Pinch technology has now developed into a powerful tool for heat integration of petroleum refining processes. Each process within the refinery has its own constraints against pinch analysis. In order to overcome these constraints, many applications and their solutions have been presented, such as decomposition policy and pressure drop considerations. These studies show that pinch analysis will only be suitable within the known limitations. In traditional refineries, the hydrocracking process is considered important due to the high pressures. The process converts gas oil feedstock into kerosene, diesel fuel and high-quality gasoline. In this paper, we have focused on the retrofitting of a typical hydrocracking process at Tehran South Refinery (Chevron License) operating at 130-180 atm with significant energy consumption. The potential and opportunities for heat integration in this process were considered. The objective of this study is to demonstrate how to apply alternative heat integration approaches, recover the maximum waste heat and maintain stable production while taking into account the operational constraints and plant equipment limitations. In this survey, several projects were identified which resulted in $870 000 annual saving in energy costs.  2010 Curtin

Heat integration techniques are now widely used for energy saving in petroleum processes. In this paper, an industrial hydrocracking process (UOP license) is retrofitted by pinch analysis as a significant tool for heat integration. The hydrocracking process is a main important conversion process in oil refineries and there has been sustained effort to improve its energy efficiency. Application of pinch analysis in retrofit of this process shows the heat exchanger network is operated efficiently. However, a large amount of energy is wasted from the hydrocracking unit, which their condition make no of use directly by the process during pinch analysis. Actually, most of the refining petroleum processes use considerably more energy than the operational minimum energy requirements because of their energy losses. These external energy losses are due to many factors, including normally inefficient or outdated equipment and process design, inadequate heat recovery, and poor integration of heat sources and sinks. However, without identifying the quality of the energy losses, it is difficult to determine how much of that energy is feasible to recover under realistic plant operating conditions. This is where exergy analysis can significantly assist in determining energy recovery opportunities. Thus, this paper is addressed to researchers who are assessing the quality of energy wasted in hydrocracking process, by using the principles of both pinch and exergy analysis. Based on the result obtained, the flue gas exhaust and the high pressure drop in reaction section can be considered as the exergy loss sources in this process. Moreover, the portion of waste energy that can be practically recovered is quantified.

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Background: The purpose of this research is to study the solutions for improving the efficiency of a micro combined heat and power (m-CHP) system based on OHVG (OverHead Valve Gas fueled) engine. Method: In this regard, the effects of valve timing and changing the camshaft on the power and fuel consumption of the engine have been numerically and experimentally investigated. The tests have been performed for engine speed range from 1000 rpm to 3500 rpm, while the engine's fuel was natural gas. The numerical results are found to be in good agreement with experimental ones. The effect of changing the valve timing and camshaft on the performance of the m-CHP has been investigated through the experiments in the test room. The engine speed was 1500 rpm; output hot water was fixed at 55oC; and output electrical power varies from 8 kW to 13 kW in the experiments. Results & Conclusion: The experimental results of the engine test indicate that, by changing the camshaft for full load operation and speed 1500 rpm, engine torque and volumetric efficiency improved by 7.2% and 6.0%, respectively, and fuel consumption decreased by 0.8%. According to the results, the best point for the performance of m-CHP is close to the full load of the electrical power because by increasing the electrical load, electrical efficiency increases from about 25.9% to 32.3%, while the thermal efficiency decreases from about 61.9% to 56.1%.