Steam system optimization

Once the highest steam level is set, then intermediate levels must be established. This involves having certain turbines exhaust at intermediate pressures required of lower pressure steam users. These decisions and balances should be done by in-house or contractor personnel having extensive utility experience. People experienced in this work can perform the balances more expeditiously than people with primarily process experience. Utility specialists are experienced in working with boiler manufacturers on the one hand and turbine manufacturers on the other. They have the contacts as well as knowledge of standard procedures and equipment size plateaus to provide commercially workable and optimum systems. At least one company uses a linear program as an aid in steam system optimization. 

The efficiency of the Rankine cycle itself can be increased by higher motive steam pressures and superheat temperatures, and lower surface condenser pressures in addition to rotating equipment selection. These parameters are generally optimized on the basis of materials of constmction as well as equipment sizes. Typical high pressure steam system conditions are in excess of 10,350 kPa (1500 psi) and 510 °C. 

Complex steam systems usually feature many important degrees of freedom to be optimized. To establish the steam costs for retrofit of site processes requires an optimization model to be developed. This allows the steam loads for process heating to be gradually decreased and the steam system reoptimized at each setting. The result in cost... 

Optimal solution to steam system LP Variable Name Value Status... 

Most MEG plants are integrated with EO plants. In such an integrated EO/MEG facility, the steam system can be optimized to fully exploit the benefits of high-selectivity catalyst applied in the EO plant. However, standalone MEG plants have been designed and built. 

Most EO plants are integrated with MEG facilities. When only EO is required, a small amount of technical grade MEG is inevitably coproduced. In a combined EO/MEG plant, all MEG produced is fiber grade. In an integrated EO/MEG facihty, the steam system can be optimized to fully exploit benefits of the high selectivity catalyst. 

An important task of optimizing a steam system is to determine the most economical way to satisfy increasing and decreasing steam and power demands. This can be... 

No matter how much the steam system could be optimized, one relevant and important question is What is the maximal efficiency that the steam system can achieve The answer will be provided by the concept of cogeneration efficiency that is discussed next. 

Compared with the net fuel equivalent of 351 MMBtu/h for the steam system in Figure 18.4, use of the most efficient turbines can only achieve energy savings of 14 MMBtu/h (351 337). This indicates that the optimized existing steam system... 

What are the characteristics of an optimized steam system The main characteristics can be summarized as follows ... 

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