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What is the specific function of the temperature control bypass in the high-pressure heat exchanger for diesel hydrogenation feedstock and reaction effluents? In my opinion, the cross-line is intended to control the feed temperature; if the temperature of the feed entering is too high, it can be quickly reduced through the cross-line. What are the requirements for the temperature of the highest heat separator? What are the effects of high or low temperatures? What are the temperature requirements for the thermal high-separator? In my opinion, the temperature control during heat cracking should be kept within a reasonable range to facilitate the separation of heavier and lighter components. If the temperature is too high, diesel components other than hydrogen and light components may be carried away; if the temperature is too low, the dehydrogenation effect will be poor

As the material coming from the heat high-pressure unit enters the distillation tower, it usually only exchanges heat with the product at the bottom of the tower; there is thus a limited range of control options. To regulate the feed temperature to the distillation tower, it is necessary to ensure that the temperature of the material coming from the heat high-pressure unit has some margin for adjustment – in other words, its temperature must fall within an appropriate range. Therefore, a control mechanism must be installed between the reaction products and the heat high-pressure unit. High-pressure heat exchange between the feedstock and the reaction effluent is used to control the temperature of the hot high-pressure stream ； The high-temperature fractionation temperature must meet the temperature requirements for the feed to the distillation tower ； The high temperature in the heat separation section is too high, and the feed temperature to the fractionation tower is out of control ； When the high-temperature fractionation temperature is too low and there is insufficient heat source for the product at the bottom of the distillation tower, the feed temperature cannot meet the requirements.

Personal understanding: The high-temperature control crossover is used to regulate a high temperature under normal operating conditions, and can be employed to reduce the temperature at the reaction inlet under abnormal conditions. If the temperature is too low, ammonium salts and polycyclic aromatic hydrocarbons tend to precipitate; this increases the energy consumption of the distillation system. If the temperature is too high, it raises the load on the high-pressure air cooling system, and an increase in hydrocarbons in the recycled hydrogen affects its purity