نشریه انرژی ایران
سال پنجم شماره 1 (پیاپی 25، امرداد 1380)

Process integration technology is now widely used in both energy saving retrofits and plant debottlenecks (due to increase throughput or modifications of process). It has been used in a variety of industries and approved to be reliable and application in engineering design. The main objective of this research is to find a methodology for retrofitting of an existing network for debottlenecking, using pinch technology. Debottlenecking may apply to a specific part of the unit or the entire unit. The most advanced method for debottlenecking, which is currently used, is based upon fixed-allowable pressure drops, in which a retrofit can be achieved without a need for pump and/ or compressor replacement. However, the existing algorithms do not consider optimum-pressure drops for the process streams; hence it may cause the following problems. 1. Capital investment for new exchangers would not be optimum. 2. Operating cost of the network tends to be sub-optimum. 3. Wrong targeting results causes wrong design initialization and hence wrong network topology. This work is going to resolve the above problems, by suggesting a new procedure for pressure drop optimization in debottlenecking. Application of the new procedure has made it possible to study pump and/ or compressor replacement towards optimum values for additional area, as well as operating cost of the network. This means a three-way trade-off among cost of additional area, pumps and compressors investment, and reduction or increase of electricity cost. The new algorithm has been effectively applied to a Crude Oil Pre-heat Train, subject to some 20% increase in throughput, and the corresponding results proved to be accurate enough. Namely, the results of targeting stage showed a very good agreement with final detailed design.

This writing is an attempt in search of adoptable policies for the optimization of Gasoline consumption, and bringing going the price of this commodity closer to its actual or real price. LEVELS: thus, per capita gasoline consumption are estimated on the basis of trends, and then total and per capita gasoline consumption are estimated by relying on an econometrics model inclusive of the long term, short term and trail and error, minor long term and short price elasticties are estimated and provisional forecasts are made on total and per capita gasoline consumption. Results are indicative of low price elasticity in the short term, and considerable growth of this elasticity in the long term. This point to the increasing role of market forces, especially the price in the long term, provide that the long term potential for consumption optimization through relative price – increases, exists, finally, authors by relying on the fact that elasticity is not just one parameter, recommend a series of reforms parallel and in coordination to price increases to achieve gasoline consumption optimization, that will pave the way for lowering obstacles and limitations to price increases and consolidate them.

Bread is considered as the most important product in Iranian families food diet. Iranian breads are baked in conventional ovens, under direct or indirect flames, which causes the bread not to be of a good quality. Using of adequate heating technique like microwave in which there is no need to thermal gradient for energy transformation, reduces pert of bread and energy usage. For considering the energy consumption in bread baking the moisture and temperature changes during baking barbari (a kind of Iranian bread) are measured in two method of microwave and conventional The analyses of results showed that for low final temperature of product in microwave baking, the necessary energy measured for heating of dough is about 6% and total need energy is 25.7% less than usual baking. The output energy is also equal to 56.5% in microwave baking and the time of baking is about 6.5 time less than conventional baking. The results also showed that the critical moisture is equal to 34%.