assessed with regard to their costs and manufacturability. Furthermore, other important factors as, for example, resource availability, technological requirements and the potential for outsourcing parts of the manufacturing process are included in the analysis. Moreover, the modules suitability for assembly is the subject of the sensitivity analysis. If the results of the analysis indicate any insufficiency, the module development process has to be repeated. 

Phase III Data for system representation To achieve a correct representation of the system, is commendable to set up the interesting events from which to characterize to the system. In this case, the events of interest can correspond to the changes in the states of the equipments and of the system. Already defined the equipments and system events, it can be possible to proceed to bunch the events by its type, taking into account the study approach. In this case, the events are bunched generating the periods between detentions, the periods of the detentions (Scheduled or not) and the key indicators of the system. 

As we can appreciate, the differences between both methodologies are relevant, so that is imperative to define which is the most assertive to represent the behavior of the system. For this it will be analysed from two perspectives. The first one is to construct the representative models of the system and the second one the construction of key indicators of the performance, specifically, the utilization of the equipments. 

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